field

wweth institute.
Ci-ub library.

/fgsfiyy

Library
of the

University of Toronto

Digitized by the Internet Archive
in 2017 with funding from
University of Toronto

https://archive.org/details/objectsformicrosOOclar

Scales of Beetles and Fishes.

Frontispiece.

a

7

1. Weevil, natural size. 2. Scales of Weevil, magnified 100 diameters.

3. Scales of Green Weevil, magnified 150 diameters. 4. Scale of Perch, magnified 4 diameters.

' 5. Lines on Perch’s scale, magnified 100 diameters. 6. Scale of Sole, magnified 9 diameters.

7. Piece of Bel’s Skin, magnified 4 diameters.

8. Upper and under layers of Eel-skin, and Eel scales. 9. Scale of Eel, magnified 50 diameters.

OBJECTS

FOR THE

MICROSCOPE

A POPULAR DESCRIPTION OF THE MOST
INSTRUCTIVE AND BEAUTIFUL SUBJECTS FOR
EXHIBITION OR EXAMINATION.

By L. LANE CLARKE.

EIGHTH EDITION .

ILLUSTRATED WITH COLOURED PLATES.

LONDON :

GROOMBRIDGE AND SONS.

1889.

*

CONTENTS.

ON THE USE OF THE MICROSCOPE.

PAGE

Directions for Mounting Objects ... ... ... ... ... 6

,, ,, Mounting in Balsam... ... ... ... .. 7

PART I.

OBJECTS FROM THE VEGETABLE KINGDOM.

CHAPTER I.

Shapes of Cells — Cell-contents — Oil Cells — Hairs of Plants —
Cuticle and Stomata — Cuticle of Yucca, of Aloe, of Deutzia
Scabra, of Amaryllis, of Ind'an Corn, of Saccalobium,
ofElseagnus, of Tillandsia, of Onosma, of Opuntia ... .. 9

Rawhides. — Cuticle of Hyacinth — Raphides from Rhubarb —
Anagallis — Spiral fibre — Spiral Cells of raOucidium — Spiral
Vessels of Collomia — Spiral Cells of Balsam —Spiral Cells of
Sphagnum - Scalar iform Vessels 19

Pollen — Pollen of Mallow, of Hollyhock, of Passion-flower, of
(Enothera — A few words more on the Pollen — Pollen-tubes
—Stamens ... ... ... ... ... ... ... 23

Seeds. — Poppy — Sweet-William — Silene, or Stellaria — Orchis —

Eccreraocarpus or Calampelis ... ... ... ... ... 28

CHAPTER II.

SECTIONS OF WOOD.

Ruscus — Whanghae Cane— Asparagus — Section of Hazel, of Pine,
of Yew — Cedar of Lebanon — Vegetable Ivory — Fossil Coni-
ferous Wood — Pine Wood — Section of Cocoa-nut, of Cob-nut,
of Snake-wood ... ... — ... ... ... ... 29

Moss. — Slides of Dicranum, Funaria, Etc., Etc. — Spore-cases of Fern
— Slaters of Equisetum — Elaters of Jungermannia — Junger-
mannia Bidentata . ... ... ... ... ... ... 32

Fungi. — Slide of Puccinia, or Phragmidium — Blight of Wheat

(Smut)— Uredo Foetida, or Bunt — Uredo, or iEcidium ... 39

iv

CONTENTS.

CHAPTER III.

INFUSORIAL EARTHS.

PAGE

Diatoms of Guano — Naviculae— Navicula Hippocampa -Pleuro
sigma — Meloseira — Meloseira Borreri — Achnanthes Longipes,

— Synedra Ulna — Bacillariae — Goraphonema — Licmophora —
Rhabdonema — Grammatophora Marina — Biddulphia — Am-
phitetras — Isthmia Obliqua — Arachnoidiscus — Heliopelta —
Actinocyclus — Asteromphalus Astetolampra — Coscinodiscus 42

Desmidiacece. — Volvox Globator — Closterium — Confervae — Zyg-

nema — Achy la Prolifera... ... ... ... ... ... 50

PAET II.

OBJECTS FROM THE ANIMAL KINGDOM.

CHAPTER I.

OBJECTS FROM THE ARACHNIDA.

Spider’s Foot — Spider’s Legs — Spider’s Spinnarets — Spider’s

Eyes — Spider’s Jaws — Spider’s Palpi — Epidermis of Spider 57

CHAPTER II.

INSECT PARTS.

Tongues of Insects — Tongue or Proboscis of Hive Bee— Tongue of
Wasp — Butterfly’s Tongue or Proboscis — Proboscis or Tongue
of Blow-flv — Proboscis of Tabanus, of Gnat, of Empis-fly, of
Dioctria — Head of Conops, of Rhingia, or Syrphus,
of Drone-fly, or Heliophilus, of Eristalis, of Tipula, of Lim-
nobia, of Hemerobious, of Panorpa— Tongue of Cricket —
Gizzard of Cricket — Mouth of Soldier-beetle, Calathus Castel-
loides, of Brachinus, of Onthophagus, of Anchomenus, of
Crioceris, of Ladybird, of Stenopterus Rufus .. ... ... 64

Antennae. — Antennae of Cockchafer, of Nitidularia. of Hydrophilus,
of Elater, of Syrphus, of Blow-fly, of Bee, of Ichneumon, of
Argynnis — Palpi of Argynnis — Antennae of Dragon-fly, of
Silkworm-moth ... 79

Spirccdes and Tracheae. — Spiracles of Dytiscus — Traheae of Dy-
tiscus- -Spiracles of Cockchafer, of Fly, of Tipula, of Water
Larvae — Aerating Leaflet of Libellula — Abdomen of Ephe-
mera, or Spiracles ... ... ... ... ... ... 83

CONTENTS.

V

PAGE

Circulation of Blood ... ... ... .. .. ... ... 85

Spiracles of Larva of Bot-fly... .. .. ... ... ... 86

Wings of Insects. — Wing of Scatophaga, of House-fly, of Blue-
bottle-fly, of Syrphus, of Midge, of Gnat, of Beetle, of Cricket 86

Scales of Insects . — Scales of Morpho Menelaus, of Polyommatus
Argus, of Hipparcliia Janira, of Pontia Brasscia, of Silkworm-
moth, of Clothes- moth, of Podura, of Lepisma Saccharina ... 91

Elytra of Diamond Beetle ... . .. ... ... .. ... 94

Feet of Insects. —Foot of Syrphus — Leg of Dytiscus, or Dyticus
— Foot of Wasp, of Ophion, Leg of Bee, of Gyrinus, of Bra-
chinus, of Anchomenus, of Calathus Castelloides — Sting of
Wasp and Bee, of Gnat, of Tabanus .. ... . .. 94

Egg of Bot-fly, or (Estrus . 98

CHAPTER III.

INSECTS MOUNTED WHOLE.

The Telephorus, or Soldier-beetle — Helphorus Granularis -

Catheretes Urticse — Coccinella, or Lady-bird 100

Hemiptera. — Yelia Rivulorum — Notonecta, or the Water Boatman
— Reduvius, or Bed-bug— -Cimex, or Field-bug — Aphis —
Aphrophora, or Cuckoo-spit — Thrips ... 106

Hymenoptera. — Tenthredo, or Saw-fly — Cypheus Pygmseus — Ihc-
neumon-fiy — Microgaster Glomeratus— Aphidius l Avenge —
Ephedrus Plagiator— Ceraphron Carpenterii — Chelymorpha
Phyllophora, or the Turtle-shaped Leaf-bearer 110

CHAPTER IV.

DIPTERA.

Culex Pipiens ... ... 120

Ptychoptera ... ... ... ... ... ... 124

Scatophaga — The family of the Brachycera— the Scatophaga —
Lonchoptera — Bibeo — Dolichopus — The Opomyza — Chlorops
— Phoro — Leptis — Asilus — Empis Empis Stercorea —
Hilara— Syrphus Pyrastri— Borborus Equinus — - Sepedon—
Sepsis ... ... ]25

The Halteres . Poisers , of Diptera. — Halteres of Blow-fly— Hal-
teres of Tabanus ... ... ... ... ... 140

VI

CONTENTS.

CHAPTER V.

PARASITES

PAGE

The Flea. — The Pygidium of a Flea .. ... ... .. ... 144

Pediculus, or Louse ... . ... ... ... ... 146

The Acari , or Tics, Mites.— Acarus Domesticus, or Common
Cheese-mites — Acarus Passularum — Acarus Passerinus —
Ixodes, or Dog-tick — Melophagus — Stenopteryx — Ornitho-
myia — Nycteribia — Chlifer — Acarus Gamasus — Trombidium
Phalangii —Trombidium Autumnale— Water-mites — Entozoa 147

CHAPTER VI.

MICROSCOPIC MOTHS.

Nepticula Aurelia — Nepticula Malvelli — Nepticula Prunatori —
Nepticula Trimaculella — Ceriastoma — Scitella — Lithocolletis
Sylve'Ia — Lithocolletis Schreberella — Lithocolletis Trifas-
cieila — Lithocolletis Hortella — Gracilaria Swederella — Gra-
cilaria Syringella — Coleophora Gryphipennella — Ornix
Guttea — Lithocolletis Scabiosella — Glyphipteryx Thrasonella
— Head of Ochsenheimeria, &c. . ... ... ... ... 153

CHAPTER VII.

PALATES.

Palate of Helix Pomatia —Helix Aspersa — Limax — Helix Hor-
tensis — Helix Nemoralis — Helix Rufescens — Helix Vigata
— Zonites, or Helix Nitida — Palate of Whelk, of Purpurea,
of Nasa, of Trochus Ziziphinus, of Trochus Crassus, of
Trochus Umbilicatus, of Periwinkle, of Haliotis, or Aumer,
of Pleurobranch, of Aplysia, of Doris, of Limpet, of Chiton,
of Yellow Nerite, of Neritina Fluviatilis, of Lymneus Stag-
nalis, of Planorbis Cornea, of Paludina, of Cyclastoma ... 158

CHAPTER VIII.

SLIDES OF ZOOPHYTES.

Anthoza. — Sertularia Pumila — Sertularia Polyzonias — Sertularia
Operculata — Sertularia Rosacea — Laomedea Geniculata —
Laomedea Dichotoma — Plumularia Cristata — Plumularia
Falcata ... ... ... ... ... .. ... .. 167

Polyzoa. — Gemicellaria — Gemmellaria Loriculata — Gemecelaria,
or Notomia Bursana — Cellularia Avicularia — Flustra Trun-
cata — Pustulipora Fpssil — Flustra Chartaceae — Cellularia
Reptans — Cellularia Ciliata — Crisea Eburnea — Crisea Cornuta
— Serialaria Lendigera — Fresh- water Zoophytes ... ... 171

CONTENTS.

VU

CHAPTER IX.

SEA-WEEDS — MARINE ALG.E.

PAGE

Marine Algae— Callithamnion — Ceramium — Ptilota Plumosa —
Plocamium Vulgare, Coccineum — Polysiphonia — Spheio-
coccus — Griffithsia — Gracillaria — Laurentia — Odonthalia—
Bonnemaisonnia — Delesseria — Rhodomela — Spyridia Fila-
me n tosa — Chaetospora Wiggii — Haly menia — Da sy a — Dasy a
Arbuscula — Dasya Occellata — Dasya Venusta — Goadby’s
Solution for Marine Algae ... ... ... ... ••• 181

CHAPTER X.

FORAMINATED SHELLS.

The Operculina— Fossil Foraminated Shells from Barbadoes —

Orbitolites — Nummulites ... ... ... ... ... 194

CHAPTER XI.

SPICULES OF SPONGES.

Spicules of Sponge — Gemmules of Pachymatisma — Spicules of

Grantia Nivea ... ... ... ... ... ... ... 193

CHAPTER XII

SECTIONS OF BONE.

Man’s Metacarpal — Fin-bone of Lepidosteos — Femur of Tetrao

Urogallus ... ... ... ... ... ... ... ... 201

Sections of Teeth. — Sections of Human Tooth ... 204

CHAPTER XIII.

HAIRS.

Human Hair — Hairs of Dormouse and Common Mouse, of Mole,
of Bat, of Elephant, of Camel, of Reindeer, of Ornitho-
rhynchus, of Larva of Dermestes ... ... ... ... 206

CHAPTER XIV.

SPICULES OF HOLOTHURLE.

Spicules of Synapta — Spicules of Chirodota — Calcareous Spicules
of Doris— Calcareous Skeleton of Doris — Spicules of Gorgonia
— Spicules of Alcynonium Digitatum— Section of Echinus
Spine ... 208

viii

CONTENTS,

OBJECTS FOR POLARISCOPE.

PAGE

Polarized Light — Selenite — Rhinoceros Horn — Whalebone —
Elytra of Dytiscus — Cuticle of Deutzia Leaf — Section of
Quartz — List of Objects ... ... ... ... .. .. 212

CHAPTER XV.

ANATOMICAL INJECTED PREPARATIONS

Liver : Human, Rabbit, Pig, Monkey — Villi, Small Intestines of
Man, of Monkey, of Pig. of Tog, of Cat, of Rabbit — Duode-
num of Mouse — Lung : Human, Monkey, Bear, Puppy, Pig,

Cat, Sheep, Fowl, Goose, Turtle, Rattlesnake, Frog, Tortoise,

— Gill of Eel — Fin of Turtle — Stomach of Mouse— Skin —
Palm of Hand — Foot of Cat- Skin of Toad — Ciliary Pro-
cesses—Eye of Ox — Ear of Mouse— Toe of White Mouse —
Kidney — Tongue: Human, Dog, Cat, Mouse — Brain: Human,

Cat, Rabbit, Mouse ... ... ... ... ... ... 216

CHAPTER XVI.

SLIDES OF CRYSTALLIZATION.

Selenite — Acetate of Copper -Sulphate of Copper — Alum — Oxa-
lurate of Ammonia — Murexide, or Purpurute of Ammonia —
Hydrochlorate, or Muriate of Ammonia— Oxalate of Am-
monia— Salt of Brucia — Iodo-disulphate of Quinine — Borax,
or Bi-borate of Soda — Boracic Acid — Sulphate of Magnesia —
Ammonio-Phosphates of Magnesia — Uric Acid, or Lithic Acid
— Nitrate of Potash, or Nitre — Saltpetre — Salicine — Nitrate
of Silver 224

OBJECTS FOR THE MICROSCOPE,

ON THE USE OF THE MICROSCOPE.

Although a minute description of the construction of the
microscope would be out of place in this small work, and
involve more of the science of optics than could be under-
stood without diagrams and much knowledge of the laws
of light, yet it will be useful to give a few hints on the
practical management of a newly-purchased instrument.

Assuming the student to be desirous of obtaining an
efficient instrument at a mode-
rate cost, he cannot do better
than procure what is ordinarily*
termed a student’s microscope,
which may be obtained from
£3 3s. to £5 5s.

It had long been a desiderata
with microscopists to obtain the
advantage of binocular vision
with stereoscopic effect. Mr. F.

H. Wenham was the successful
adapter of the stereoscopic prin-
ciple to the microscope, which
the following extract from ‘ Re-
creative Science,’ will clearly
explain : —

The result is obtained by the
introduction of a small, but very
accurately formed, double reflect-
ing prism, immediately above the
object glass, so as to intercept
half the rays of light which pass
through it. Fig. 1 will explain
the principle : — a is the body of
an ordinary microscope ; at b a

2

Objects for the Microscope.

square hole is cut, through which the prism c is made
to slide so far that its edge will just reach the central
line of the objective, and should be made to draw back
so as to clear the aperture altogether, when the tube
a acts as a single microscope. When the prism is thrust
in, it collects a portion of the rays, and reflects them to
the opposite side of the tube, where an opening is made
large enough to allow them to pass through, into the sup-
plementary body, e, which in size corresponds to the main
tube ; the remainder of the rays pass uninterruptedly up

Fig. 2 is an enlarged outline of
the prism. Let e e be a ray of light
having passed through the object
glass, and entering the prism at
right angles at the point f ; passing
on, it is intercepted by the surface
A b, which being inclined within the
angle of total reflection, the ray is
towards h, from which point it is
again reflected in the direction re-
quired. If the prism be correctly
made, and of the smallest size pos-
sible for admitting the pencil, the
difference between the direct and
reflected image is scarcely observable;
a faulty prism can therefore be easily
detected.

The adjustment for difference of distance between the
eyes is effected by means of the draw tubes ; if they are at
the utmost limit of proximity when close in, by drawing
them out they can be made to suit every position of eye-
sight. This is very conveniently done by means of a rack
and pinion movement, as shown in Fig. 3.

The opaque principle of illumination should be used in
all cases where possible, as this gives to objects a more
natural appearance. The effect upon looking through a
binocular microscope for the first time is very striking;
many peculiarities are instantly presented to the eye, which,

the principal body.

Fig. 2.

3

Objects for the Microscope.

with a single body, would be observed with difficulty. The
instrument figured is one of those exhibited by Messrs.
Crouch at the Manchester Exhibition of Science and Art.

The advantage of the binocular is chiefly in the rest it
gives the eyes, which have no unequal and unnatural strain.

The field of vision is extended, and objects are seen in
relief, round, life-like, and distinct. The joints of insects
are seen in a wonderful manner, the ball and socket joints
and hinge joints, if well prepared, are now perfectly realised ;
the hairs of plants and animals are seen in their true posi-
tion ; suckers, especially those on the foot of Dvticus,
present themselves in the erect attitude of life, and Diatoms

4

Objects for the Microscope .

mounted dry on a black disc exhibit their form and mark-
ings as if the more elaborate parabolic reflector was beneath.
To testthis, obtain a slide of Heliopelta, or of Isthmia enervis,
or of Arachnoidiscus, which will show the advantage of the
binocular with a very moderate power.

Fossil foraminated Shells (Barbadoes).

Spicules of Gorgonia.

Section of Rush.

Capsules of Moss.

Any of these will answer the same purpose.

Whilst adding a few thoughts to this introductory chap-
ter, let me answer one or two questions not unfrequently
put to me.

How much does this microscope magnify ?

That is, a small binocular with simple eye-piece, and
three object glasses of two-inch, one-inch, and half-inch
focus. The scale of magnifying power varies with different
makers ; but if I give my own microscope as an example,
it will help to make others understood.

The two-inch object glass, which has an angular aperture
of 15°, will magnify twenty-five diameters, or 400 times
superficial measurement.

The one-inch object glass has usually about 33° angular
aperture, magnifies fifty to sixty diameters, or 960 times
superficial measurement.

The half-inch object glass has an angular aperture of 60°
or 65°, and consequently magnifies 120 diameters, or 1,920
times superficial measurement.

Again I am asked, What is the angle of aperture ?

This cannot here be explained beyond the brief state-
ment, that it is the angle made by two lines from' opposite
sides of the aperture of the object glass with the point of the
focus of the lens. A diagram is necessary to make this
quite clear.

The two-inch object glass requires a certain distance, as
at a, to bring the object under examination into distinct-
ness or focus.

The inch, half-inch, quarter-inch glasses, require nearer
and nearer approach to the object for the same purpose.

5

Objects for the Microscope.

The angles so made by the dotted lines are measured by
a graduated semicircle of 180°, under peculiar manage-
ment of light well known by opticians, but beyond our
present enquiry ; and denote the number of extreme lateral
rays which the object glass admits.

The larger the angle the greater is the number of rays
admitted, and the more brilliantly the object is illuminated
the greater, consequently, is the defining power. Experi-
ment has shown that obliquity of light is needful for the
perception of the most delicate markings, and that an out-
line visible with an object glass of small angular aperture
admitting but few oblique rays, as in Fig. 1, would be tilled
up with lines of beauty, and striae of inconceivable delicacy
under an object glass of large aperture, as Fig. 3, which
gives it an oblique illumination.

The markings on butterfly scales and the valves of Dia-
tomacee will illustrate this.

Again, it is asked, What is that particular fault which
object glasses by inferior makers are liable to, called
spherical aberration ? It is when objects at the circum-
ference of the field are not in focus at the same time as those
in the centre, or when part of a single object fades a wav
towards the circumference.

Another fault is chromatic aberration, when coloured
fringes surround the object under examination, whereas an
achromatic lens shows a clear colourless field and a purely
bright object.

6

Objects for the Microscope.

Defining power, not the magnifying power, is the thing
to care for ; we want to see the real structure of an object,
not an exaggerated representation ; and those are the best
glasses which transmit clear light, give a perfectly flat field,
and by which we see sharp distinct lines in the object we
are investigating.

I will but add a few practical hints on the management
of the microscope : —

Do not imagine that an expensive apparatus is necessary.
The greatest discoveries have been made with the simplest
instruments.

Have good object glasses, and do not waste money on
an elaborate stage.

Use low powers in preference to high ones, unless abso-
lutely necessary ; and, remember, we do not want objects
magnified so much as we want them defined. A clearly-
defining low power is the best working glass.

A few simple tools will be sufficient for all purposes of
dissection and examination, viz. —

Slides of glass.

Circles and squares of thin glass.

A pair of forceps.

A lancet.

A few needles, fixed in handles. Split one end of a
match, and tie the needle in with some waxed silk.

Two or three camel-hair pencils.

Six watch glasses.

These are all that are absolutely necessary for daily
study.

FOR MOUNTING OBJECTS.

This need not be a difficult or expensive process ; but to
succeed with insect preparations time and experience are
essential. The easiest beginning is with vegetable speci-
mens— cuticles, pollen, &c. — and with palates which are
mounted in fluid.

You must have a turn-table, price 6s. to 8s., and make
a cell on each glass slide you mean to use, with gold size
or Brunswick black. It is better to see this done than to

Objects for the Microscope.

7

read the best description of “how to do it.” A small
bottle of gold size or Brunswick black costs 6d.

Make a solution of salt and water ; be careful that it is
very clean, and better use distilled or filtered water — five
grains of salt to one ounce of water. This is the best
preservative for palates.

Pure glycerine— a small bottle, Is. This is excellent for
leaves of moss and cuticles ; but they also mount very well
and more easily in Mr. Topping’s liquid : one part of
acetate of alumina to four parts of distilled water.

Let your cells be quite dry ; it is better to make a dozen
or more at once and keep them by you. When required,
fix the slide upon the turn-table, put a drop of the liquid in
the cell with a camel-hair pencil, then lay the object in it.
Have a thin glass cover ready, and let it gently fall over
the cell. Remove the superfluous moisture with a little
sponge or blotting paper ; and then, with a steady hand,
take a brushful of Brunswick black, make the revolving
table run round quickly, and, touching the edge of the
cell, a circle of the varnish will safely fix it. Let the
varnish be thin, and the circle also ; for it dries better,
and there is less danger of its running into the cell-contents.
The next day go over it again, making the circle thicker
and wider.

FOR MOUNTING IN BALSAM.

Have a bottle of clear, pure Canada balsam — it costs Is.

A little spirit of turpentine, 3d.

Spirits of wine, one ounce, Is.

A brass table, or tripod.

A spirit lamp.

Solution of caustic potash.

The use of balsam in preparing insect parts is not only
to preserve, but to show the structure of the object. When
properly applied, it enters into the minutest parts, dis-
placing the air, and rendering the external tegument —
hairs, spines, or suckers — perfectly transparent.

For instance, many young students, anxious to see the
leg of a fly, or of a beetle, clip it off, and put it under the

8

Objects for the ./I ficroscope.

microscope. They are somewhat disappointed at seeing
indistinctly a row of black joints, and nothing more.

Let that leg be first soaked for a few days in a little
potash and water, to soften it and dissolve the internal
substance ; then washed in clean water and dried ; then
soaked for a few minutes in turpentine, and finally mounted
in balsam ; every joint will be clear, every hair visible,
the pulvillus transparent, and the structure admirably
displayed.

The same results are obtained with the eyes, tongues, and
wings of all insects.

The actual mounting is a matter of experience : to keep
out air-bubbles is the great and only difficulty.

Place a slide on the brass table, over the spirit lamp, and
when heated moderately put a drop of balsam in the centre
of it ; let this also become warm, but not very hot, and then
lay the prepared object in it. As bubbles arise, skim them
off with a needle, and take care that the balsam does not
boil, or your specimen is lost ; — it will be full of obstinate
air-bubbles, irrevocably fixed in the tissue. When it looks
clear, examine under the microscope, and if all right replace
it on the table, and having previously warmed a thin glass
cover, let it drop gently over the object.

Dry it on the mantelpiece, or a stone slab, and then clean
the slide by scraping off the balsam and washing it with a
little turpentine ; or soda and water will clean it nicely ;
only if it is left in the solution it will unsettle the balsam.

Try experiments for yourself, and do not be discouraged
by a great many failures ; neither be satisfied with bad
mounting, half-prepared objects, and untidy slides.

PAET I.

OBJECTS FROM THE VEGETABLE KINGDOM.

ie Search out the wisdom of Nature, — there is depth in all her doings.

She hath on a mighty scale a general use for all things ;

Yet hath she specially for each its microscopic purpose.

There is use in the prisoned air that swelleth the pods of the laburnum,
Design in the venomed thorns that sentinel the leaves of a nettle,

A final cause for the aromatic gum that congealeth the moss around a
rose,

A reason for each blade of grass that raiseth its small spine.”

Proverbial Philosophy.

" On every herb on which you tread
Are written words which, rightly read,

Will lead you from earth’s fragrant sod

To hope and holiness and God.” Anon.

CHAPTER I.

In every collection of objects for the microscope we find
many preparations from the vegetable world — slides of
cuticles, fibro-cells, pollen-grains, raphides, &c. &c. ; and
few lose more in being hastily looked at, as merely pretty
objects, without that knowledge of flower-life which alone
can enable us rightly to appreciate them.

If we are wholly ignorant of the structure of plants, their
uses, their variety, and the secret mechanism by which
their life is renewed day by day, we are apt to look at these
slides for mere amusement, for the lust of the eye, pleased
as a child or as a savage with, strange forms or brilliant
colours. Therefore, before we take them up, it will not be
UiiDrofitable to learn if we do not know, and refresh our
memory if we have once known, something of the mysteries
of creation in vegetable life.

1

10

Objects for the Microscope .

Thousands of years have passed away since angel voices
sang the praises of God when He had finished the fair work
of creation, and — looking upon the lowliest herb of the field
as upon the birds of the air, the living creatures of the
deep, wide sea, the beasts of the earth, and man, the lord
of all — “ behold it was very good.” Thousands of years
have passed away : man has changed, it may be that the
lower creatures have partaken of his fall ; but of the beau-
tiful flowers and the stately trees we have no reason to
believe that there is aught in them that offends their
Maker; we fearlessly search into the recesses of their
being, and behold they are wondrously beautiful and still
“ very good.”

A flower-plant has been likened by Unger,* a German
botanist, to “ a most skilfully-planned chemical laboratory,
a most ingenious mechanism for the display of physical
forces, and one of the simplest, and consequently one of the
most sublime, structures ever designed or executed.”

He also likens the growth of a plant to the building of
a glorious edifice ; he compares the cells of vegetable life,
in their varied forms and sizes, to the stones of a building
forming a kind of masonry. In some parts of a plant the
cells are long, and form pipes or cylinders, or they are
condensed and thickened into fibre. In the cuticle of leaf
and flower we have flattened, oblong, or crenellated cells,
which, as a tesselated pavement, protect the more delicate
machinery within.

We find, by the help of a microscope, not only this, but
also the store chambers of cell-contents where the materials
for the plant edifice are collected and preserved.

Again, in the building of a plant there are air-passages
resembling regularly-shaped rooms, or romantic caves, or
microscopic grottos, terminating in what are called stomata;
which stomata have folding doors or valves to open or shut
at pleasure, so that the air circulates freely through the
plant organism. These are mostly on the under side of a
leaf, so the under cuticle is the one we mount for observa-

* ‘Unger’s Letters.*

Objects for the Microscope.

11

tion, and we shall notice these stomata more particularly
when the slides are described.

The origin of every plant is a single cell. The perfection
of a plant, from the tiniest moss to the loftiest oak, is in a
countless multitude of simple cells containing various sub-
stances needful for its growth, and of an infinite variety of
shape and substance : for some cells are very thick ; some
are dotted, to allow of the circulation of air in the deep
recesses of the stem ; some have variegated walls produced
by its secondary deposits, like fibre coiled around, and
these Jibro-cells are abundant in some plants. We have
them from the Oncidium and Opuntia. Some cells of
spiral fibre act as trachea for breathing organs, or give
lightness and elasticity to a stem. They are abundant in
strawberry leaves, vine leaves, rhubarb stems, spinach, and
there are beautiful examples in the slide of spiral cells from
the balsam. Much more can be learnt from the examina-
tion of the fresh plant, because of the difficulty of preserving
cells and their contents. Is it not wonderful to think of a
little plant having its store chambers secreting starch, sugar,
gum, oils, raphides, colouring matter— aye, and beautiful
crystals floating in the cell-fluid, or suspended, as are the
cystolithes, in the cell-chambers of the nettle tribe ?

The very knowledge that such things are, and that they
may be seen in an infinite variety, will lead us first to look
at these slides understandingly, then to seek further by
examination of living plants. This will induce us to study
such books as Quekett’s ‘ Histiology,’ ‘ Carpenter on the
Microscope,’ ‘Mohl on the Vegetable Cell,’ ‘ Schacht on
the Microscope,’ ‘Unger’s Letters,’ &c. &c. Then we
shall see our microscope worthily, and our cabinet of objects
will cease to be a mere toy.

SHAPES OF CELLS.

As the object of this little book is to excite and not to
satisfy the desire of an inquiring mind, let me here suggest
that it is well to prove all things ; and before you quite
believe that every flower and plant is made up of single
cells of varied form, examm^ for yourself thus : — Take a

12

Objects for the Microscope.

flower, a few bits of stalk, a lily leaf, or small piece of
rhubarb stalk, another of cucumber, a thin slice of raw
potato, a wallflower, or a primrose — any flower : macerate
it in water for a day or two, until it begins to decompose,
and the smallest portion placed under the microscope with
a drop of water will show you the now separating cells of
various shape : those in stalks oblong or cylindrical ; those
in the surface of petals and leaves square, or round, or
hexagonal, or irregular, with zigzag boundaries, or papilli-
form, as in the Geranium, Sweetwilliam, &c. ; those of the
parenchyma or pulp of the leaf generally oval. In looking
at these, you will certainly find a variety of contents which
are seldom preserved for any length of time, and which you
must therefore observe in the fresh and living plant.

CELL-CONTENTS.

In the slice of potato you will find every cell crowded
with starch-granules, that is, if it is a good potato ; for starch
is to the potato what fat is to an animal, and if it is in
“ good condition ” the cells should be full of it. The test
of this is a drop of tincture of iodine, which turns the starch-
granules to a beautiful blue or violet colour ; and a diseased
potato with empty cells will therefore be detected by a drop
of that same iodine.

In the stem of a lily you will find starch-grains, mixed
with green granules of chlorophylle, a kind of vegetable
wax, which gives the green colour to leaves.

All our farinaceous plants contain abundance of starch,
especially wheat, barley, oats, maize, rice, arrow-root ; and
the granules differ from each other in size and form so
decidedly, that they cannot well be mistaken by a careful
observer. They are prepared for the microscope, and sold
as polariscope objects, because the examination of a starch
granule with polarized light shows it with a beautiful black
cross, revolving with the polarizer ; or, if over a selenite
stage, a brilliant play of colours is obtained.

Besides starch-grains and chlorophylle, you will find
something else in the cells of that lily stem, which I select
as an easy one to obtain in any garden. In some cells, not

13

Objects for the Microscope.

in all, you will probably observe a larger granule, with a
lesser one within, or perhaps several lesser ones ; the large
granule is the nucleus, the minute inner ones the nucleoli ;
they are the supposed origin of new cells, and much that is
exceedingly interesting has been written in the works before
referred to : ‘Mohl on the Vegetable Cell ; ’ ‘ Hofmeister’s
Die Enstehung des Embryo.’ These nuclei are to be
observed in pollen-grains, in the hairs of Tradescantise, or
Spiderwort, especially in the pollen of the fir-tree tribe.

OIL CELLS.

Cells containing oil are beautiful objects when found as
on rose-trees, on the stem of Saxifrage, Geraniums, Col-
lomia, Drasena, raised upon delicate stalks, often brightly
coloured, or glittering diamond-like in the sunshine.* Some-
times the oil cells are sessile, in golden spots upon the back
of a black-currant leaf ; or white and silvery in the recesses
of a Sage leaf, a leaf of Rue, or Hop, or Mulberry.

Sometimes these oil cells are internal, as in the rind of
an orange, where they are very large and most easily ob-
served ; also in the leaves of Myrtle and Magnolia, of
Hypericum, St. John’s wort, so common in woods and
hedges : those little dark dots are the oil cells, and trans-
parent, if you hold the leaf up against the light, and
examine it with a pocket lens.

HAIRS OF PLANTS.

The hairs of plants will furnish you with abundant ma-
terial for study and delight throughout the summer long,
and the variety in their form will astonish you. Look at
the beautiful bead-like hairs of the Spiderwort — a rich
purple chain of cells fringing each stamen. White, trans-
parent, glittering rows of cells from the flocculent mass of
hairs we see on the leaves and stem of the common
Groundsel. The common garden Verbena has the mouth
of its corolla closed by a dense row of beaded hairs pro-
tecting its pistil. I cannot describe more, but look at these.

These are called glandular hairs.

14

Objects for the Microscope.

Some are simple ; some are branched, or star-like, or
tufted, and contain simply water

Alyssum leaf
Draba verna leaf.
Antirrhinum calyx.
Tradescantia stamen.
Verbena.

Campanula.

Nettle.

Borage.

Chrysophyllum.

Verbascum.

Ivy.

Hibiscus.

Deutzia scabra.
Elseagnus.

Dolichos (cowage).
Groundsel.

Take the hair of a Borage stem or flower off at the base,
and lay it on a slide with a drop of water covered with a
bit of thin glass, and you will be delighted. The hair of
the Nettle, with its poison gland at the base, must be ex-
amined in the same way. The pain is caused by the
breaking off of its point, and the acrid irritating liquid
springing up into the wound.

The reason why these hairs are mentioned immediately
after the cells and cell-contents is, because they are only
prolonged and varied cells rising from the cuticle, and when
the cell-walls thicken into fibre these hairs become thorns.
Sometimes they expand and form scales, as we see on the
beautiful leaves of Hippophie and Elseagnus, which are
mounted as detached scales for the polariscope, or in situ as
opaque objects.

CUTICLE AND STOMATA.

The cuticle of plants is that transparent skin which we
can easily peel off from various leaves, but especially from
the Lily, the Candytuft, Iris, and the petals of flowers ; and
prove by examination under a piece of thin glass and with
a drop of water that it is really composed of a single layer
of cells, having pores, called stomata , thickly scattered
over it.

These slides are very useful to those persons who live
in cities, or who have not yet studied plant-life for them-
selves ; and 1 doubt not that they will lead many a careless

Objects for the Microscope .

15

eye to look for other examples, and to find an endless
variety in the garden and the field.

These pores, called stomata, are absolutely necessary to
vegetable life. Leaves are the organs of respiration — the
lungs of a tree, and the stomach also ; for they send back
nutrition to the trunk and stem, take up the sap which
rises from the root, give it the needful quantity of carbon,
expose it to the action of the air, and cause the super-
abundant moisture to evaporate. All this is done by the
agency of the little dots we call stomata. And this is the
way in which they act : — We see that the cuticle is formed
of a single layer of cells ; these contain air and not fluid,
as do the cells of the pulp or parenchyma ; also they are
so closely fitted to each other as to confine that moisture
which otherwise would be too quickly evaporated by a hot
sun, and the leaf soon dried up and withered ; but at the
same time, as air is necessary to the inner cells of a leaf
or flower, these stomata, or openings, are placed in great
numbers in the cuticle, acting like valves, which admit air
freely, give out surplus fluid, and take in atmospheric
moisture when required. They are bordered by cells of
peculiar form, usually kidney-shaped, with an oval aperture
in the centre ; and these “ guard cells 57 dilate and con-
tract, closing or opening the passage according to the ne-
cessities of the plant. On a hot day they will close, to
defend the inner cells from exhausting heat: in dry
weather, when the stem does not give enough fluid for the
nourishment of the leaves, then the stomata open at night
and drink in the night-dew, but close again as soon as the
cavities of the leaf are full. The number of pores in a
square inch of surface is amazing ; eg. we find that a
square inch of the leaf of

Hydrangea contains
Iris „

Houseleek ,,

Tradescantia ,,

Lilac ,,

Vine „

. 160,000 under surface
, 12,000 both surfaces

10,710 upper surface
2,000 upper surface
. 160,000 under surface
13,000 under surface

16

Objects for the Microscope .

The stomata are generally largest upon succulent plants,
and abound on the under side of all leaves except grasses
and upright leaves, such as the Iris and Tradescantia, where
they are found equally on both sides.

CUTICLE OF YUCCA.

In the cuticle of Yucca the stomata are bounded by four
cells, and are themselves somewhat quadrangular : there are
about 40,000 of them in one square inch. The plant is a
native of Peru ; called also common Adam’s needle, bearing
a handsome flower in panicles on a stem eight or ten feet
high when in its native soil ; but in British gardens it
scarcely reaches three feet high.

CUTICLE OF ALOE.

The cells are somewhat different in shape, though the
stomata are also bordered by four cells : they are more
oblong, very prettily disposed, but require a power of 200
diameters to observe properly. First use the J-inch, and
then the ^-inch.

CUTICLE OF DEUTZIA SCABRA.

This is a polariscope object.

The cuticle is siliceous {see Indian Corn), and the wavy
outlines of the cells and the starry clusters of siliceous
hairs are very beautiful. When gathered from the tree,
these stars are white upon the green cuticle, and those of
the upper surface are many-rayed, whereas those of the
lower surface have usually but four or five rays.

This leads us to consider the use of those abundant hairs
which clothe the living plant. They serve two purposes —
for warmth to the tender bud, or for attracting moisture.
On many plants they rise up towards evening and catch
the falling dew ; then bending downwards at noontide they
form a close layer over the cuticle, and give it a protecting
shade, at the same time preventing a too rapid evaporation
of the moisture they had attracted. There are many
kinds of hairs on plants ; most beautiful are some of them,
especially those which secrete oils or saccharine matter.

IT

Objects for the Microscope.

These are called glandular hairs ; they rise up on a slender
stem, and expand into a globular head, filled with coloured
or white special secretions, such as we find on Sweet-briar
and Moss-rose buds, or on the leaves and flowers of
Collomia.

CUTICLE OF AMARYLLIS.

This example will show the ^o-lobed stomata, one
kidney-shaped cell on each side ; it is from any part of leaf
or stem of the common white Lily ; also compare the cells
with those of the

CUTICLE OF INDIAN CORN.

This is what is called a siliceous cuticle. All the grass
tribe and the plants called Equisetaceae, or horse-tails, have
the property of attracting silex or flint from the soil in
which they grow : the cell walls and stomata become so
impregnated with it, that even soaking in nitric acid, which
destroys the vegetable part, leaves the skeleton, or frame-
work, perfect, as in this slide, which has been thus pre-
pared. Observe the finely-toothed edge of each cell, as
well as the peculiar shape of the four cells bordering the
pores. The stomata are very abundant in grasses ; they
cover every part of the stem, and both sides of the leaves.

CUTICLE OF SACCALOBIUM.

The Saccalobium is one of the orchis tribe, a native of
Asia, found in the Indian Archipelago, and is cultivated
in hot-houses in England. The spiral fibre in some of its
cells forms a regular network on the inner surface.

CUTICLE OF ELA5AGNUS.

This is an opaque object ; the scales are very beautiful,
and when detached from the leaf and mounted in balsam
they polarize.

The Elaeagnus is a native of all parts of the world, from
the northern hemisphere down to the equator, which it
rarely passes. The flowers of this species are highly
fragrant, and abound in honey.

18

Objects for the Microscope .

CUTICLE OF TILLANDSIA.

The under side of the leaves and the stem of this plant
are adorned with delicate scales, as of the finest network.

The plant itself is a native of South America and the
West Indies. The whole tribe dislike water; and Lin-
naeus named the genus from a professor in Sweden, who,
having once experienced a very rough passage from
Stockholm to Abo, determined never again to cross the
water ; he even changed his own name to that of “ Til-
lands, which means on or by land ; and actually, when
obliged to return to Stockholm, preferred travelling 200
miles round by Lapland to going a direct road of eight
miles by sea.

One species of Tillandsia ( utriculata ) which grows upon
old and decaying trees in the forest of Jamaica, has leaves
a yard long, inflated at the base, which form a reservoir for
water. Each leaf holds about a quart of fluid, and wild
cattle seek refreshment there. Travellers also, under the
hottest sun, may turn aside and find a sweet pool of water
in dry seasons, when all other supplies have failed.

CUTICLE OF ONOSMA.

The Onosma is a native of Tauria, near the Bosphorus.
The plant is small, with handsome flowers, flourishing in
sandy soil ; and this cuticle is very beautiful under polarized
light,

CUTICLE OF OPUNTIA.

This beautiful cuticle is from the leaf of the Opuntia, a
kind of Cactus or Indian fig, and on one of them the
cochineal insect is found : this is from the Opuntia vulgaris ,
which bears a large purple juicy fruit, and is a spiny
shrub, growing abundantly on Mount Etna amidst its
lava. It is, however, a native of South America, and the
way in which it has been naturalised and made most useful
in Sicily is remarkable. As soon as a little fissure is per-
ceived in the lava, a small branch or joint of Opuntia is
stuck in ; the latter pushes out roots, which are nourished
by the rain which collects round them, or by Avhatever dust

19

Objects for the Microscope.

or remains of organic matter may have made a little soil.
These roots spread out and ramify into the most minute
crevices, breaking up the lava into small fragments, and
finally rendering it fit for culture.

LITHOSPEKMUM,

From lithos, a stone, sperma, a seed.

The hardy stony seeds have given it this name, as well
as the old English appellative Grom well, from the Celtic
grom, a seed, and mil, a stone.

The leaf of this common plant is extremely beautiful ;
the hairs are not only bulbous as in borage, but cells are
grouped around the base of each like a circlet of crystals.
There are three species worth seeking :

The common white L. arvense, in cornfields.

L. officinalis, pale yellow.

L. purpurea, large blue flowers in chalky soil.

RAPHIDES.

These are crystals found in the cells of various plants.
No better example can we have than the

CUTICLE OF HYACINTH,

in every cell of which we see a cylindrical crystal. Exa-
mined with polarized light they are most distinctly seen,
and enable us to understand the position of raphides in
other plants. The Cactus, the common Dock, and various
other vegetables, have bundles of needle-shaped crystals
in their cells. Turkey Rhubarb and the garden Rhubarb
have rectangular prisms of carbonate of lime grouped in a
stellate form. See the slide of

EAPHIDES FROM RHUBARB.

What their use is we do not know. Another kind called
cystolithes, are stalked and suspended in the cells of the
nettle tribe. Their formation has been watched : first a
little papilla or swelling is perceived at the upper part of a
cell, which increases at the end into a clubbed form, from
which crystals of oxalate of lime sprout forth.

20

Objects for the Microscope.

This is one of the mysteries of creation, how the cells of
a plant so regularly secrete each its appointed store of need-
ful substance for the plant-life — how from the earth in
which it grows, from the air in which it lives, from the light
which quickens it, each tiny chamber receives exactly that
portion of nourishment, and that kind of nourishment
which enables it to produce either the green wax which
colours the leaf, or the white starch-grains, or the gum, the
sugar, the oil, or the shining crystals, or that nucleus which
is the reproductive cell — all this going on invisibly around
us in every living plant, and having been thus going on for
five thousand years at least, unseen, unknown by us, until
the revelations of the microscope. Is there no deep thought
stirred in our hearts by the manifest order and minute
care of Him who built up this living temple for His own
pleasure and for ours ? Do we think of all that is contained
in the flower we gather by the way-side, in the herb that
bends beneath our feet? Is no desire kindled to see these
things as they are, and pass on from these slides to the
examination of the plant itself? There are a thousand
things more beautiful than raphides that cannot thus be
mounted or preserved. Shall I give one example only for
a summer hour’s delight ?

ANAGALLIS.

In the garden or the cornfield gather a little scarlet
Pimpernel, the Anagallis, or the Poor Man’s Weather-
glass, that lowly and bright little flower which opens every
morning at eight minutes past seven, and closes about three
minutes past two in the afternoon. Examine it with a
pocket-lens, and you will see that it belongs to the Primrose
tribe, with its single-leaved calyx and corolla, wheel-shaped,
deeply cleft into fine segments, fine slender filaments and
heart-shaped anthers, one-thread-shaped and clubbed
stigma. With the same lens you can examine the seed-
vessel, a little globular capsule opening all round, and,
raising the lid, observe the most beautiful dotted seeds
lying closely pressed to the pitted receptacle ; and this, if
once seen, will not be forgotten. Take it now to the mi-

Objects for the Microscope.

21

croscope, and, with a low power, first look at one of the
coloured segments of the corolla. Press it lightly in a
drop of water under a bit of glass, and you will then see
that the edge of the petal is fringed with little bell-like
glands, purple and white, and that hues of deeper colour
radiate from the base of the petal. Put on a higher power,
and you will find these are exquisite spiral vessels ; not one
only, but many in each line, short, and joined to each other
by a delicate dove-tailing process. Think of the mechanism
in that one small leaf, and those little oil cells fringing it
so prettily, doubtless for use as well as beauty. Then take
off one stamen and look at it in the same way. Half way
up the slender white stem are purple hairs, each jointed
and like a row of tiny amethysts : above is the heart-
shaped anther, with its golden store of pollen grains, out
of each of which will flow the life-giving germ to the future
seed. Take the style and stigma, and examine them next;
you will not soon be weary of the sight. Most likely you
will find some pollen grains upon the stigma throwing
down their tubes invisibly ; for this is only seen with a
high power, and by making a very thin section of a short
style, such as that of a Cistus, or a Chickweed.

After such an examination, that little flower will never
be seen with the same careless eye which for years had
passed it by unheeded, because unconscious of its beauty.

SPIRAL FIBRE.

Many specimens of these are sold prepared for the
microscope, especially the following

Spiral cells of Oncidium. Spiral cells of Sphagnum.

Spiral vessels of Collomia. Scalariform vessels.

Spiral fibre from Balsam.

They require some little explanation. We have already
seen, in the examination of cuticles and flower-stems, that
plants are made up of cells containing various substances,
as starch, crystals, oil, or wax. These were for the nourish-
ment of the plant ; but here are cells which are supposed

22

Objects for the Microscope .

to assist in the circulation of air and moisture throughout
the system. Some of them strikingly resemble the trachea
of insects, and seem to communicate with the stomata as
the trachea do with the spiracles.

SPIRAL CELLS OF ONCIDIUM.

These beautiful little cells are obtained by macerating the
pulp of those leaves which contain them, separating them
with a fine sable brush, or mounted needle. The Oncidium
is an orchis, a native of Peru, Mexico, and the West In-
dian Islands ; cultivated in hot-houses in England. They
are curious and beautiful plants, with spotted yellow or
purple and white flowers, one species much resembling a
gorgeous butterfly. In all these plants the spiral cells
abound immediately under the cuticle, and, viewed with
polarized light, they resemble coils of coloured wire.

SPIRAL VESSELS OF COLLOMIA.

These fibre-cells are in the cuticle of the seed, and the
examination of them is so easily made, that it is well worth
doing. The cells which contain the fibre are in this in-
stance so delicate, that a drop of water causes them to
break, and the coil unrolls, shooting forth in long tubes,
with an appearance of life as they spring across the field of
sight. To see this, take a seed of Collomia, and cutting off
a very small piece of its skin, place it with a drop of water
on a slide under the thin glass, when you will perceive the
fibre uncoiling in all directions. The Collomia is a native
of America, but naturalised in our gardens, where it grows
like a weed, having pretty buff or pink-coloured flowers,
covered with glandular hairs.

SPIRAL CELLS OF BALSAM.

These are from the common Balsam of our garden, and
show the bundles of long cells made up of spiral fibre,
which often break and pass into annular fibre : you may
perceive some of these in detached rings. These cells con-
tain air, and are those which most resemble the trachea of
insects. Those of the Leek are also very remarkable, and

23

Objects for the Microscope.

the common garden Rhubarb will furnish you with abun-
dant specimens. Take a little boiled Rhubarb, and pick it
to pieces with a mounted needle in a little water, when
bundles of spiral vessels will be easily found.

SPIRAL CELLS OF SPHAGNUM.

Sphagnum is a moss growing in marshy places, and its
leaf shows a beautiful arrangement of spiral fibres in its
large oval cells, whilst in the smaller ones you will see the
granules of chlorophylle which colour the leaf.

SCALARIFORM VESSELS,

so called because they resemble the steps of a ladder, are
peculiar to ferns and to asparagus. They are secondary
deposits on the cell wall, and somewhat of the nature of
spiral fibre. Under polarized light they are very beautiful.

When you pull up a common Bracken or Fern, and cut
the root across, the brown figure you see, called King
Charles in the Oak, is made up of these scalariform vessels.
They are very troublesome to prepare, but this is the easiest
way that I know of: — Cut up the root and boil it until
tender enough to peel ; put the centre part into a jam-
pot with water and a little nitric acid ; let it stand in
boiling water for some hours, then pick the long white
fibres carefully out, wash them in boiling water over and
over again until perfectly clean and clear, which is only
ascertained by examination under the microscope, then
mount them in fluid or balsam. If in balsam, dry them
well first.

POLLEN.

POLLEN OF MALLOW.

A beautiful object viewed as an opaque — more lovely far
when taken fresh from the flower, and looked at upon one

24

Objects for the Microscope .

of its own crimson leaves, or the petal of a Geranium. It
cannot be worthily described : rest not until you have seen
it ; and also the

POLLEN OF HOLLYHOCK,

which is like it, only the golden grains are larger, and per-
haps more easily preserved. I usually take a portion of
the stamen, studded with the spiked globular grains, and
dry them on a scarlet petal of the flower ; but they are
well seen on a black ground, simply mounted, when dry,
between two pieces of glass.

POLLEN OF PASSION-FLOWEK.

These are not spiked, but have three plain valves and a
reticulated cuticle.

POLLEN OF (ENOTHERA

is curiously triangular, with pores at each corner, from one
or more of which the pollen tubes spring forth.

Pollen is always better observed fresh from the plant.
The variety in shape and structure is very great ; the in-
terest will be unfailing in the examination of it, the deeper
we go into the mysteries of plant-life.

This golden dust, which, to the unassisted eye, is all
alike in every flower, is fashioned with the most elaborate
care for its great purpose, and sculptured with that exqui-
site finish which all creation bears as the signature of the
gracious God who made all things well.

This golden dust, contained by every flower in the few
or many stamens which are the caskets of its wealth, is the
fructifying principle which causes the seed to become
fruitful, and without which no reproduction of a plant
could continue, as it does, from age to age.

The purpose of this book being chiefly to explain the
objects before us, I will not say more of the pollen-grain
than that it must be examined both as a transparent object,
with a drop of water or oil of lemon, and dry, as an opaque.
Particularly observe the blue pollen of Epilobium ; the red

Objects for the Microscopi

25

pollen of Verbascum ; the black pollen of the Tulip ; the
varied forms in the following flowers : —

Cucumber

Crocus

Cactus

Cruciferse (order)

Collomia

Campanula

Cobsea Scan dens

Compositse (order)

Geranium

Heath

Daisy (one of the Com-
positae)

London Pride

Saxifrage

Violet

GEnothera

Passion-flower

Lupin

Acacia

A FEW WORDS MORE ON THE POLLEN.

As I lay aside these slides, and desire you to seek for
varieties of pollen in the fresh sweet flowers around, the
thought arises that some who read thus far may wish to
know a little more of the structure of the flower they
gather, and the pollen they examine ; else the microscope
lesson loses half its value, and the student more than half
his pleasure. If it is possible, read some better book —
Linclley’s works, or Balfour’s ‘ Botany/ where all is told,
and illustrated by plates ; but if you cannot do this, then
gather a flower and examine it thus : a Chickweed will be
easily obtained, and is the best for a microscope lesson.

The organs of generation in flowers are the stamens and
the pistil : the stamens varying in number from two to
upwards of twenty ; and the pistil, which occupies the
centre of the flower, having from one to many styles, the
upper part of which is called the stigma. The base of
the pistil, which is swollen and round, is the ovary. Cut it
open with a penknife or lancet, and you will see tiny white
cells on either side, which are the rudiments or beginning
of the future seed. The pollen fructifies each seed whilst
growing in the ovary, and the way in which it is accom-
plished has only of late years been discovered.

The stamens are filaments bearing at the top single or
double caskets, called anthers, full of pollen-grains. When

2

26

Objects for the Microscope.

a flower first opens the anthers are closed all round ; but as
soon as the air and the light have perfected the pistil and
caused it to secrete a kind of gum, or viscid liquid, on the
surface of its stigma, intended to hold fast the pollen-grain,
the anthers open and the golden dust appears, falling on
the ready channel, which conveys it to the ovary beneath.
The pollen-grain itself is not a simple cell, as we might at
first suppose : minute as it is there are many cells therein,
and a subtle fluid, called fovilla, which is in reality the life-
giving principle to the ovule. When a pollen-grain falls
upon the stigma it presently opens one of its pores, and
sends forth a tube more or less long, which descends
through the tissues of the style, enters the ovary, reaches
a tiny ovule, and pours it into the fovilla, which fovilla
forms the embryo or future plant that is preserved and
nourished in the seed.

Take a little pollen from a Cucumber plant or Passion-
flower, and when it is fairly under the microscope, covered
with thin glass, let a drop of water run in. The moisture
is absorbed by the pollen-grain, and it throws out a tube
and discharges the fovilla. It goes off like a little cannon,
a cloud of fovilla waving on the slide.

The quantity of pollen in a flower is astonishing. A
flower of the Peony, for instance, has about 174 stamina,
each containing 21,000 granules, — total, 3,654,000 pollen-
grains. A single Dandelion has 243,000 pollen-grains.
The contents of one anther are quite sufficient for the fruc-
tification of all the ovules ; but the superabundance is not
wasted, for thousands of insects live on the golden store,
and the busy bee fills her baskets hourly with these pretty
cakes for her nurslings.

POLLEN-TUBES.

To see the actual pollen-tubes in their passage down the
style is a more difficult matter ; nevertheless, with care and
a good glass it may be managed. Put on the J-inch and
choose a flower with a very stout style, — a Cistus or this
Chickweed ; the flower must have just faded , then you may
be sure the ovules are fructified. With a sharp razor make

Objects for the Microscope.

27

a very thin section of the pistil, and lift it with a fine sable
brush on to a slide in a drop of water, and cover as usual
with thin glass ; focus carefully, have good light, and you
will see the pollen-tubes actually descending the tissue of
the style.

Now we are considering a great mystery. We see how
varied are the lengths of styles and pistils, yet shorter or
longer the pollen-tube stops not until it reaches the ovary,
and when there, amidst the many rows of ovules, in many
positions, it has to seek the one spot in each ovule by
which alone it can enter, and there, and there only, it rests.
Perhaps all but one have been fertilised, and are closed — it
seeks that one and perfects the work. Thus we see the
all-directing, all-sustaining, life-giving power of the Omni-
present one ; we see His presence in the tiniest flower. He
alone knoweth how this may be, — we only see that it is so ;
and reverently let us ever search into the mysteries of crea-
tion, and find new and deep delight in these revelations of
His secret order, wisdom, and care for the preservation
even of the flower of the field.

STAMENS.

The shapes of stamens are also to be noticed. Some
open lengthwise, some across ; some have valves like fold-
ing doors, flying upward, as in the laurel tribe. The
anthers of the barberry are on jointed filaments, which are
exceedingly irritable, and, if touched by the smallest insect,
spring up and scatter the pollen on the pistil.

Euphorbia, or spurge, — a common weed in every garden,
— has a pistil which hangs outward and downward, appa-
rently out of reach of the pollen. The anthers rise up and
shoot it out like little guns, one after the other, at the
stigma of the flower.

Nettles also have beautiful elastic filaments for scattering
the pollen on the pistil, which is in a separate flower.
Many plants have these organs thus separated, but pro-
vision is ever made for their union, as in the case of our
cucumbers, where bees and flies carry the pollen from one
flower to the other.

28

Objects for the Microscope .

SEEDS.

Having said a little on the beginning of the seed in the
ovary, we shall be prepared to look at the seeds themselves
with greater interest. Here also we have an endless variety
of beautiful microscopic objects : —

POPPY SEEDS,

viewed as opaque objects, show a reticulated surface ;

SWEET-WILLIAM SEEDS,

oblong and dotted ;

SILENE, OR STELLARIA,

beautifully fretted and sculptured —

Portulaca
Passion-flower
Begonia
Scropularia
Hyoscyamus.

Look at all these ; and, above all, get a prepared slide
of the exquisite

ORCHIS SEEDS.

Foxglove

St. John’s Wort

Saxifrage

Geranium

Anagallis

They are like little net-purses, with the seed in them : the
loose net is the skin or cuticle of the seed.

ECCREMOCARPUS OR CALAMPELIS SEED.

This winged seed is a splendid object for the polariscope.
The Eccremocarpus, a beautiful creeper, with large bright-
coloured, trumpet-shaped flowers, is a native of the tropics.

SEED OF CENTAUREA CYAN US.

The section of the seed of this plant is an excellent object
for the binocular. It is common in corn-fields, with small
purple florets of the disk, and large bright-blue florets of
the ray. Named from the centaur Chiron, who was said
to have cured himself of a wound in the foot with the leaves
of this plant.

Objects for the Microscope .

29

CHAPTER II.

SECTIONS OF WOOD.

The use of these sections is to show the structure of the
stem of plants, and the difference between the two great
divisions of the vegetable world into endogens and exogens.
An endogen is a plant which has long straight-veined leaves
like a Palm, a Cane, a Lily, Iris, Daffodil, and all the
grasses. The flowers are usually divided into three, or a
multiple of three ; the embryo has only one seed-lobe, or
cotyledon, and the stem is like the section of

RUSCUS,

or Butcher ’s-broom, a common shrub in waste and watery
places, with very rigid dark-green leaves, tipped by a sharp
spine : it blossoms in April, but is chiefly admired for its
large scarlet autumn berries, one in the axil of each leaf.
This pretty section — apparently a fine lace-pattern — shows
the structure of an endogenous tree ; it grows from within,
and is composed of a dense mass of simple cells, in the
midst of which, in varied patterns, run upwards bundles of
denser cells called “ fibro-vascular” ; and each bundle has
one or more ducts, best seen perhaps in a section of

WANGHAE CANE.

Sometimes the centre cells disappear and leave the stem
hollow, as in the grasses and many of the water plants.
Compare now this slide, and also a section of

ASPARAGUS,

with that of the Hazel or Apple.

SECTION OE HAZEL.

Here we see very distinct organization on quite a different
plan. The exogen has veined and reticulated leaves ; the

30

Objects for the Microscope.

seeds have two lobes, or cotyledons ; the flowers are
arranged in four or five. The wood grows by the addition
of cells, in circles, to the exterior of that last formed, and
we see distinctly the open cells of the pith in the centre ;
the medullary rays running from the centre to the bark at
intervals, with sap-vessels and cellular tissue in circles, as
they were added on.

CEDAR OF LEBANON,

a firm, dense wood ; the cells are very minute, the circles
very distinct ; each circle is a year’s growth, and the medul-
lary rays are very fine and numerous, radiating from the
centre. Those dark bands forming the circles are made up
of vascular tissue, or woody fibre, composed of long pointed
cells, which overlap one another, and deposit internally a
strengthening wall of a substance called scleragen, which is
most abundant where not only density but great power of
resistance is required. When young these woody fibres
conduct the sap with facility through both stem and
branches, especially of the fir tribe ; but after they are
thickened they only afford support, and become what car-
penters call u heart-wood.” The sap-vessels of trees are
those nearest to the bark, which makes the barking of trees
so dangerous to their life.

SECTION OF PINE.

Look next at this section, because it shows some pecu-
liar dots on that same woody fibre, called glandular dots,
and which are remarkable as belonging to that tribe, and
also at one of the yew tree (Taxus).

SECTION OF TEW.

In this section, if vertical, there is a beautiful com-
bination of spinal fibre with coniferous pits.

These pitted structures require explanation, especially as
those of the pine or common deal are used as tests of the
defining power of the object-glass. The pits in coniferous
wood are surrounded by a broad rim.

The origin of the pitted cell is in the unequal deposit of

31

Objects for the Microscope.

secondary matter inside the cell-wall. Always remembering
that a young cell is a simple sac of a single membrane,
which, containing a certain fluid, is capable of secreting
various substances, curiously separated from, or combined
with, the various gases and inorganic matter which form
the soil in which it grows. These secretions are used for
strengthening the cell-walls, as the young plant springs
upward ; therefore, if the deposit inside the cell is uneven,
it causes marks on the cell-wall ; if the cell grows faster
than the supply of deposit, the markings are spiral or
arched, or waved, or dotted ; and these are best observed
by comparing different cells from fresh plants. The anther
of the vegetable marrow, if peeled and then examined with
a drop of water, will give beautiful cells of arched fibre.
But, to continue with this slide, — these pits are at first only
dots in the secondary deposit ; then as the cell thickens
these pits deepen, the primary membrane breaks, and they
become channels from cell to cell, as you may see in a sec-
tion of vegetable ivory, where you perceive radiations from
each cell, which are, in fact, these deep pits, and in a vertical
section would look like the pitted cells of Fir, or Clematis,
or Lime-wood, or Laurus sassafras , and many others.

VEGETABLE IVORY.

Vegetable ivory is the seed of a palm called Phytelephas
macrocarpa , and is composed of a large round mass of bony
albumen, in which a small embryo is imbedded. Slices of
this ivory -like albumen, placed under the microscope,
afford very beautiful examples of these thickened cells.

FOSSIL CONIFEROUS WOOD.

Fossil coniferous wood, which is wood converted into
lignite, or a kind of coal, when the vegetable matter is
almost entirely removed and replaced by silex (flint), pre-
serving all the peculiarities of structure. This fossil wood,
from Tasmania, will show the pitted ducts, which prove it
to be one of the Coniferse, or family of firs.

32 Objects for the Microscope .

Always add to your collection sections of

FOSSIL PINE WOOD,

vertical, horizontal, and tangential.

SECTION OF COCOA NUT.

This gives an example of cells thickened into very con-
solidated woody tissue.

SECTION OF COB NUT.

The cob nut, or hog nut, is the seed of a plant (Omphalea),
belonging to the natural order of Euphorbiacese, native of
Jamaica.

SECTION OF SNAKE WOOD.

This is the wood of a plant called Ophioxylon,* from its
twisted root and stem, resembling a serpent. It is found
in the East Indies, sometimes as a climbing plant, bearing
bright red and white flowers ; sometimes as a small shrub,
the root of which is a famous nostrum with the native
physicians.

MOSS.

SLIDES OF DICRANUM, FUNARIA, ETC. ETC.

There is no season without its beautiful symbols of
God’s power and love, His wisdom and forethought. Spring
flowers fade away ; the summer foliage withers and falls
from the trees ; the autumn soon loses its crown and the
last of its flowers ; but hardly have the lingering Dandelion
and little Daisy left us than on every old wall and knotted
trunk we And, in rich profusion and variety, the capsules or
seed-vessels of the pretty mosses.

They are our little way-side friends, — we often gather
their trailing stems and leafy sprigs ; but few persons, com-
paratively speaking, pause to examine their exquisite seed-
vessels ; therefore a few mounted specimens will be of great
value in the collection for our microscope.

* Opliioxylon, from i '<pis, a serpent, and |uAor, wood ; because it has a
twisted root and stem.

Wings of Insects.

Plate 4.

1. Wing of Earwig, shewing its method of folding up.

2. Wing of Earwig, magnified 4 diameters. 3. Earwig flying, natural size.

4. Wing of Whirligig-beetle," magnified 5 diameters. 5. The same natural size.

6. Minute portion of Beetle’s wing, magnified 420 diameters. 7. Wasp’s wing, folded.
8. Wasp’s wings, hooked together, magnified 3 diameters.

9. Hooks on Wasp’s wing, magnified 60 diameters.

33

Objects for the Microscope.

Before I describe the growth of a moss or the slides
before us, it is necessary to learn the several parts of its
fructification, and, if possible, to procure specimens of each
of them.

A moss is a flowerless plant ; the fruit or seed-vessel is
the only visible organ of reproduction, and consists of —

The capsule, or urn-like body, which contains the spores.

The operculum, or lid of the capsule, which shuts in the
spores until they require light and air.

The calyptra, or veil, which protects the young capsule.

The peristome of the capsule, which in most of the mosses
is set round with a single or double row of teeth, such as
you see in Dicranum or Bryum, and which are curiously
regular in their number, varying from four to sixty-four,
but always a multiple of four. Remark this in any you
may examine ; there will be four or eight, sixteen or thirty-
two, and one variety (Polytrichum) has sixty-four ; but
there will be no odd number.

The inner peristome,, or cilia, a fringe of delicate inner
teeth, often rising like a cone in the centre of the capsule,
pale yellow, or pure white, whereas the outer row is usually
crimson or brown.

The columella is a column in the middle of the capsule,
round which the spores cluster, and which you will only see
by carefully dividing an unripe capsule lengthwise, making
a thin section, and looking at it with a drop of water under
a low power, when it will delight you.

The growth of a little moss is so interesting that we shall
do well to watch it in our winter walks, from November to
April.

Botanists are not yet quite agreed about the green
filaments, which are the first appearance of fructification,
and whose different cells contain the germs of the future
moss. They are called antheridia and pistillidia, analogous
to the stamens and pistils of a flower, but very different
in their structure and action. Read the chapter on the
structure and reproduction of moss in ‘ Carpenter on the
Microscope or, better still, read Hooker and Taylor’s
‘ Muscologia Britannica.’

34

Objects for the Microscope.

The part that we can daily observe with a simple pocket
lens is this: — The little capsule rises from its mossy stem
wrapped in a delicate leaf, which breaks from its stalk,
and is carried upwards in the growth of the tender bud it
is to protect from the winter cold. This leaf forms the
calyptra before described, and varies in colour, form, and
substance : on some species of moss it is quite transparent,
of bright green or pale yellow ; on some it is hairy and
thick. By-and-by the calyptra falls off, — splits up the
side, or comes off whole, — and then the capsule is seen,
wholly formed, but closed by its lid or operculum. This
also varies much in form and colour ; sometimes, as in
the tiny Weissia on stone walls, it is bright apple-green,
tipped with scarlet or crimson, very beautiful to look upon
even thus ; but none could guess at the exceeding loveliness
concealed beneath this pretty lid, nor without a microscope
could we see further into its mysteries.

If we take an unripe moss and divide it, we perceive the
spores clustering round the columella, and growing in
warmth and security within the closed capsule. But an
appointed time conies, and then the operculum opens, falls
back, and we see the peristome surrounded with a double
or single row of teeth, — four, sixteen, thirty-two, or sixty-
four, always an even number and multiple of four, as I
have before observed, — the outer row rich crimson or brown,
and the inner cilia pure white or pale yellow, forming an
exquisite network as they bend protectingly over the
mouth of the capsule, allowing the imprisoned spores both
light and air, yet saving them from cold and wet and tiny
insects, until they are perfected and ripe for dispersion.
When their work is accomplished the cilia open, the little
teeth unclose, and the spores fall to the ground, or are
borne upon the winds hither and thither, to vegetate
wheresoever it pleaseth God that they shall grow. All
this care hath He taken of the spores of a tiny moss !
Yes ; and these mosses occupy no unimportant position
in the economy of nature. They are, with lichens and
fungi, called servi, or servants, because they are the earliest
forms of vegetable life, and prepare the soil for higher

35

Objects for the Microscope .

plants. In ttie most desolate regions, in the coldest
climate, the little moss is found. This very Dicranum, at
least its species Dicranum bryoides , was once the friend of
the great traveller, Mungo Park. He was bewildered in
a desert, and, over-weary even unto death, had laid
himself down despairingly to die. As he did so, a little
Dicranum caught his eye ; the sight of its beauty touched
him, the thought of God’s care for it awakened the better
thought of — “ If God so cares for the grass of the field,
which to-day is and to-morrow is not, does He not much
more care for me ? ” He rose up, tried once more to find
his way, and was saved.

Mosses abound everywhere ; they fill even the rank bogs,
and form rich mould for the aristocrats of creation ; they
cluster round the wild flowers, and protect them in their
•earliest state from cold and injury. Servants of creation,
servants of God, they fill their appointed place, and do
their Maker’s will, beautiful in their lowliness as the state-
liest oak of the forest.

THE DICRANUM

is found from November to April, in hedges or clay banks.

FUNARIA HYGROMETRICA

is to be viewed as an opaque object. The crimson peri-
stome of twisted teeth and the white cilia gathered into a
silvery knob in the centre is one of the loveliest objects we
can look at. They are best gathered fresh, and all the
winter long we find them on walls and in hedges, or waste
places, especially wherever wood has been burnt, or near
railway stations.

The leaves of mosses are made up of cellular tissue, and
in a young leaf of Fun aria we see the chlorophyll-grains
very distinctly. They want no preparation beyond placing
under thin glass with a drop of water.

The capsules of Dicranum and Weissia are better
mounted in balsam ; and Funaria is best seen when simply
gummed on a circle of black paper, and protected by a
cell of cardboard and thin glass.

36 Objects for the Microscope.

There are upwards of forty genera and a thousand
species of moss, of which 39 genera and 400 species are
found in Great Britain.

SPORE-CASES OF FERN.

The fructification of ferns affords a great variety of
microscopic objects, though we rarely find any but the
spore-cases of the common Polypodium mounted in this
way ; therefore, after looking at the slide, we should by
all means collect and examine as many varieties of fern as
we can, not only for the shape of the thecae, as these little
cases are called, but for their position on the frond.

This Polypodium is a most common fern, growing upon
old walls and hedgerows, and the round yellow spots on
the underside of the frond are masses of these spore-cases
called sori.

Observe that each theca is clasped by an elastic ring or
band, called the annulus, and the spores are kept safely
during their growdh, as in a golden casket ; but, as soon as
they are fit for dispersion, the membrane which encloses
them breaks, and the elastic band is seen with an empty
little cup at each end. The spores themselves resemble
pollen-grains, and are very prettily marked ; but will
require a higher power, and had better be examined from
a fresh frond, with a drop of water, or a drop of oil of
lemon, which is an excellent assistant in the observation of
pollen and spores of all kinds.

The great profusion of these organs of reproduction is
astonishing. If we take a leaf or frond of the common
Hart’s-tongue ( Scolopendrium ), and count those brown
lines on the underside, which are the sori, we find at least
fifty in a good-sized frond ; in each sorus 4,000 of these
tiny thecse, sometimes 6,000; and the thecse themselves
enclose about fifty spores : thus we shall find that a single
leaf of the plant may give rise to no fewer than ten
millions of young ferns.

An interesting experiment may be made to learn the
growth of a fern, by simply shaking some ripe spores on
a saucerful of fine mould, covering it with a bell-glass or

Specimens of Hair, magnified 200 diameters.

Plate 7.

1. Wool.

2. Hair of Horse.

3. Human Hair.

37

Objects jor the Microscope.

tumbler, and keeping it moist, warm, and shaded. In a
short time a thin green film will spread over the soil, which
take up carefully on the point of a lancet, and examine
under the microscope. The little spore first becomes
swollen, angular, and bursts, throwing out a fine rootlet,
which fixes in the soil and draws in nourishment. Then a
number of delicate transparent cells are formed from the
mother-cell in the spore, making a little green scale, which
as it expands throws out many fibres or rootlets on the
underside. The wonderful part is that this tiny green
scale produces two kinds of cells, which fructify each other,
as do the stamens and pistil of flowering plants.

One set of cells, called antheridia, contain most curious
spiral filaments, which move spontaneously, and wheel
round and round until the cell breaks, and they escape
to enter into the other kind of cells, called archegonia , or
germ-cells, from which the real stem of the future fern is
produced. This is difficult to watch, and it requires a
power of 300 diameters to see these moving filaments,
called antherozoides ; but the development of the little fern
is m itself worth seeing and mounting for the microscope
in its several stages.

Ferns are amongst the flowerless plants, — very numerous,
very useful ; not fewer than 2,000 species inhabit various
parts of the world, from the tall Tree-fern of the tropics,
more than fifty feet high, to the humble Spleenwort
(Asplenium ruta-muraria) which haunts our ruined walls.
Their claim to usefulness rests on their medicinal pro-
perties ; the thick mucilage from Adiantum capillus Veneris
being a famous cough nostrum ; a decoction of Polypo-
dium is taken as an anti-rheumatic and sudorific beverage ;
Osmunda regalis is given to rickety children as a tonic ;
and others are used as styptics and purgatives. The roots,
when roasted and peeled, are eaten by the natives of New
Zealand as we eat bread.

Shirley Hibberd’s ‘ The Fern Garden ’ is a most useful
companion in a country walk, to assist us in recognising
the different species.

38

Objects for the Microscope.

ELATERS OF EQUISETUM.

This slide is useful chiefly in directing attention to the
plant from which the elaters are taken, and as leading the
student to an interesting experiment.

The Equisetacese, or Horsetails, are leafless plants found
on moist ground, in ditches and rivers, with whorls of long
slender branches, and a hollow stem which gives the micro-
scopist a very beautiful siliceous cuticle with stomata. The
fructification is found in the spring : a fertile scaly head
rises from the earth, having circles round it of shield-like
discs, beneath which the spore-cases and these spores, which
then appear only as a fine green dust, lie concealed.

Shake a little of the dust on a slide of glass, and innu-
merable small bodies will be seen, each with four elastic
filaments clasping and unclasping them in quick motion for
several minutes. If dry and motionless, by lightly breathing
on them the action will be repeated. These are the elaters
of the Equisetum, and the mechanism by which the spores
are dispersed.

ELATERS OF JUNGERMANNIA.

Jungermannia, or Scale-moss, is a plant of lower rank in
the vegetable world than the true moss, such as Dicranum
or Funaria. The elaters which are here mounted belong
to that species called Jungermannia dilatata, which creeps
over the bark of trees, and tints the trunk of an old elm or
oak with a rich brown or crimson ; here and there a patch
of this scaly plant encrusting the rugged surface, and
requiring the aid of a pocket lens to see its fructification.

Any time from November to March look closely at one
of these dark masses, and you will see dotted over it tiny
globes, white as of frosted silver, rising on a slender stem,
and perhaps great numbers of exceedingly minute fawn-
coloured flowers. If you gather one and examine it with
a good glass, small tufts of spiral fibre will be seen on each
segment of what seems to be a flower — these are the elaters.

o

Now this is not a flower, but a simple spore-case. The
little white globe before noticed splits into four valves, and
these elaters of spiral fibre uncoil with a spring and scatter

39

Objects for the Microscope.

the ripe spores. There are seventy species of British
Jungermannia, which have been admirably described and
delineated by Sir William Hooker. We can find several
of them in our country walks anywhere, and the leaves of
cellular tissue are particularly worthy of observation under
the microscope.

JUNGERMANNIA BIDENTATA.

This is an example of the delicate toothed leaves of one
species. We find another, Jungermannia furcata, very
commonly on the same tree as J. dilatata ; it has a narrow
green frond, forked at the extremity, and on the underside
we may see the anthers, or antheridia, the male organs of
the plant. They are small green globules, which cannot
be properly observed without a microscope.

The elaters are best seen wThen mounted in balsam ; the
leaves either dry or in glycerine.

FUNGI.

SLIDE OF PUCCINIA, OR PHRAGMIDIUM.

Before we appreciate this apparently simple object, it is
needful to learn something of the vast extent and variety
of the family to which it belongs ; but the limits of this
catalogue will not allow of more than a very brief state-
ment of necessary infarmation.

The Fungi are plants of low organization, of which the
highest in rank is the common Mushroom, the lowest that
fine mould or tiny spot which we find on dead leaves or
decaying wood, or as a film upon our preserves, or a tiny
forest on our stale paste. Everywhere, in short, we may
gather specimens of Fungi, and find beautiful life in death
under the revealing power of our microscope.

Few of them are at present mounted for the student,
but this species may always be obtained ; it is a fungus
parasitic on the Rose-tree.

The Puccinia is a mildew which infests the straw of
Wheat, the leaves of Roses, Blackberry, Potentilla, Box,
and Ground-ivy. We merely see small black spots, usually

40

Objects for the Microscope.

surrounded by a circle of orange- coloured cells, which if we
scrape off and soak for a minute either in turpentine or
diluted nitric acid, each particle of black dust (for it appears
nothing more to the naked eye) is found to be a pear-
shaped seed-vessel, divided into compartments containing
spores. This Puccinia of the Rose or Blackberry has from
five to seven compartments, or spore-chambers, and is the
best specimen to collect for observation. Some botanists
call it Phragmidium, and Aregma.

If you wish to see the actual escape of the spore, scrape
the fungus from the leaf, and let it soak in a little alcohol
on the slide to disperse the air. Before the spirit has quite
evaporated, add a drop of nitric acid under the thin glass
cover, and warm it over a spirit-lamp, press the glass gently,
and in all probability the inner cell of the spore-case will
come out, enclosing the spore itself.

To see the germination of Puccinia, you have only to
scatter some of these spore-cases in the spring on some
moist flannel, or on a floating piece of cork, when they will
presently throw out long colourless filaments, at the end of
which three or four septa will be seen filled with orange-
coloured endochrome or pulp of granular matter ; then a
spicule will rise on each septum, and expand into a globular
head, into which the orange-coloured matter will pass, and
these eventually fall off and begin to germinate on their
own account.

The spores of fungi, being light and excessively minute,
float in the air, enter plants through the stomata, and ger-
minate in the cell beneath.

BLIGHT OF WHEAT (SMUT).

This is a fungus of globular form, black and powdery,
covering the young ears of corn like a coating of soot. It
is called Uredo segetum. The spores are so exceedingly
minute, that upwards of seven millions eight hundred and
forty thousand of them would be required to cover a square
inch of surface.

UREDO FCETIDA OR BUNT,

is another species, also bl ghting the wheat, but found in
the grain, which looks dark, though otherwise like the sound

... .(Wlltlll

Scales of Moths and Butterflies.

Plate 6.

1. Wing of Herald Moth. 2. Spot on Herald Moth’s wing, magnified 60 diameters.
3. Eye-like spot on wing of Emperor Moth. 4. Part of Eye-like spot, magd. 60 diams.

5. Scales of Underwing Moth, magnified 80 diameters.

7 . Brimstone Butterfly. 8. Scales of Brimstone Butterfly, magnified 150 diameters.

9. Scales of B,ed Admiral Butterfly, magnified 100 diameters. 10. Scale, magd. 150 diams.

Objects for the Microscope.

41

wheat, until it is crushed, when a fetid black powder is
seen, the spores of which are larger than those of the smut.
Nevertheless, each grain contains four millions of them.
They are of an oily nature, so that they stick to the
healthy grains, and, if sown with them, infect the next
crop ; therefore farmers dress their wheat with potash to
destroy this fungus.

UREDO, OR yECIDIUM.

I mention this, although few specimens are mounted,
because it is met with abundantly throughout the autumn
and winter on the underside of the Coltsfoot leaf, on Spurge
in our gardens, on the twigs of Fir-trees, and on almost
every garden vegetable. These yellow spots on leaf or stem
are beautiful microscopic objects. The orange-coloured
spores form under the cuticle, which breaks sometimes like
a cup, or coronet, full of golden dust, that is most interest-
ing to the observer.

I will only add that there are 4,000 species of fungi, most
of which are parasitic on plants and animals. The human
body is also subject to their growth — the internal parts, as
well as the bulb of the hair, the tongue and palate. The
tartar of our teeth is partly a fungus, and so is the thrush
in infants.

We can find a rich store of curious and beautiful forms
on every dying leaf or decaying stem. Examine the mould
on paste or jam ; the Puccinia on Rose-trees, Beans, Black-
berries ; the .ZEcidium, growing in bright-red spots, on
Gooseberry and Barberry leaves in June and July; also on
the white film on leaves of the garden pea. HCcidium is
called erysiphe, and has little spore-cases dotted over it.
So also on the leaves of the willow, a lovely little erysiphe ,
each black dot fringed with hooked filaments. These will
give some idea of the variety of fungi, and their invisible
and unknown beauty. Look over Greville?s work on the
Cryptogamia, and Mrs. Hussey on the Fungi; or get at
Bulliard’s fine old book on Microscopic Fungi, when your
winter walks will abound with hitherto undreamt-of objects
of delight.

3

42

Objects for the Microscope .

CHAPTER III.

INFUSORIAL EARTHS.

These slides, which require high power and a good
microscope to examine, consist of specimens of Diatomacese
from different parts of the world. Their value is in pro-
portion to the knowledge of their possessor concerning the
Diatomacese generally and particularly. The Diatomacese
are minute vegetable forms, called also “ brittle worts,”
from the almost unavoidable separation of their cells or
frustules in handling them. Long have they caused dis-
putes as to their animal or vegetable nature. Very eminent
naturalists, such as Ehrenberg, seeing them gifted with
spontaneous motion, — the little golden Naviculee sailing
slowly across the field of vision, apparently turning back
when meeting with an obstacle, or whirling gently round
as if by their own will, — decided that they were surely
animal, and classed them with the Infusoria, which are
microscopic animals , found in salt and fresh water. But
later researches and patient investigation have placed
beyond doubt the vegetable nature of these beautiful crea-
tions, to whose variety there appears no limit.

As the wondering astronomer discovers the infinite
worlds revealed in unfathomed space, and sees star after
star arise in countless myriads within the dim and distant
nebulae, — as his mind bows down overwhelmed by the sense
of the omnipotent Creator’s dominion and guidance of all
those glorious orbs, — even so the microscopist bends in
astonished awe before the infinitude of God’s works in the
uncountable varieties and exquisite beauty of the minute
Diatoms.

Bilin Slate. — Wherefore are they thus highly wrought,
and why in such abundance ? Take up that slide of Bilin
slate, and know that in one single cubic inch 40,000 millions
of these delicate forms are found !

43

Objects for the Microscope.

Richmond. — Look at the earth from Richmond — it is
a very small quantity of a marine deposit — eighteen feet
deep, underlying the whole city of Richmond, U.S., and
extending over an area whose limits are not known.

Algieks, Okan. — Observe the beautiful discs in that
slide of earth from Algiers. Use the highest power that
the art of man has yet constructed, and hardly will you see
all the beauty which the finger of our God has traced on the
circular valves of these little Diatoms, called Coscinodiscus,
Actinocyclus, Arachnoidiscus, or Heliopelta. These names
sound hard and perplexing to beginners, but they are full
of meaning to any one acquainted with Greek ; and there is
this great advantage in such nomenclature — that it is un-
derstood alike by scholars of all nations. The difficulty of
scientific names lies not in the names themselves, so much as
in our deficient education, which wastes the time and the
intellect of young ladies in acquiring accomplishments and
modern languages without the solid foundation of Latin
and Greek, which is acknowledged to be essential for men.
These discs, and some others most commonly mounted as
objects for the microscope, will be explained presently ;
it is necessary previously to say somewhat more of the
Diatom acese generally.

And, first: They are now decidedly placed in the vege-
table kingdom. They are found to consist of simple cells,
whose membrane is so thoroughly impregnated with silex
(flint) that it is indestructible by those powerful acids or by
such heat as would totally destroy a simple cell-membrane.
They consist always of two valves united at the edges, like
a bivalve shell, and containing endochrome, like the plant-
cell ; sometimes oil-globules, and a granular substance
which has been seen to circulate within. For a proper
understanding of this read ‘ Carpenter on the Microscope ’ ;

( * Smith on British Diatomacese ’ ; ‘ Pritchard’s Infusoria 9 ;

; ‘ Annals of Natural History,’ 1843 and 1848 ; ‘ Microscopic
Journal,’ 1854.

The markings upon the valves, and their shape and
position, are the distinguishing characters which decide the
species.

44

Objects for the Microscope.

They are found in the living state abundantly in every
pond and ditch, ocean and rock-pool. They are in immense
deposits in every part of the world. A mud-bank, 400
miles long and 120 broad, has been found on the flanks of
Victoria Land, wholly composed of these siliceous valves, or
loricse. In Sweden and Norway they are used under the
name of bergli-mehl , and mixed with the flour for bread. In
the masses of guano these imperishable Diatoms are found in
profusion, having been eaten by shell-fish, re-swallowed by
the sea-bird, and passed through its digestive organs, to
reappear unharmed, in all their beauty, as you may see
them on the slides sold as “ discs from guano.”

DIATOMS OF GUANO.

It is not possible to catalogue the contents of the slides
sold as infusorial earths from various parts, because every
slide has a different collection, and the student should care-
fully study each slide, and learn its contents, with the help
of such a book as ‘ Pritchard’s Infusoria.’

The earths from the following places contain some of the
most beautiful forms

Algiers

Mull

Bilin

Italy

Barbadoes
Auvergne
Richmond (discs)
Bangor, U.S.
New Durham

Kieselguhr

Lapland

Gossa

Obero

Habitchtswald
Tullamore
Lock Mourne
Premnay
Wreatham, U.S.

Virginia (discs)

Piscataway

Manchester, U.S.

Rappanhanna

Schockhoe

Rugen

Slieve Mor Hills
Bermuda (discs)

NAVICULiE.

Some Diatomaceae, however, are mounted separately,
either as test-objects, for their delicate striae, or for their
peculiar markings ; and none more frequently so than the
Naviculae, of which Navicula hippocampa} or Pleurosigma
angulatum , are favourite examples.

Objects for the Microscope.

45

NAVICULA HIPPOCAMPA.

The Naviculse comprise the largest section of the whole
body of diatoms, and vary very much in form and markings,
but the genus Naviculse itself is so called from its resem-
blance to a boat or little ship (Nave, a ship). They are
found, both in the living and fossil state, of a bright golden
colour, the valves delicately striated, with or without a
central aperture. Some are striped longitudinally ; some
transversely ; some waved or shaped like the letter S, as

PLEUROSIGMA,

in which the apparent strise are resolvable into hexagonal
dots under a high power. These Naviculse all multiply by
division and conjugation, as do the diatoms generally,
which cannot be explained without plates, and the student
must refer to the works already mentioned.

MELOSEIRA,

From melos (a member), and seira (a chain),

is found on marine algse, a composite plant of man}!
frustules, joined together by siliceous hoops.

MELOSEIRA RORRERI.

No student should be without a slide of Meloseira,
because it is a diatom very likely to be mistaken under a
low power for a mass of confervse. In fact, it has been
misunderstood even by eminent naturalists. Agardh, the
Swedish botanist, found and classed it with the fresh-water
algae ; Ehrenberg examined and removed it into the animal
kingdom under the name of Gallionella ; and now it is
replaced in the vegetable world as a diatom, its siliceous
lorica being quite ascertained, and many beautiful species
found both in salt and fresh water. If possible, obtain a
specimen of Meloseira sub-flexilis, which is found off
Eriburg ; or Meloseira nummulites , found in the Baltic Sea ;
but meanwhile observe this M. Borreri , which is abundant
on marine algse. You see a mass of bead-like filaments,
which towards the edge is better seen and with a high

46

Objects for the Microscope .

power. The frustules, or valves, are quite apparent— cylin-
drical, round at the edges, and with a strongly-marked
central line. Some of the frustules are larger than others ;
in these most likely the process of self-conjugation has
begun.

ACHNANTHES LONGIPES,

From achne (chaff or down), and anthos (a flower).

These now scattered frustules were connected in life by a
stem, and the upper and lower frustules had different
markings. You may observe that some have a transverse
line, forming a cross upon the valve ; this is one of the
lower frustules. Achnanthes are common in sea-water,
attached to algse. There are several species, — some fossil,
others found in fresh water ; but this is the most beautiful.

SYNEDRA ULNA,

From sunedra (a sitting together),

are common in fresh water, sitting together in groups of
golden wands, striated and open at the ends, which in age
dilate, and three obtuse teeth are visible, with openings
between them. These often occur in such numbers as
quite to encrust the confervse, or the stones in ponds and
rivers.

We need but to take a very little of the brown-looking
vegetation which we find on the walls of wells or horse-
troughs, or quiet ponds, and placing it on a slip of glass,
with a drop of water, cover with another piece of thin
glass, to see many of these living microscopic plants.

BACILLARLE,

From baculns (a staff).

These are much shorter than Synedra, and are found
adhering together by one corner, in a zigzag manner, or
free, like naviculse, gliding about in a drop of water. They
are so abundant as to cover the confervse like felt.

Objects for the Microscope.

47

GOMPHONEMA,

From gomphus (a wooden peg),

is shaped like a wooden peg or wedge, and grows like a
tree, on long filaments, attached to confervae or stones in
fresh water, varying in shape, being sometimes round at
the tip, or notched, or with a plain edge.

LXCMOPHORA,

From Ukmos (a fan), and phora (bearing),

grows likewise on a stalk, but in dense masses, and is a
marine diatom, parasitic on seaweeds. Its growth is dif-
ferent from that of the Gomphonema. The stalk widens
in the process of multiplication, and so spreads out the
frustules like a fan.

RHABDONEMA,

From rhabdos (a staff) .

These are marine also, and used as test objects, because,
besides the striations, each frustule has two or four rows of
marks called vittae. They were joined together when
alive, forming a long tube ; but usually we only see the
separated frustules here.

GRAMMATOPHORA MARINA,

From gramma (a letter).

This is used as a test object to discover some very delicate
striae on the borders of each valve, and is also remarkable
for its vittae, which resemble letters ; especially this G.
marina , which has four Greek gammas ( y) on each frustule.
The vittae are internal siliceous folds, and distinguish a large
section of the Diatomaceae. There are fifteen species of
Grammatophora. This one is found on seaweed in the
Atlantic and Pacific oceans.

BIDDULPHIA, — AMPHITETRAS,

Biddulphia is one of the chain-like diatoms which adhere
to one another by projecting angles, or horns. A band of

48

Objects for the Microscope .

minute cells forms a hoop round the valves, and when they
multiply the young cells slip out from between the valves,
and the hoop often becomes detached.

Amphitetras is a square cellular diatom, which frequently
has its frustules piled up one over the other, with a large
cell in each corner of the frustules. They are found alive
in the sea off Cuba and the Canary Islands, fossil in
Bermuda earth and Barbadoes deposit.

ISTHMIA ENERVIS.

A lovely diatom, found on seaweed on the English coast
and in the Channel Islands. Its exquisite areolated struc-
ture is very remarkable, and will repay careful examination.
Its mode of increase is unlike all others. Two cells form
within the valves, and as they enlarge break forth ; but still
the siliceous hoop which once joined the new frustules to
the old one remains attached for a time round one of them
and alters its shape, causing some to appear truncaied
instead of round. The areolae of Isthmia are never well
seen except with the parabolic illuminator, or mounted dry
and viewed with a binocular microscope.

ARACHNOIDISCUS,

From araclmt \ (a spider), and discus.

This beautiful disc is one from the guano, and is also found
attached to seaweed ; especially one species, which is much
used by the Japanese in making soup. It does, indeed,
somewhat resemble a spider’s web. But how can we
describe the wonderful delicacy of its tracery, or cease to
wonder at the perfection of its form, when we learn that
this double disc has two inner valves ; the outer one
horny, upon which are the web-like marks, is indestructible
in nitric acid ; and the inner valve siliceous, supports the
upper one upon fretwork like a gothic window. This
should always be looked at with a Lieberkuhn, or a
parabolic illuminator.

Circulation of the Blood, in Stickleback and Frog.

Plate 8.

1. Stickleback. 2. Small portion of Stickleback’s tail-fin, magnified 35 diameters.
3. Part of Frog’s foot. 4. Minute portion of the web, magnified 100 diameters.

5. Capillaries in web of Frog’s foot, magnified 580 diameters.

Objects for the Microscope.

49

HELIOPELTA,

From helios (the sun), and pelta (a shield).

This diatom is found in Bermuda infusorial earth. We
sometimes find two or three species on the same slide, and
few mounted diatoms are as beautiful as the Heliopelta
viewed as an opaque with the binocular. We then see the
really raised compartments in relief, forming a five or six-
rayed star of exquisite workmanship, with a striated margin
and lateral spines, which are thought to connect the frustules
together when in a young state. The number of rays de-
termine the species. If the heliopelta has a five-rayed star
in the centre and ten compartments, it is H. Leuwenhoehii.
If there is a six-rayed star and twelve compartments, it is
H. euleri. If there is a perfect Maltese cross and eight
compartments, this is H. metii. But is quite necessary,
in order fully to observe the structure, to have two slides of
this diatom, the one for transmitted the other for reflected
light, and the latter must have the Heliopelta mounted
without balsam.

OMPHALOPELTA (CELLTTLOSA VERSICOLOR).

This diatom so nearly resembles Heliopelta, that a little
close observation is necessary in order to detect the differ-
ence between them. The rays, though distinct, are less
raised, and the margin has fewer spines, the rim is broader,
and one species, 0. versicolor, has, with transmitted light, a
play of colour from tawny to red, also a bright, clear, six-
rayed star in the centre, and the rim, though narrower than
0. cellulosa, is very radiant. This is also found in Bermuda
fossil earth, and other species in guano.

ACTINOCYCLUS,

From actin (a ray of light), and cyclus (a circle),

has no marginal spines, and from eight to ten divisions ; is
found alive at Cuxhaven ; fossil in Virginian earth.

50

Objects for the Microscope .

ASTEROMPHALUS ASTEROLAMPRA,

From aster (a star), omphalos (the navel), and lampra (shining).

Look for these in the slides of fossil guano, Bermuda
earth, Virginia deposit, and Piscataway earth. They present
beautiful umbilical rays, reaching only half way towards the
margin, and alternate rays proceeding from the margin,
forming a bright star in the centre, having five areolae in
each marginal division.

COSCINODISCUS,

From coscinon (a sieve),

has no rays or divisions, but resembles the Indian turn of a
fairy watch. The structure is wholly cellular, and the
species, of which there are forty, are known one from
another by minute yet regular markings, tubercles, and
variations in the size of the cells. They are found alive in
the sea off Cuxhaven ; fossil in the Richmond, Virginia, and
Bermuda earths, also in the chalk marl of Oran.

These are the specimens most commonly sold by opti-
cians, and they show us what Diatomacege are ; but to
pursue the study, and learn the myriads which a little
bog-water or a spray of seaweed would reveal, we must
read Pritchard’s work on Infusoria ; or, if further interested
in the manner of their propagation, — which is really won-
derful— read the article “Diatomacea” in the works on
the Microscope by Carpenter or Hogg.

DESMIDIACEJl.

These are minute plants, of green colour, found in fresh
water, shallow pools, and ditches.

VOLVOX GLOBATOR.

This is one of them, which, from its animalcule-like
movement and extreme beauty, has long been considered
as one of the Infusoria. If mounted, it may be beautiful,
but is much more so in its living, moving state, in a drop

51

Objects for the Microscope.

of water ; revolving round and round, sometimes gliding
along, sometimes rolling through the water, a transparent
globe, enclosing from one to seven, or even twenty, lesser
and darker green globules, of various sizes. Each of those
globules in time breaks from its parent cell, and becomes
likewise a mother plant, producing young vol voces with
such rapidity that ponds are often thronged with them,
and the water is coloured to a deep green. There is a
pond at Blackheath which, in the months of July and
August, abounds with Volvox globator.

CLOSTERIUM

is a favourite specimen of Desmidiacese. Its little half-
moons, or ovals, sometimes joined together, are frequently
found in all pools, especially on moors and in exposed places.

Lately the Closterium has been closely examined with
high powers, and a circulation of fluid was seen throughout
the cell. This requires a power of 300 diameters and care-
ful management of light. Then a peculiar whirling move-
ment may be distinguished in the large round space at the
end of the cell, as well as along both the concave and con-
vex edges of the Closterium. It is like the circulation in
Vallisneria, Chara, and Anacharis, which I do not describe,
because I am only noticing those objects which are mounted
for students, in the hope of leading them to examine the
living plants for themselves, with other books of a higher
order. (Read ‘ Carpenter’s Microscope,’ chap, vi., on the
Desmidiaceee.)

To find the Desmidiacese, try small shallow pools, and
not stagnant water.

The Closterium, Euastrum, Micrasterias, &c., will be
found as a gelatinous stratum at the bottom, on stones, or
stems of water-plants. The Staurastrum, Pediastrum, and
all the smaller species, float as a thin film on the water, or
form a dirty-looking cloud round the aquatic plants.

Raise the film with a small muslin net, or pour the water
through your handkerchief, scrape off the deposit, and trans-
fer it into bottles of fresh water for examination at home.

52

Objects for the Microscope.

If on plants, strip the stem with your fingers, and in the
same way drop the gelatinous mass in water. Let it settle,
and the little plants will flourish and remain long enough
for you to study, not only their lovely forms, but also their
manner of propagation, which is threefold. They multiply
by self-division, by conjugation, or by zoospores.

The most common way is this : when a simple cell has
come to its full growth, a partition forms in the middle,
the cell gradually separates into two halves, each of which
speedily becomes a perfect species of Desmidiacea.

The increase by conjugation, observed particularly in
Closterium and Cosmarium, takes place thus : two fronds
approach each other, and the outer cell-wall of each splits
and throws out a connecting-tube which joins them together.
Through this tube the contents of one cell is poured into
the other, and mixing with the endochrome of the receiving-
cell, forms a body called sporangium , which is afterwards
set free by the breaking up of the parent cell.

Multiplication by zoospores has been observed in Cosma-
rium, Pediastrum, and many others. The endochrome
divides into a number of granular particles called gonidia,
which escape through the cell-wall, and develop into per-
fect cells.

Or they are ciliated and have a spontaneous movement,
both in the parent cell and out of it, when they are called
zoospores.

C0NFEBV7E. — ZYGNEMA.

This is mounted for the microscope, as an example of
conjugation amongst the Confervacese.

Confervacese are those plants which form the green or
brown scum on ponds and ditches, and the long green,
silky threads, that float in running water. Most beautiful
are their ribbon-like filaments of varied pattern, and most
useful their life on the stagnant water, which they purify
by absorbing the noxious gases, and giving out the life-
sustaining oxygen.

Looking at this scum for the first time will probably
surprise us as much as anything. It does seem so won-

Wings, etc., of Insects.

Plate 5.

1, Small Dragon-fly. 2, Part of small Dragon-fly’s wing, magnified 7 diameters.

3. Wing of another species of Dragon-fly. 4. Part of wing, magnified 7 diameters.

5. Minute Beetle, common in Spring. 6. Beetle, magnified 30 diameters.

7. Hairs of Beetles, magnified 420 diameters. 8. Wing-case of Beetle, magnified 50 diameters.
9. Teeth at the base of wing-case, magnified 900 diameters.

53

Objects for the Microscope.

derful that what we have passed by unheeded for so many
years, or even turned from in disgust, should be so very
beautiful. The filaments are worked by the hand of God
in such varied pattern, that every pool may furnish us with
a new specimen, and read us a lesson of the infinite care
that has been bestowed on the lowest orders of creation.

The conjugation of Zygnema resembles that of Closterium,
only as the filament is long and divided into many cells,
every cell throws out a connecting tube, and one filament
completely empties itself into the other, remaining colourless,
whilst the recipient has a dark-green star of condensed
endochrome in every division.

ACHYLA PROLIFEBA.

I have come reluctantly to the end of the vegetable slides,
and upon each have said so little of all that there was to say
that I can only hope my few words may prove very unsatis-
factory, and so send the reader to better works and to the
study of that open volume which lies around us, the
hieroglyphics of which our microscope deciphers for us.
Only one more little plant I will mention : it cannot be
mounted, but you may raise it for yourself in a glass of
water at any time. It is a parasitic plant on dead animal
substances in water, and produces the zoospores of which we
have been speaking. Throw two or three dead flies in a
glass of water, and in a few days they will be covered with
a cloudy film of minute colourless filaments ; that is the
plant Achyla prolifera.

I will describe what I saw the first time I examined it.
I found one day in a small glass tank a dead larva of some
aquatic insect, covered with a transparent mould, and on
examining it with a half-inch object-glass, saw a mass of
delicate white filaments. Some of these were filled with
green granules in constant motion, and as I watched them
the filament under observation began to expand into a club-
shaped head, and the granules to form into small angular
bodies, moving slowly round and round. The progress
seemed so rapid, that I took out my watch to time the

54 Objects for the Microscope.

changes, which astonished me. It was a bright July

evening.

20 min. to 7. The angular bodies were forming.

15 min. past 7. The gonidia, or zoospores, as I should call
them, were becoming oval.

20 min. past 7. The gonidia were in violent motion,
revolving and bounding against the end of the cell.

25 min. past 7. The end of the cell contracted and elon-
gated, then suddenly opened like a beak, and out rushed
the whole multitude of little zoospores, merrily swim-
ming hither and thither, evidently ciliated, and always
moving the small end foremost. The empty cell col-
lapsed, and I forgot it in watching the other filaments,
all progressing in the same way. The spores continued
to move about rather more slowly for nearly half an
hour, when the quasi animal life seemed to cease, and
they floated away to germinate upon the nearest
decaying substance.

I hope you will prove the truth of what I write ; it will

afford much pleasure and a most useful lesson.

PART II.

OBJECTS FROM THE ANIMAL KINGDOM.

“ The desire which tends to know
The works of God, thereby to glorify
The great Work -master, leads to no excess
That reaches blame, bnt rather merits praise
The more it seems excess ;

For wonderful indeed are all His works,

Pleasant to know, and worthiest to be all

Had in remembrance alway with delight.” — Milton.

The slides usually prepared from the animal kingdom
consist of insect parts, palates of Molluscs, Zoophytes, and
miscellaneous objects, rather difficult to classify, since
they seem to be mounted chiefly to please the eye of the
purchaser.

The demand for “ pretty objects ” has been caused by the
absence of any plan for the proper use of the microscope ;
but now that we begin to find its real use, and appreciate
its value as an educational instrument, the optician will
have a better selection of slides on sale, and each object
will be chosen as much for its usefulness as for its beauty.

There is a class of slides now sold by several opticians,
which deserves especial recommendation. They are insects
mounted whole ; one single preparation affording material
for a day’s study at least. Instead of isolated parts be-
longing to unknown insects, we have the perfect body of
Fly or Beetle, displaying its external anatomy, and giving
us such an insight into its structure as we should hardly
acquire with much reading and the best-drawn illustration.

Take, for instance, the slide of Scatophaga, or common
Dung-fly, and read the description in this catalogue ; or
the Telephorus Beetle ; and compare the two carefully in all

56

Objects for the Microscope.

their parts ; reading at the same time, from Cuvier, or
Westwood’s 4 Introduction to Entomology,’ the generic
characters of the Coleoptera and Diptera, and the young
entomologist will have received a lesson never to be forgotten.

For those who have not begun the study of natural
history, a few words are added on the classification of
insects generally, without which some descriptions may be
unintelligible.

Insects are so called from the word in-secta , their bodies
being divided into many distinct segments. They are a
class of invertebrate articulated animals. The head is
always distinct and furnished with antennae ; the body
usually consists of thirteen segments ; they breathe by
means of tracheae ; possess a nervous system, a circulation
of blood, and a digestive apparatus varying with the
necessities and habits of the species.

According to Cuvier’s arrangement, insects are divided
into twelve orders. The first four orders have no wings.

1 . Myriopoda, example

2. Thysanura ,,

3. Parasita ,,

4. Suctoria „

5. Coleoptera „

6. Orthoptera „

7. Hemiptera „

8. Neuroptera ,,

9. Ilymenoptera ,,

10. Lepidoptera ,,

11. Strepsiptera „

12. Diptera ,,

The objects themselves will be the best illustrations of
these orders.

Preparations of animal tissues, blood, injected respiratory
and digestive organs, and other objects relative to the
physiology of the human body, are reserved for a separate
pamphlet.

Julus or Centipedes, and
Woodlice

Lepisma, or Sugar-louse
Pediculus (Louse)

Pulex (Flea)

Beetles

Grasshoppers, Crickets
Bugs, Aphides
Dragon-flies

Bees, Wasps, Ichneumons
Butterflies, Moths
Stylops
Flies

Objects for the Microscope .

57

CHAPTER I.

OBJECTS FROM THE ARACHN1DA.
spider’s foot, jaws, spinnarets, eyes, epidermis.

spider’s foot.

This favourite object should always have three companions
in its box — a preparation of Spider’s eyes, Spider’s jaws,
and Spider’s spinnarets, — therefore I shall say something
of each of these, and also a little of Spiders themselves.
W e are so familiar with them, so apt to dislike them in the
house and overlook them in the garden, that it will be well
to learn somewhat of their history.

Few persons realize the dignified position they hold in
the order of creation. They are called insects ; and are
certainly not considered so aristocratic as Butterflies, or so
grand as the great Beetles ; perhaps a little higher than the
Fly they so cunningly ensnare. Therefore let us consider
the Spider as a whole before we examine his foot.

The Spider is not an insect It ranks higher than any
insect, no matter how large or how beautiful ; and this on
good grounds. In all God’s works a perfect plan and
regular order are established, and the organization of
living creatures is gradually perfected, from the lowest
form of animal life in the simple ciliated monad, up to
the elaborate anatomy of man. Now the Spider might be
an insect if we strictly adhered to the meaning of the term
in-secta (divided into parts) ; but as its internal anatomy is
more perfect, its respiratory apparatus, its circulation, and
mode of reproduction, superior to those in any of the
twelve orders of insects , the Spiders are called

ARACHNIDA,

and placed above them in natural order.

The Arachnida have oval or round bodies ; the head,
which is joined to the thorax, has simple eyes, which in

4

58

Objects for the Microscope.

structure more nearly resemble the animal than the insect
eye. Sometimes there are eight, sometimes six, or only
two. They have a mouth with jaws (: maxillae ), a tongue
( iiyula ), remarkable palpi, and frontal claws often of great
magnitude. But the nervous system is the great distinction.
The organ of sensation, which is the brain in man and
animals, is a series of knotted nerves called ganglia in insects,
from which proceed nerves to all parts of the body. The
imperfect insect, such as a Caterpillar, has more ganglia
than the perfect butterfly. And whereas the insect has
generally from six to eight or ten ganglia, or little brains,
in different parts of its body, the Spider has but two , and
they more brain-like, more concentrated, and consequently
of a higher order.

Then again as to the circulation : we know that in all
creatures the blood is the life ; it is the fluid which nourishes
all parts of the body. Not always red; it may be white,
or yellow, or green ; but it is blood, and constituted more
or less like our human blood, as the microscope reveals.
All insects have a heart or dorsal vessel which pumps out
the blood (as we shall see explained when examining the
larvae of ephemera) that circulates loosely in the body,
bathing the air vessels which supply it with oxygen ; but the
Arachnida have a true heart ; long, indeed, like the insect
heart, but furnished with arteries and veins which give it
perfect circulation. This raises it another step higher.

The respiratory system is different in various species ;
but the Spider whose foot we are looking at had lungs or
pulmonary sacs, with two or four breathing orifices, situated
just near the base of the abdomen, and inside those sacs a
number of delicate white triangular plates which aerated
the blood. This is more like animal respiration than the
trachea of insects. (See Spiracles.)

The Arachnida do not undergo metamorphosis. The
female lays eggs, making very pretty cocoons or nests for
them, and the young Spiders come forth perfect from the
shell, with the exception of the two fore legs, which are
not always developed until a lew days after their birth.

And if we read any good work on the Arachnida we

Objects for the Microscope.

59

shall not fail to be struck with the intelligence of their
habits and the amount of their instinct. For instance, in
the structure of their habitations, one species (Clotho*)
found in the south of Europe makes a beautiful tent in the
shape of a cup, festooned at the edges, with the outer cover-
ing of the finest texture, like taffeta, and weaves a second
apartment, of still softer material, for her young. In this
inner room, kept scrupulously clean, she hangs five or six
little bags, wherein her eggs are laid enveloped in fine
down. When she goes in and out of her tent she lifts the
edge of a festoon and drops it again. The My gale Spider,
whose nest you may see in the British Museum, brought
from Jamaica, is made of the hardest clay, having a trap-
door fitting most exactly, and hinged with stout layers of
silk ; the use of which she knows so well, that if it is half-
opened by an intruder, she will pull it strongly inwards to
defend herself.

The cunning and amusing way in which the Hunting
Spiders catch their prey — creeping under a twig or window-
ledge as gently as a deer-stalker, lying motionless for a
while, moving as the Fly moves, turning with incredible
swiftness round and round, ever keeping the prey in sight,
until, quite certain of its being within reach, they spring
like a Tiger, as fierce and as unerring in their leap.

We may watch these ourselves in our garden on a warm
spring day, e.g. a little black and white striped Spider,
called Salticus, which, before it leaps, cautiously fixes a
good strong thread to the wall in case of a fall.

Again, we may see high instinct and deep affection in
those vagrant Spiders of the wood, Lycosse, which hunt
with their cocoon of eggs so firmly clasped to the body
that they will die rather than part with it.

A wise little Spider of our neighbourhood — its name I
do not know — lives on the ponds and ditches of Otmoor,
and spins a web round a kind of raft of Lemna, with a stem
of grass or a little twig — to make it stronger, I suppose —
and floats about on this, pouncing on any half-drowned or
newly-hatched Fly which may come within its reach.

* Uroctea.

60 Objects for the Microscope.

Last of all that I shall mention, — as paper would fail me
if I noticed all our spider friends, — is the Diving Spider of
our aquariums (. Argyroneta ), common near London, rare in
many parts of England : which has been taught to make a
diving-bell for the work which God has appointed her. The
water-world requires its avengers to keep down the fast-
multiplying creatures therein, and the Argyroneta aquatica
is one of them. True her gill-like lungs enable her to
breathe under water ; but still she requires more oxygen than
it affords, and comes up about four times an hour for a
supply of air. This she conveys to a silken house she has
previously spun amidst the weeds in still water, and which
we see shining like a little globe of silver ; the Spider halt
inside, her breathing organs immersed in the air, and her
head outside, watching for a tiny Beetle or a little Cyclops.
Eor a more detailed account of the Water Spider, see
‘ Kirby and Spence’s Entomology,’ or the smaller work called
‘ Insect Architecture.’ I only mention these facts to prove
the reasonableness of the high position the Arachnida hold,
and the unreasonableness of the neglect and dislike they
often meet with. I bring them forward because the whole
Spider is to be purchased beautifully prepared, and its
external parts may thus be studied ; also because the comb
of the foot is in every collection, and it is more interesting
when we have some further knowledge of the body to
which it once belonged.

spider’s foot.

The Spider’s legs have a different formation from those
of insects. Each has seven joints ; the two upper ones
form a kind of haunch ; the next is the femur ; the fourth
and the fifth are tibiae ; the first or second according to
the species, much the longest ; the last two are the tarsi,
less distinct than those of insects, but remarkably furnished
with toothed claws called the combs. In our Garden
Spider, the Epeira, there are no less than five of these
combs, besides three upper and untoothed claws, to each
foot; also a strong moveable spine or hook at the joint of
each tarsus.

61

Objects for the Microscope.

The use of these combs is for cleaning itself and its web,
the Spider being a most tidy creature. It has been seen
to spend an hour or more in scraping the delicate threads
of its web, when dust or soot had collected on them ; and
if they were too thoroughly incrusted with dirt, these little
claws broke the thread, rolled it up, and threw it away.

The combs have from fifteen to seventeen teeth, necessary
for the swiftly running Spider when crossing the fragile
web or twisting the silken bands that form its dwelling or
its snare.

Whoever has patiently watched a Garden or a House
Spider spinning its web, will have noticed how with these
claws it shakes and tries the strength of each supporting
line, and is able to cling to it or roll it up by means of these
handy little combs, as well as to regulate the issue of the
threads from the spinnarets, — as it were reeling it off.

spidee’s spinnabets.

These are not always well prepared. They are difficult
to keep in position, but you could see them well by catching
a good-sized Spider, and examining it as an opaque object.
At the end of the abdomen you will find four or five teats
or spinnarets, pierced with an immense number of minute
holes, from which a viscid fluid, a kind of glue, exudes at
the will of the animal, and is drawn out as a fine thread. In
reality, each of those fine lines which we can scarcely see is
composed of thonsarids of threadlets, for there are often
1,000 orifices in each teat. The fluid, first uniting from all
these in one twist, descends about the tenth of an inch, and
then twining with the three or four others, it becomes a
cable in structure and in strength.

The formation of the web would be too long a process to
describe here. Only one fact I add ; which is, that the
Spider makes two different kinds of thread, and every web
is fashioned of these different materials.

Take one of those common garden geometric webs, and
throw a little fine dust against it. Look closely ; you will
see that the dust adheres to the cross lines which form the
circles, but not to the radii or supporting lines. This is

62

Objects for the Microscope.

because the Spider secretes a viscid matter, which she
deposits in little globules all along each circle, and which
acts as bird-lime in securing the prey. In one web of
moderate size not less than 87,360 of these globules have
been counted ; and yet the time occupied in its whole
construction was only about forty minutes.

I often think that invalids, or mechanics, or town-people,
who cannot enjoy many of our country pleasures, or learn
God’s wonderful ways in the instinct He has bestowed upon
our humble fellow-creatures, might find much profit, much
amusement, if they only knew a little more about the flies
on their window-pane, and the spiders on the wall. And
those careful housewives who so diligently sweep away this
beautiful work, might leave just one sometimes, as a little
page from God’s Book of Creation, which, if rightly studied,
would lead to happier thoughts than come with the over-
carefulness about household matters.

spider’s eyes.

I have said already that the eye of a Spider is of a higher
type than the compound eye of insects. It has a single
arched cornea, a spherical lens, and a concave vitreous body,
with a cup-shaped retina and a layer of pigment cor-
responding to the choroid membrane of the animal eye. It
shines in the dark like a cat’s eye, and evidently can see in
the night as in the day. This is very remarkable, and de-
notes higher organization than we find even in the aggregate
lens of a Butterfly’s eye.

The position of these eyes — for the Spider has six or
eight — is admirably varied for their different habits and
pursuits.

The Garden Spider, Epeira, has two very large red ones in
front and two behind, forming a square ; two on each side
almost confluent.

The House Spider has a double row of four each arching
the forehead.

The Hunters have two fierce large eyes in front, four
little ones just beneath, and two some distance behind, like
watchmen or an “ arriere-garde.” Whilst the common

63

Objects for the Microscope.

Phalangia, or Harvestmen, which run always on the ground
amongst moss and leaves, and are of the lowest rank in the
society of Spiders, have but two eyes, seated on a tubercle
or watch-tower on their back.

There are seventeen different positions at least in the
eyes of those Spiders most common to us.

spider’s jaws.

The jaws or chelifers of the Spider — properly speaking,
the mandibles — are various in form, but always tremendous
weapons, not only from their size and sharpness and the
serrated edges and spines with which they are beset, but
also because the upper joint contains a little sac of intense
poison, which is emitted through a minute orifice in the
next joint, and effectually kills whatever insect is bitten.

spider’s palpi.

The palpi, or feelers, serve as organs of taste and touch,
and also as distinguishing marks of the sex. The male
Spider has very large knobbed palpi, by which it is easily
recognised.

EPIDERMIS OF SPIDER.

The skin of the Garden Spider ( Epeira ) is frequently
mounted, and displays very beautiful undulating lines,
surrounding the roots of the hairs. These concentric
markings arise from the existence of folds in the inner
membrane, beneath which lies a layer of pigment cells, to
which the variegated appearance and beautiful colours of
the Arachnida are owing.

The skin is merely washed, dried, and mounted in
balsam.

64

Objects for the Microscope .

CHAPTER II.

INSECT PARTS.

TONGUES OF INSECTS.

TONGUE OR PROBOSCIS OF HIVE BEE.

This is a common and favourite object in all collections,
and very beautiful ; but it should always be one of at least
five others in the insect division, in order rightly to appre-
ciate and enjoy the exhibition it affords of adaptation for a
particular purpose.

A moderate power gives a view of the whole tongue, so
called, which in truth consists of several parts. The habits
of the Hive Bee are well known, and need not here be
described ; but it is worth observing how beautifully this
organ is adapted for gathering the honey which lurks in
the deep nectaries of such flowers as the Columbine or
Honeysuckle.

Those strong-looking maxillae are chiefly used as pro-
tecting sheaths for the delicately fringed and jointed ligula
or tongue, which is stretched forth, having two feelers,
called labial palpi, one on each side. These palpi are jointed
at the tips, and used for steadying the proboscis in the
flower-cup as it laps up the sweetness there. The ligula
has forty joints, or more ; the number varies with the
species ; you will easily see them with an inch lens. They
render it perfectly flexible, as it sweeps round both concave
and convex surfaces ; and with a tremulous lapping motion
the fluid is drawn up along the hairy channel into the
opening valve which protects its throat. There is a knob
or kind of button at the tip, which has been falsely supposed
to be a perforated sucker. The tip of the tongue is simply
cartilaginous, but the base is hollow and capable of inflation
to a considerable size. In this hollow part the nectar drawn
from the flowers is collected previous to its passing into the
honey stomach.

Objects for the Microscope. 65

If possible, the jaws or mandibles of the Bee should be
mounted with the tongue, to show the instruments with
which they fashion their waxen cells, seize their enemies,
destroy the drones, &c. The mandibles vary in form and
power with the different necessities of the species. The
Hive Bee has simple spathulate jaws; the wild Humble
Bee has toothed and stronger ones ; as also the Carder Bee,
Mason Bee, and Carpenter Bee.

A comparative view of the tongues of these Bees would
be most interesting, and for those who like to make a
collection I will give the easiest way of preparing them for
observation.

Soak the heads for about a fortnight in liq. potassse,
to soften the skin and dissolve the fatty substance within,
which prevents the parts from being distinctly seen. Then
wash them in water, and press them flat between two pieces
of glass until quite dry ; drop a little turpentine upon them
and let them soak in it for a few days, when they will
mount beautifully in Canada balsam. If bubbles of air
remain in the tissue, lay the tongue on a glass slide, and
cover it with a piece of thin glass ; take a camel-hair
pencil and drop turpentine between the glasses, which
must now be suffered to boil over the spirit lamp, and the
air will rush out in bubbles ; keep supplying turpentine
until the object is perfectly transparent, then quickly and
gently apply the balsam.

TONGUE OF WASP.

How very different this is from the tongue of the Bee!
Instead of the long and slender ligula, here is a short
broad two-lobed membrane, far more useful to the Wasp,
who does not trouble himself to collect the honey he will
eat ready-made out of the comb, but who prefers rasping
rapidly away the soft ripeness of the Peach, the Apricot, or
the Plum ; or gnawing the juicy meat at the shambles, or
sucking out the life of a fat Ply. This broad flat membrane
— how handy it must be in making those curious paper nests
wherein they rear their young ; a trowel and a smoothing
iron, a spoon and shovel, as may be required ; and with

66

Objects for the Microscope.

those two brushes on either side ever keeping it clean and
unclogged for its work ; whilst those four feelers, the labial
palpi and maxillary palpi, ceaselessly vibrate over all, to
ascertain the fitness of food or material.

There are many species of Wasps ; and some of them,
especially foreign ones, feed more upon honey than do our
common Wasps, and their lin guise are therefore modified
for their wants, being longer and sometimes three-lobed,
with a variation also on the mandibles or outer jaws.

These would make a very interesting collection prepared
like the Bee’s head.

butterfly’s tongue or proboscis.

This is a beautiful piece of mechanism ; a long elastic
coil which the hovering Butterfly throws lightly into the
recesses of the deepest corolla. It cannot, like the Bee,
dive down into the Honeysuckle or Campanula, or passion-
ately tear open the nectary of a Foxglove. Its beautiful
wings cannot fold so closely as to let it creep into the
Salvia-cup or Lily-bell. Therefore its Creator gave it this
excellent instrument adapted exactly to its wants. In the
living insect it is coiled closely to its head, so as to be
scarcely visible, and not at all to impede its movements.
When unfolded, we perceive that it consists of two long
tubes hooked together most curiously by minute teeth,
which on either side are inserted into little pits between
each row of teeth. Moreover each of these tiny teeth has
a second tooth, which forms a deep notch, and prevents the
accidental unhooking of this double tube. Then at the
edge of each tube there are seventy-four little barrel-
shaped bodies, or papillae, considered to be the organs of
taste, and inside each tube, which you may observe is
delicately striated, there are spiral vessels or tracheae con-
nected with the larger tracheae in the head. Now the
fluid does not pass up the interior of this antlia , which
is its proper name, but is drawn upwards along that
channel which is formed by the union of the two tubes.
The papillae are best observed near the tip, and with a high
power.

Objects for the Microscope.

67

PROBOSCIS OR TONGUE OF BLOW-FLY.

This is a true proboscis, but not so well seen alone if all
its parts and uses are to be considered ; you should have
the proboscis of a Gnat and of a Tabanus or House-fly
rightly to understand the whole.

We see the little House-fly busy in our sugar-basin, or
the Blow- fly, unwelcome in our larder. We feel the tire-
some tickling on a hot summer’s day when they gambol
over our hands and face ; but we know not how beautiful
is that little mischievous tongue. Here it is spread out,
the simplest form having a broad fleshy lobe which is
striated with spiral fibres, by which it obtains a sucking
movement and draws up the juices it feeds on. Little short
stiff hairs are set around it, and these are what do us
mischief in rasping off the polish of our book-covers, and
causing the irritation to our skin.

PROBOSCIS OF TABANUS.

This is the more complicated proboscis of the Tabanus,
or Horse-fly. Who does not know how it torments our
cattle, and the carriage horse in particular, in a dusty drive
through the country ? A large brown Fly, with variegated
wings, and such magnificent eyes ! She is easily caught ;
for when she fixes on the horse and tastes the warm blood,
her whole attention is given to the feast. I say she , be-
cause the male Tabanus is found harmlessly hovering over
flowers, and loves the haunts of the Honey Bee : his mouth
has no lancets, whereas the female is supplied with very
powerful instruments of assault.

The head should always be mounted with the proboscis,
which greatly increases the interest of the slide ; because,
although the eyes lose in preparation their gorgeous colour-
ing of green, purple and gold, in zigzag bands across the
facets, yet the delicate network remains, and shows the 4,000
meshes, which in life each contained an eye. As is the
case with many of the Diptera, the eyes of the female are
parted by a narrow band. Beneath the eyes, near the
mouth, are the antennae, which are supposed to be organs
of hearing, as they certainly are of feeling. Six-jointed

08 Objects for the Microscope.

these are ; the first and second bristly, the third is very
long, and the last three very short. It is important to
observe these things, as the shape of one joint in the an-
tenna? will determine the species. In this very case, if we
were examining the large and true Tdbanus bovinus, we
should see a very different third joint.

Next let us examine the mouth.

That long and broad membrane is called the labium.
Those lines at the inner edge of the two lobes are spiral
muscular fibre, which enable it to lap or draw up the fluid
it feeds on ; and those lancets are instead of jaws, or rather
are modifications of the mandibles and maxillae, which are
the inner and outer jaws of insects. These lancets pierce
the skin, and the labium sucks the blood of the horse. If
the slide has the head of Tabanus bovinus , and not the com-
mon Tabanus pluviatilis, also called Haemotopota, or “ blood-
drinking,” the head will be armed with a strong pair of
mandibles besides the lancets. The larvae of these flies
live in the earth — long grey footless grubs, feeding on
decayed vegetables.

PROBOSCIS OF GNAT.

Here is another of our little tormentors, and a female
Diptera also ; for the male Gnat dances gaily in the sun-
shine with his beautiful plumed head, and has not by any
means so well-developed a mouth. He does not suck blood,
and probably sips a little nectar from flowers or the dew
upon the leaves in the short time he has to live : the busi-
ness of his life is to choose a mate and die. The female
Gnat lives longer, and is very bloodthirsty. Here observe
a long fleshy lip, or labium, which is the sheath containing
two mandibles, two maxillae, one labium, one ligula or
tongue. They may not all be visible on the slide, as some
may remain inside the sheath, and some may be broken off,
they are so very delicate ; but if perfect it would show all
these. The mandibles are finely toothed like a saw, but
you require a quarter-inch glass to see this well. The
ligula is shaped like a spear-head. The stiff horny labium is
pointed like a needle. When the Gnat pierces the skin.

Objects for the Microscope.

69

the two serrated mandibles work rapidly up and down, the
sheath folds backward, the pressure of the lancets causes a
little poison-bag, situated at the base of the proboscis, to
emit one drop of acrid matter, and when the little creature
has sucked our life-blood, and her small body is distended
and crimsoned with her draught, she flies off like a winged
ruby in the sunlight, that little poison-drop rankling in the
wound and causing our after uneasiness and irritation. It
is worth the slight annoyance, however, to watch the process
of her feast. With a pocket lens we can see the working
down of the lancets, and the up-flowing of the blood into
her stomach.

The shrill buzz of the Gnat, like a fairy clarion, is peculiar
to the female, and only heard when she is bloodthirsty.
Her delicate wings then vibrate 3,000 times in a second,
and are supposed to cause this sound by the friction of their
bases against her body. Her eyes, which quite cover her
head, and the long fourteen-jointed antennae waving to and
fro, make her a beautiful object, in spite of her unpleasant
propensities.

PROBOSCIS OF ASILUS.

The Asilus is one of the Diptera (Flies) — -the largest and
fiercest of them — most frequent in sandy situations. They
flit about in the hot sunshine, pouncing upon all smaller
flies — Beetles and Hymenoptera, Ichneumon flies, &c. —
holding them between their fore legs, and plunging their
sharp lancets and fleshy tongue into the softest part of their
prey. The colour of these flies is mostly tawny, gold-
coloured, or reddish-yellow ; the wings finely-veined and
clouded at the edge ; the body long and narrow. The
larva lives in the earth : it has twelve segments, and
changes to a spiny pupa, from whence the Fly emerges in
June.

PROBOSCIS OF EMPIS-FLY.

The Empis is often called the Snipe-fly, from its remark-
able labrum, which really resembles a Snipe’s beak. When
at rest it is folded close to the breast, but very frequently

70

Objects for the Microscope.

is seen transfixing the body of some poor smaller fly which
the Empis is greedily sucking. The Empidse are generally
small black flies, and there are many species of them.
They are more fully described with the slide of Empis
stercorea ; also the peculiar veining of their wings.

PROBOSCIS OF DIOCTRIA,

one of the Asilidse, flies which inhabit meadows, trees and
bushes, feeding on lesser flies, and more common than the
true Asilus. They are usually black and shining, and carry
their antennse very fiercely erect. The head should be
mounted in profile to show the tubercle upon which the
antennae are seated, five-jointed and porrect, close to each
other at the base and diverging outward. The proboscis
stands out almost horizontally.

HEAD OF CON OPS.

This is a pretty black and yellow Fly, frequenting flowers,
having a bright triangular spot on the top of the head.
The thorax with two yellow scapulae, and the abdomen is
banded black and yellow. The remarkable part of the head
is a singular proboscis curved suddenly upwards ; a labrum
notched at the tip, arched above and hollow beneath ;
labium bilobed and slightly hairy, with three shallow
transverse furrows at the tip. The antennae should be well
displayed, for their structure alone would determine the
species, and therefore furnish a useful lesson on the absolute
necessity of minute observation, if we wish truly to learn
and enjoy the insect world.

The antennae of Conops are about as long as the head,
fiercely seated on a tubercle, and have seven joints ; the first,
short and slightly hairy, forming an angle with the second,
which is much longer and rather club-shaped : the third
is seated on the second like a cone, and the fourth is very
small ; so is the fifth, and the others are like little spines ;
nevertheless they are seven in all. The eyes are prominent
and oblong ; but the eye of the Fly is particularly described
in the head of Rhingia.

Objects for the Microscope.

7J

HEAD OF RHINGIA, OR SYRPHUS.

This beautiful preparation is the one I have chosen for
drawing particular attention to the eye of the Fly. That
fine delicate lace, now perfectly transparent, is the skeleton
or framework in which were set four thousand perfect organs
of sight, which we call the eye of a Fly. That outer mem-
brane, which is all that is now left, is the cornea ; it was
lined with an intense black pigment, excepting one tiny
spot in the centre of each facet, through which the light
was admitted. Behind the pigment was a broad zone,
orange-coloured and black ; then a second zone, deep blue
or black ; then the optic ganglion, gathering all the fila-
ments of each eye into one knot — the brain.

The brain of insects is not a solid mass, or great ganglion,
like the brain of animals ; but the medium of communica-
tion between insects and the external world, is a nervous
system consisting of two medullary threads or cords, and a
series of knots or ganglia placed at intervals throughout
the body.

Larvae have usually two of these ganglia to each segment
of the body. The perfect insect has fewer ; but the first
ganglion, as in the Fly, always sends out the nerves of the
eyes, tongue, maxillae, mandibles, and antennae. Therefore
we understand how the organs of sight are united in the
head of a Fly upon the first ganglion or brain. And whilst
each eye receives a perfect image of the object before it, one
single impression may be conveyed to its possessor.

This head of Rhingia has also a very beautiful tongue,
long and slender, lobed and edged with spiral fibre, capable
of great extension to accommodate the habits of the Fly.

The Rhingia campestris , or Rostrata, is so called from
its projecting horny beak. It is a very pretty Fly com-
mon in woods and gardens during the summer ; remarkable
from its hovering like a Humming-bird over the flowers,
and darting suddenly into them, sucking the honey-drop
with this long and slender ligula, and then out again with
a swift jerking flight not very easily followed. Its body
is a dull red ; the wings finely veined, like all its family,
the Syrphidse.

72

Objects for the Microscope.

HEAD OF DRONE-FLY, OR HELOPHILUS.

This so nearly resembles the Rhingia that little need ^
added in explanation, except of the fly itself, which is one
of the Syrphidse, nearly related to the Rhingia. The Helo-
philus is that large black and yellow fly so common in the
autumn on Michaelmas Daisies, often mistaken for a Wasp,
as it makes a loud humming noise and is very intent upon
its feast. It passes through a greater change than most of
the fly tribe ; for it lived and fed in the foulest sewer as a
rat-tailed larva which is very curious in its manner of
breathing. This larva has a long retractile tail, with the
action of a telescope, capable of immense extension to reach
the surface of the water or mud for air. The body being
very transparent, the tracheal vessel is distinctly seen in a
wavy line the whole length of the tail.

HEAD OF ERISTALIS,

differs only from Helophilus in having a black hairy body,
more like a Bee. The antennse are very beautiful.

HEAD OF TIPULA.

This favourite and beautiful preparation is the head of
our familiarly called Daddy-long-legs. The colour adds to
the beauty of the lacework eye, and the fine antennse, simple
yet varied in the length of the joints, which are each
slightly hairy. The palpi have four joints, and bend over
the broad fleshy proboscis, in which large trachea are
distinctly seen. These Tipulee are very destructive in the
grub state. The female deposits her eggs in deep burrows
by means of a long ovipositor, consisting of four pieces ;
two of them bore like an auger the required hole in the
earth, and the other two join and conduct the egg to its
appointed place. When the larva hatches it has two short
horns on its head, several fleshy conical appendages on the
abdomen, and two very strong mandibles working against
two horny convex dentated plates. Very destructive are
they to the farmer’s grass land, often destroying hundreds
of acres in England and France. The more, therefore, of
these beautiful heads that are thus prepared the better.

Objects for the Microscope .

HEAD OF LIMNOBIA.

This is essentially like the head of Tipula. I need only
say that Limnobia is one of the same family, only of a
different genus, and the larvae are much less destructive,
living mostly in fungi.

HEAD OF HEMEROBIUS.

This is usually mounted as an opaque object, to show
the metallic lustre of the eyes. The Hemerobius belongs
to the order Neuroptera. Is has four exquisite light green
wings resembling delicate lace, and lays its eggs on the
twigs of lilac trees ; these eggs are stalked and placed in
rows along the twig, from which a very useful little larva
emerges— a destroyer of the Aphides.

HEAD OF PANORPA.

The Panorpa is called the Scorpion-fly, and is very
common on nettles in the middle and end of summer.
They are not difficult either to distinguish or to catch ; for
the male fly is very conspicuous with his long turned-up
tail, at the end of which he brandishes an unpleasant-
looking pair of forceps. The wings, four of them, are
highly reticulated, which denote it to be of the order Neu-
roptera, and first cousin to the beautiful Dragon-fly and
brilliant Hemerobius ; they are prettily spotted, and of
equal size. If we look at the head we shall see a pair of
long antennse inserted between the eyes, three ocelli, or little
eyes on the crown of the head, and this long snout-like
proboscis, with mandibles, maxillse and lower lip nearly
linear, and four or six short palpi. Upon this beak we
often see a little insect spitted, whilst the tongue is rapidly
sucking out its life’s-blood. The Panorpa is a carnivorous
fly, and hunts in the hot sunshine, not only on the wing,
but running swiftly under and over the nettle-leaves, intent
on his pursuit, and easily captured himself whilst thus
engaged.

5

74

Objects for the Microscope,

TONGUE OF CRICKET.

(Aclietoe.)

This is an example of a true insect tongue, and must
be examined with several powers if we wish to see all its
beauty. For a general view use an inch lens, and observe
the two strong muscles which move it, from whence nume-
rous fine spiral fibres arch over the transparent membrane.
Afterwards use the half-inch and the quarter-inch, when
these fibres appear to be furrowed or fretted, like little files,
and must form a most useful tongue for the voracious
Cricket. We all know how destructive it is in the house ;
gnawing linen or books, or feeding on flour, meat — in
short, anything it can find. After this tongue has performed
its office, there is a complicated gizzard, which will be
explained in its proper place ; though it ought to be looked
at after the tongue, and with the wing-case of the male
Cricket, whose drum and file is a very interesting micro-
scopic object.

The House Cricket belongs to the order Ortlioptera , or
straight-winged insects. The female does not chirp ; she
is known by a long pointed ovipositor, with which she
deposits about 300 eggs in a season.

GIZZARD OF CRICKET.

This is a most interesting object in connection with the
tongue of the Cricket, as illustrative of the digestive organs
Df the Orthoptera. It is usually mounted in Canada balsam
and viewed with transmitted light ; but the effect is more
beautiful, and the structure better displayed, by examina-
tion with the parabolic reflector, or a simple Lieberkuhn,
when the scale-like plates are thrown into relief, and the
formidable apparatus for digestion is manifest.

The Cricket has a long and dilatable oesophagus, which
ends in a crop or sac for the reception of food in a rough
state, and this is followed by a gizzard, consisting of two
skins, the inner one plaited into six folds having longitu-
dinal rows of teeth resembling toothed scales, the outer
row much smaller than those in the centre, and each

75

Objects for the Microscope.

capable of elevation and depression. The whole grinding
machine is moved by thousands of muscles, which enable it
to reduce the food to a pulp, and it is then passed on to the
intestinal canal or lower stomach, where biliary vessels,
analogous to the liver in the higher animals, pour in the
bile, which finally prepares the food for the general nourish-
ment of the body.

A most interesting collection of gizzards may easily
be made, and the variation and adaptation of structure
observed, by preparing the stomach of Dytiscus, of the
large Grasshopper or Locust, the Cockroach (Blaps), Tene-
brio (Beetle) and most of the predaceous Beetles. One
small Beetle, a wood-borer, Cryptorhynclius lapathi, has a
gizzard so minute as hardly to exceed a large pin’s head in
size, and yet it is said to be armed with no less than 400
pairs of teeth, moved by a far greater number of muscles.

MOUTH OF BEETLE.

( Telephora , or Soldier -beetle.)

This is a common and favourite object, and should be
considered carefully, for it belongs to that large and useful
tribe of insects which we could no more spare from their
place in creation than we could the flowers of the field, or
the birds of the air.

A Beetle’s mouth will be more interesting if we say a few
words about the Beetles themselves.

Coleoptera they are called, from two Greek words, signi-
fying “ wings in a sheath.” No less than 30,000 species
are known, of which 3,600 are found in Britain ; exceeding
the amount of all our other native animals, and forming
a third part of our insect population. They vary in size
from the great Prionus, wrhich measures six inches long, and
has nine inches expanse of wing, to the minute Trichopteryx
and Atomaria, hardly one-eighth of a line — quite micro-
scopic ; and yet every external joint, every internal organ,
is as perfect in the small as in the large.

The usefulness of the Beetle tribe is far greater than is
imagined. Not only in the perfect state do they remove
dead animal substances, excrements, &c., but in their larval

76

Objects for the Microscope .

state feed on decayed vegetable matter, which else would
render the air unwholesome for our existence, and more
offensive to our senses than can well be imagined. Let us
examine, therefore, the mouth of our little scavenger.

It has six parts. An upper lip, called labrum, which covers
the mouth, and is horny or leathery, but simple in form.

Two upper jaws, called mandibles , varying in shape, but
strong and toothed, or hooked, for seizing their prey and
tearing it to pieces before it is passed on to the more deli-
cate under jaws or

Maxillae , which are fringed with delicate hairs, and to
which are attached jointed palpi, or feelers. The tips of
these are often triangular, or hatchet-shaped, which will
distinguish them for your observation. These palpi move
very rapidly, apparently examining the food, and two others
are attached to the under lip or

Labium , for the same purpose. Part of the labium is
called the chin or mentum, usually having a notch in the
centre. Some of the Beetles have a distinct tongue inside
all this — the Dung-beetle for instance — lying between the
labium and labrum. It is a simple membrane, sometimes
fleshy, sometimes horny.

The mouth of a Beetle would be much better examined
by taking a large Beetle, and soaking the head for a few
days in liquor potassse ; then washing it in a watchglassful
of water, when the parts are easily separated and studied.
Do this, because from one mouth we cannot learn all that is
useful or interesting. For instance, in the mandibles are
found different kinds of teeth ; molar teeth for grinding
food, or incisive teeth for tearing it. The maxillfe also
vary extremely in their form and appendages. The lobes
are often furnished with spines or teeth, and are single or
double, fringed or plain ; but the predaceous Beetles have
always fringed lobes like stiff brushes, as if for cleansing
the food or the other appendages of the mouth. Also, I
may mention that the palpi of those Beetles which feed
on the pollen of flowers, such as the tribe of the Nitidu -
sidce, are used by them to open the anthers in a very
curious way.

77

Oojzczs for the Microscope.

The antennae of the Beetle are not described here but in
connection with those of the Blow-fly and Bee, concerning
which some interesting discoveries have been lately made.

MOUTH OF BEETLE.

(Bouche et palpes de Calathus Castelloides.)

This is a black Beetle about half an inch long, very
common in the neighbourhood of London ; found under
stones.

The object is good as showing beautifully fringed
maxillae with two pair of labial palpi ; the outer pair have
four joints, the lower pair only three. Some species of
Coleoptera have one pair of labial palpi, and one pair of
maxillary palpi.

Observe, the little tonguelet in the centre has two ear-
like appendages, called paraglossae. That broad curved plate
above it is the mentum, with a notch in the centre, which
distinguishes the section of the Carabiei to which it belongs.

MOUTH OF BRACHINUS.

(Bouche et palpes de Brachinus.)

The mouth of the Bombadier Beetle ( see leg of Brachinus),
one of the Carabiei, which has the maxillae terminated
simply in a point ; the tonguelet exposed, and labial palpi
distinctly three-jointed ; the mentum not toothed ; the last
joint of both maxillary and labial palpi evidently dilated.

MOUTH OF ONTHOPHAGUS.

(Bouche et palpes.)

One of the Dung-beetles or Searabceides, the earliest
species of the spring. It belongs to the large family of the
Lamellicornes, having the antennae clubbed and composed
of leaflets arranged like a fan, opening and shutting in the
same manner. The first pair of legs are remarkably strong,
the tibiae toothed for burrowing in the earth and manure
upon which they feed. Many of the species are very large
and beautiful, with metallic bodies and sculptured Elytra.
The Onthophagus is small, but of a brassy black colour ;

78

Objects for the Microscope.

the elytra dull grayish-yellow thickly clouded with black,
and it has a curious pair of horns on its head. The mouth
shows a pair of broad curved and delicately fringed maxillae,
which deserve examination with a high power. The last
joint of the maxillary palpi is the largest, and the labial
palpi are very hairy.

MOUTH OF AECHOMENUS,

a species nearly allied to Brachinus, a small green Beetle
found under stones. We observe the maxillae terminate
in a single hook, with two pair of palpi, and the tongue-
let having the paraglossse mentioned in the mouth of
Brachinus.

MOUTH OF CRIOCERIS.

{Asparagus Beetle.)

This abundant and pretty Beetle is found in the hot sunny
days of July laying eggs upon the asparagus plants. It is
blue and red, with the elytra marked in the form of a double
cross, yellow and blue. It belongs to the order Tetramera ,
having four joints in the tarsi.

The mouth displays a membranous two-lobed tonguelet,
the maxillae whitish and membranous, delicately fringed ;
the terminal lobe straight, the palpi filiform.

MOUTH OF LADYBIRD,

{Coccinella,)

too well known to need description ; but it may be noticed
that it belongs to the last order of Coleoptera, the Trimera ,
having only three joints in the tarsi.

The mouth is very remarkable from the hatchet-shape of
the last joint of the maxillary palpi. The maxillae are
armed on the inner edge with a horny tooth.

When the Coccinella is alive and in its youth, the circu-
lation of blood may be seen in the veins of the wing.

MOUTH OF STENOPTERUS RUFUS.

A black Beetle with red antennae, not common in Eng-

Objects for the Microscope .

79

land ; found in June near Darenth Wood and Coombe
Wood. It is one of the Cerambycidse, a section of the
Longicornes. These have only four joints in the tarsi, the
last three furnished with short brushes, and the first and
second joints heart-shaped. The mouth is very differently
constructed from those before described. The two maxillary
lobes are remarkably distinct and prolonged beyond the
palpi : the last joint of the palpi thick, conical, and dark-
coloured. I may mention here, as Stenopterus is rare in
England, that a very pretty species of the same family may
be readily found on willows, and the mouth will show the
same kind of maxillae, with this one difference in the palpi
— that the maxillary palpi are very much smaller than the
labial , or even the maxillary lobes.

The beetle to which I refer is Cerambyx moschatus , or
Musk-beetle, about an inch long, green, shaded with blue,
or a more golden colour, emitting a scent of musk or of
otto of roses on being handled. It has long antennae, and
kidney-shaped eyes surrounding the base of the antennae.
The larva is a soft white maggot, burrowing under the
bark of trees.

ANTENNA.

The antennae, or feelers, are very important organs in
all insects ; but especially in the flies and beetles. In both
these orders the shape, position, and number of joints in
the antennae, form distinguishing characters in the genera
and species of insects.

They are situated on the head, near the eyes. They
deserve particular attention and study ; for no organs are
more wonderful or more useful, and, until lately, none so
little understood. The order Coleoptera is divided by
them into the families, Lamellicornes, Clavicornes, Serri-
cornes, and Palpicornes. For examples of these, which
are very beautiful, look at the head of the common Dung-
beetle, which has a clubbed antenna, formed of leaflets,
capable of being shut up.

80

Objects for the Microscope.

ANTENNA OF COCKCHAFER,

another Lamellicorne beetle, every leaflet of whose beautiful
antennae shows a cellular tissue of oval cells, with nucleus
and nucleolus, according to Quekett; but with an external
cuticle of hexagonal cells, according to Carpenter. The
organs of sensation, sacs and sacculi, are found in them,
and occupy the place of the nucleoli of Quekett. (See
antennae of Syrphus.) The leaflets of the male are much
longer than those of the female.

ANTENNAE OF NITIDULARIA.

An example of Clavicorne antennae. These Nitidularia
are small beetles which haunt our flowers and swarm upon
nettles all the summer long, and may be recognised by their
antennae having eleven joints, the last three clubbed.

ANTENNAS OF IIYDROPHILUS,

is an example of Palpicome antennae ; clubbed also, but
differently shaped, and having only nine joints— never
more.

antenna: of elater.

Here is a common little beetle, often called Skip-jack,
from its springing up with a jerk when laid on its back ;
easily recognised on plants by its depressed head, and
long dark body; also by its habit of falling down as if
dead when alarmed. The antennae are an example of the
Serricornes , toothed or serrated, especially those of the male
insect.

For examples of variety of antennae in the Diptera, look
at the heads of Dolichopus, Empis, Sepedon, and Syrphus,
Phora, Tabanus, &c. Compare these with the antennae of
Bee, Saw-fly, Ichneumon-fly, and Dragon-fly. The antennae
not only vary in the species, but in the sexes, and are
always most beautiful in the male ; as in the head of a
Gnat, which is plumed, whilst that of the female is quite
plain.

The wild Bees, Saw-flies, and Beetles, present many
examples where the different shape and length of the

Feet of Insects, Petal of Geranium, etc.

Plate 3.

1. Foot of Spider magnified 18 diameters. 2. Claws of Spider, magd. 100 diams.

3. Foot of Fly, magd. 20 diams. 4. Foot of Boatfly, magd. 4 diams.

5. Boatfly. 6, Boatfly floating 7- Boatfly on the wing. 8. Petral of Geranium.

9 Piece of Geranium Petal, magd. 8 diams. 10. Minute portion of Petal, magd. 150 diams.
Pollen of Clarkia pulchella, magd. 100 diameters. 12. Pollen of Crown-imperial, magd. 100 diams.
13. Grain of the above, magd. 300 diams. 14. Pollen of Salvia patens, magd. 100 diams.

Objects for the Microscope.

antennae enable us at first sight to recognise the sex.
Therefore we should study them, especially in the following
insects : —

WILD BEES.

Chelostoma

Specodes

Halictus

Andrena

Eucera

BEETLES.

Cerambyx

Anthrenus

Colymbetes

Scolia

Anthrophila

Rhipicera

Chelonus

Elater

ICHNEUMONS.

Pteronus

MOTHS.

Bombyces

Saturnia

It has been supposed that they were chiefly the organ
of touch, probably of smell also, and of hearing. Certain
it is that they are most important to the insect, and that
special contrivance for their preservation and use may be
observed in many tribes. I will but mention a few exam-
ples. The common Water-scorpions, Nepa and Belastoma,
have very deep kidney-shaped boxes between the eye and
the throat to defend their singular antennae. Cryptocerus,
a remarkable ant, has a square plate, the sides of which
form a longitudinal cavity in which the antennae lie quite
concealed and safe. Many of the Diptera have furrows in
their foreheads, which receive and protect the antennae in
repose. Many beetles, Anthrenus and Byrrhus, have cavi-
ties under the prothorax or breast, where, when alarmed,
their antennae are secreted.

But in proof that they are certainly organs of sensation
in a high degree, it has lately been discovered that the
antennae of Bees, Wasps, Flies, Dragon-flies and Ichneu-
mons have peculiar structures which had never been
described before. Dr. Hicks published his papers on the
subject in the ‘ Transactions of the Linnaean Society,
1857.’

ANTENNAE OF SYRPHUS, OR OF BLOW-FLY.

( Musca Vomitoria.)

Either of these may be taken to illustrate what is stated
by Dr. Hicks. If properly mounted they will be trans-
parent ; and on the third joint of each example will be seen
a multitude of transparent dots. These dots are perfora-

82

Objects for the Microscope.

tions of the inner coat of the wall of the antenna, closed
externally by a very thin membrane. Behind this perfora-
tion is a sac which, when the antenna is crushed or broken
up, may be found floating about in the fluid. There are
about 17,000 of these sacs in each antenna. Besides these
simple sacs there are large spores, which lead into chambers
from which numerous little sacs or sacculi radiate. These
apertures are fringed with very minute hairs. There are
about eighty of these cavities on each side of the antennae.
They are filled with fluid, closed in from the outer air by a
very thin membrane, and to each little sac a nerve proceeds
from the large antennal nerve.

This will be seen better in

ANTENNAL OF BEE.

On the last, three joints of these antennae, but only on one
side, we find these vesicles or sacs ; and if properly pre-
pared the great nerve may be distinctly seen, giving off
three bundles of finer nerves, each of these dots receiving
one.

ANTENNA: OF ICHNEUMON.

One species of Ichneumon will give singularly-shaped
perforations, in which the transparent membrane over-arches
and extends beyond the aperture, and gives it the appearance
of an inverted canoe.

ANTENNAL OF ABGYNNIS.

Argynnis, or Fritillary Butterfly, tawny coloured, with
black lines and spots on the upper wing, and silvery streaks
and spots on the underside of the hind wing. The antenrise
possess small transparent dots and chambered cavities.

PALPI OF ARGYNNIS,

a very pretty object, showing the scales or feathers of the
Butterfly in situ.

antenna; of dragon-fly

furnish the most beautiful examples of these acoustic cham-
bers, and display the nerve well.

Objects for the Microscope.

83

ANTENNiE OF SILKWORM MOTH.

These will form an example of the variation of the An-
tennae in the sexes, those of the male Moth being pecti-
nated throughout equally, while those of the female have
shorter branches, and alternately one long and one short.

To prepare the antennae of Bees, Wasps, and Flies, for
these observations, it is necessary to soak them in chlorate
of potash, with a few drops of hydrochloric acid, until they
are colourless ; then dry them and mount in balsam.

SPIRACLES AND TRACHEA
SPIRACLES OF DYTISCUS.

The Dytiscus is a large Water-beetle, very common in
ditches and ponds, belonging to the pentamerous Coleop-
tera. It passes its first stage of existence wholly in the
water as a most voracious larva, with long narrow body
and strong head, armed with mandibles, breathing by the
anus, and rising frequently to the surface, when it hangs
head downwards and the body curved like an S. When
full-grown as larva it buries itself in the earth, changes to
a pupa, and afterwards to the perfect insect. It is from
the Beetle that these spiracles or breathing organs are
taken.

Few objects are more beautiful than those prepared from
the respiratory apparatus of insects. The blood of insects
is aerated, not by its passing through particular organs, as
the lungs in some land animals, or the gills of fish ; but the
air is circulated in every part of their body by means of
delicate spiral vessels, called tracheae, or air-tubes, which,
ramify into the minutest organs. As you observe these
spiracles, look also at these slides, which are very commonly
found in all collections.

TRACHEAE OF DYTISCUS.

You see they greatly resemble the spiral vessels of plants ;
within the outer membrane an elastic fibre winds round and

84

Objects for the Microscope.

round in close and regular coils, and then comes another
thin transparent membrane, closing it in and securing it
from disturbance. When these tubes are pressed flat and
are large, as the tracheae of Dytiscus, then the double wall
of fibre crossing each other gives an appearance of watered
silk. Vessels such as these in the tongues, wings, and
throughout the body, are easily dissected for examination,
by opening the abdomen and floating off the fine white
threads which branch off on either side from every spiracle.
This brings us back to the spiracle itself, which is on every
segment of the abdomen, an oval opening defended by those
beautiful arborescent hairs, preventing dust or particles of
harmful substance from entering in and lacerating the
delicate tracheal vessels.

SPIRACLES OF COCKCHAFER.

( Melolontha .)

Here is a difference of structure in the spiracles of the
larva of Cockchafer, which burrows in the earth to a great
depth, and whose naked body has no defence for its tracheal
aperture ; therefore the spiracle, though very small, is doubly
protected by a framework of bars, stretched from side to
side of the thickened margin, and a membrane dotted with
minute holes covers these again, effectually protecting the
tracheae, whilst it freely admits the air.

SPIRACLE OF FLY,

is a modification of the spiracle of Dytiscus. It is inter-
laced with branching fibre.

SPIRACLE OF TIPULA.

This has a solid disc in the centre, and radii proceed
from thence to the margin.

SPIRACLES OF WATER LARVAE.

These are best examined in the living larvae of the Gnat,
where the last segment of the abdomen is prolonged into a
tube, the mouth of which remains at the surface of the
water vrhilst the animal breathes.

85

Objects for the Microscope.

There are, however, other and quite different modes of
respiration in aquatic larvae, which form beautiful micro-
scopic objects.

AERATING LEAFLET OF LIBELLULA,

the larva of one of the Dragon-flies, those slender, beau-
tiful blue and scarlet flies, which glance like living sun-
beams across our path on a summer’s day, and may be
found in thousands resting on the reeds and bushes at the
river’s side. When these are in the larval state, they have
three leaflike plates at the extremity of the abdomen, over
which innumerable tracheae ramify and draw from the
water that supply of air which is needful for their life.

ABDOMEN OF EPHEMERA, OR SPIRACLES.

The larva of the pretty May-fly, or Ephemera, has on
either side of its body a row of little leaflets, each of which
is an external spiracle, and when alive it is most interesting
to watch its palpitations, the play of those tiny organs
drawing oxygen from the water to aerate the blood. It is
best thus to see it, because we are able to observe the
circulation of the blood through the transparent skin.

CIRCULATION OF BLOOD.

All creatures that have life have blood : it is the nourish-
ing fluid which is needful for existence. In insects, it is
colourless, but composed of minute corpuscles, which are
propelled through the body, not by arteries and veins, but
by one great dorsal vessel, constricted at intervals, and one
end of which is closed, the other open and acting as the
aorta of the heart. We see it here constricting and dilating,
pumping out the blood which bathes the whole interior of
the body, flowing into the antennse, the legs, the wings —
taking all directions. Here also we see a regular current
through each appendage of the tail, and backward it is drawn
into the long dorsal vessel through some lateral Assures in
it, which are closed by valves, preventing its return. More-
over, we can see in this larva the constrictions of the heart,

86

Objects for the Microscope.

its divisions into parts or chambers, called cardiac chambers,
each of which is closed by a little door or valve, only
opening upwards, so that the onward flow of the blood is
secured, and out it is forced from the aorta again to con-
tinue its circulation. We understand better when we have
watched this in the living creature, how the delicate tracheal
vessels receiving air through the spiracles give it out to the
blood in which they are immersed. Although there are no
distinct membranous veins in insects, yet the blood flows
in regular channels formed by the interstices of the flakes of
fat, air-cells, muscles, &c. The pulsations vary in different
insects. Hunter counted thirty-four pulsations in a minute
in the heart of a silkworm ; which we can do, as the great
dorsal vessel is very distinctly seen constricting and dilating
in the full-grown larva. When excited by fear or muscular
exertion, the action of the heart is accelerated to as many
as 100 and 140 pulsations in a minute.

In examining the larva of Ephemerae, which are abundant
in most ponds, simply confine it in a live box with a drop
of water, and just press it sufficiently to keep it still, yet
unhurt. If you cannot easily find a larva of Ephemerae,
any waterbutt in summer will abound with larvae of Gnat,
and they will do nearly as well. So also will a newly-
hatched Fly, or a young Bee, just before it emerges from
the pupa case ; in these the circulation will be observed in
the wings.

SPIRACLES OF LARVA OF BOT-FLY.

( (Estrus .)

See egg of (Estrus for an account of the Bot.

WINGS OF INSECTS.

There is much to learn in the wings of Coleoptera,
Hemiptera, Hymenoptera, and Diptera. The scales or
feathers which clothe the wings of Lepidoptera are noticed
under Scales of Moth. The Diptera are classed by the
veining of the wings, and therefore it is absolutely necessary
to have a few specimens mounted as lessons for the names
of the nerves or veins of the wing.

Objects for the Microscope . 87

The wing itself may be described as a transparent mem-
branous organ, consisting of two laminae, or plates, which
are united by canals called veins or nerves. These veins
are hollow channels through which the circulating fluid
flows, and a tracheal vessel runs in communication with the
tracheae in the thorax.

In the Ladybird’s ( Coccinella ) wing, the blood is not con-
fined to these canals or veins, but circulates freely through a
large part of the wing. The circulation may be seen in the
wing of any newly-hatched fly, but especially in that of the
beautiful lace-winged fly, Hemerobius, where it was first
noticed by Dr. Bowerbank.

WING OF SCATOPHAGA.

Although this is fully described for the slide of Scato-
phaga, mounted whole, it is mentioned here as the best
lesson on the veins, and very easily put up separately. If
merely mounted dry, the veins are sufficiently seen, but when
soaked for a few days in turpentine and mounted in balsam,
they become transparent from the expulsion of the air ; and
then not only the canals, but the tracheae, may be visible,
especially in the costal vein.

Observe that strong vein bordered with hairs on the
fore-margin of the wing— that is the Costal vein ; and in
the Coleoptera there is inside a little bag of fluid called
the Phialum, by which the fly can, at its pleasure, increase
the weight of its wing, and sink or fly slowly.

The short vein next to the Costal , ending at about one-
third of the length of the wing, is called the Sub-Costal .

The next to that is the Mediastinal.

The next is the Radial , which forks off at its base ; and
the farthest branch is the Cubital , always an important vein.

After the Cubital comes the Prcebrachial, joined to it by a
transverse vein, called the Discal transverse .

WING OF HOUSE-FLY.

(Musca.)

This is an example of the true fly’s wing. The Muscidse
are very numerous, and divided into many groups and

88

Objects for the Microscope.

families ; the third joint of the antennae, always the largest
in this family, enables us to recognise a true Musca at once.
After that we must look at the wing, which varies very
much in the number and position of its veins.

There are many house-flies. The Musca domestica will
show the praebrachial vein, forming a rounded obtuse angle
at its flexure, nearly straight from thence to the tip ; the
discal transverse vein nearly straight, parted from the border
by more than half its length.

This little wing makes 600 strokes a second, carrying it
five yards ; if alarmed, can increase its velocity to thirty-
five feet in a second.

WING OF BLUE-BOTTLE FLY,

{Musca Vomitoria,)

will show the Discal transverse vein with two distinct
curves, parted from the border and from the flexure of the
praebrachial by hardly one-third of its length. The an-
tennae of this fly have the third joint remarkably long, and
furnished with peculiar organs of smell. ( See Antennae of
Blow -fly.)

WING OF SYRPHUS,

not one of the Muscidae, or true flies, and therefore a good
example of a beautiful variety. The Syrphidae are a nu-
merous family, comprising thirty-one genera; they are
mostly seen hovering over flowers, vibrating their wings as
they pause awhile, then darting with rapid flight a short
distance only, and becoming stationary again. Many of
the species make a humming noise like a Bee, and are
mistaken for either Bees or Wasps.

The veining of this wing is an excellent lesson. The
Costal vein ends just before the tip of the wing, and
receives the Radial , or Cubital; for both these veins are
not always present in the Syrphus wing.

The Mediastinal is very distinct ; a transverse vein con-
nects the Cubital with the Prcebrachial near the margin.
But the chief distinction lies in one or two spurious veins,

Seed-vessels of Ferns, and Section of Limestone.

Plate 2.

I. Seed-vessel of Fern when unripe, magnified 00 diameters. 2. Seed-vessel of Fern, at the
moment when the ring straightens itself. 3. Leaflet of Black Maiden-hair Spleenwort Fern.

4. Two sori, or collection of seed-vessels, of Spleenwort Fern, magd. 12 diams. 5. Sorus of
Hart’s-tongue Fern, magd. 6 diams. 6. Part of a leaflet of Shield Fern.

7. Sorus, magd. 10 diams. 8. Sori of Polypody Fern, magd. 7 diams. 9. Sori and part of
leaflet of Hare’s-foot Fern, magd. 5 diams. 10. Thin section of Limestone, magd. 20 diams.

II. Group of twenty seed-vessels, natural size. 12. Group of twenty seed-vessels, magd. 6. diams.

13. Leaflet of Polypody. 14. part of a leaflet of Hare’s-foot Fern.

89

Objects for the Microscope .

one of which crosses a small transverse vein between the
Prcebrachial and Cubital , and the second, when present,
runs behind the Pobrachial vein.

These examples of wings are most useful in awakening
attention to the importance of minute observation, to the
perfect order of Creation in all its parts, to the distinct
individuality of each tiny fly in the presence of Him who
made it. How little we think of this ; how carelessly we
glance at the flies on our window-panes ; they are nearly
all alike to our unseeing eyes. We complain of them, lay
traps for them, kill them, but it seldom occurs to us that
we had better study them.

WING OF MIDGE.

( Psychoda .)

Only two examples more will I give — the wing of a
Midge and the wing of a Gnat. These both belong to the
first order of Diptera, the Tipulidse, which comprises all the
Gnats, Midges, and Daddy-long-legs, or Tipulse. There are
many more veins in this tiny wing than in any yet noticed,
and the number of areolets or enclosed spaces in the wing
is thirteen, every vein thickly covered with fine hairs ;
these are supposed to assist the insect in its downward
flight, by fixing the atmospheric fluid, which glides over it
as they rise.

The motion of a little Midge on the window-pane is
always zigzag, from right to left, and left to right. Some
wings have six or seven spots upon them, and are called
Psychoda sexpunctata .

WING OF GNAT.

This wing differs in the various species of Gnats which
haunt our waterbutts, and tanks, and stagnant ponds.
Some have more beautiful scales than others, but this wing
of the common Gnat (Culex pipiens) is a good study and a
most pleasing object. Look at it with the lowest power
for the veining, and then with the highest for the scales.

The Gnats belong to that division of flies called Tipu-
lidse, and also Nemocera, which means having the head

6

90

Objects for the Microscope .

branched. They all have long and beautiful antennse,
which, in the males, are plumed and whorled like the stems
of Equisetum.

The wings are narrow and lanceolate.

Sub-costal vein ends a little before the tip of the wing.

Radial , branched from the Sub-costal , and is forked.

Cubital vein begins from the Prcebrachial small transvese.

Mediastinal is between the Radial and Costal.

Prcebrachial is also forked. There are fourteen areolets.

The scales of a Gnat form test objects of the defining
power of an object glass. Scales are composed of two or
three layers of membrane, and probably the longitudinal
ridges in these scales may represent folds of the outer
membrane. We should not only see these striae, but the
delicate transverse markings and projections of the lines
beyond the top of the scale.

Gnats fly silently in winter and early spring, before the
thirst for blood is awakened, and then the female only sounds
the shrill clarion of war in her eager flight to and fro. See
the Gnat ( Culex ), mounted whole, and for the complete
knowledge of Flies, consult ‘ Walker’s British Diptera,’
vol. iii. ; ‘ The Xnsecta Britannica.’

WING OF COLEOPTERA.

Beetles have four wings ; but the upper pair, being crusta-
ceous and used only as a protection for the under pair, are
called Elytra. Their use is obvious from the habits of the
Coleoptera ; they burrow in the ground and reside under
the bark of trees, or beneath stones, when the undefended
membranous wing would receive the greatest injury. The
under wing is particularly described when examining the
slide of Telephorus.

Both of these should be mounted and observed. The
upper pair, or Elytra, if properly prepared, are very beau-
tiful polariscope objects, especially those of Dytiscus and
Cockchafer ( Melolontlia ).

But there is a more important notice to be taken of the
internal structure of the Elytron. Dr. Hicks discovered
the same vesicles here as he did in the antennse of Flies

Objects for the Microscope .

91

and Bees. (See Antennae.) The wing-nerve branches
• over the Elytron, and those dots which exhibit the black
cross with polarized light, are vesicles or organs of sensa-
tion, to which a distinct branch of the nerve may be traced.

Soak the Elytron in potash for a week or more, and when
perfectly transparent mount in balsam.

The under wings exhibit groups of these vesicles on the
under side of the sub-costal nerve, as many as 200 and 300
in each wing. Observe the wing of Strangalia, a Longi-
corne Beetle. (See ‘Journal of Linnaean Society/ vol. i.
p. 136, Nov. 1, 1856). See also Elytra of Diamond Beetle.

WING OF CRICKET.

(Acheta domestica.)

This is mounted to show the organ of sound, the drum
and file by which the male Cricket chirps. Each of the
upper wings, or Elytra, has a round transparent space called
the drum, or tympanum ; at the base of each Elytron is a
transverse horny ridge, furnished with numerous short
transverse ridges or teeth, and forming a kind of bow or
file. The insect rubs the Elytra across one another, and
the grating of the files, together with the action of the
drum as a sounding-board, causes the loud chirp. Some
naturalists think that the legs work against this file and
produce the sound, particularly in the Grasshopper, whose
thighs are armed with rough ridges and short spines, and
act as the bow against the files and drum of the Elytra.

The male Cricket only chirps. The female, silently at
home, occupies herself in laying about 300 eggs and in
rearing her brood. The tongue of a cricket is a beautiful
object.

SCALES OF INSECTS.

The feathers of a Moth, a Butterfly, a Gnat, the scales
of a Beetle, of a Weevil, of the Podura, are all both favourite
and useful objects for the microscope. It is well known to
every one that the dust which remains on our fingers after
touching a butterfly’s wing is a mass of beautiful feathers,

9 2

Objects for the Microscope .

or scales, varying in shape and colour with the species ;
and that some are so delicately ornamented with a tracery
that no unassisted eye can see that they form test objects
for the defining power of the microscope.

Besides that use, we learn much from viewing a part of
a butterfly’s wing as an opaque, and observing how the
scales are arranged on the membrane of the wing exactly
like the tiles on the roof of a house ; — this is called being
“ imbricated each scale furnished with a point at one
end which fits into a cup -like socket, attached to the skin
of the body or the membrane of the wing. When the scales
are rubbed off and transparent, we can better observe their
structure, and we have some excellent examples in the
slides numbered here.

SCALES OF MORPHO MENELAUS.

Each scale or feather consists of three distinct laminae,
two external and coloured, the inner one a highly polished
colourless membrane, which reflects the light and increases
the brilliancy of the scale. The Morpho menelaus, a large
foreign butterfly of gorgeous blue, has striated scales, and
with very high power, each line is slightly beaded, giving
the appearance of transverse scoriae ; but to see this the
achromatic condenser must be used.

SCALES OF POLYOMMATUS ARGUS,

a British Butterfly common as the pretty blue butterfly of
the cornfield, or the seaside Downs ; has peculiar scales
shaped like a battledore with long handle, and the longi-
tudinal lines are swollen at intervals into rounded eleva-
tions, which give it a dotted appearance, except towards
the base, where a crescent- shaped cloud of minute pigment-
cells crosses the scale, and forms a distinguishing mark of
the species.

SCALES OF HIPPARCHIA JANIRA,

our little meadow brown Butterfly, which flits so merrily
about the long grass in June to October, laying its exqui-
site eggs upon the stems, from which a green striped
caterpillar emerges in due time. These are the scales of

Objects for the Microscope.

93

its brown wings, most excellent test objects, and giving
different markings. When dry, or in balsam, or when
viewed by oblique or direct light, w'e see that the rounded
end is toothed, and bears a brush-shaped appendage.

SCALES OF PONTIA BRASSICA.

The common Cabbage Butterfly, whose history is too
well known to need remark ; the earliest and latest of our
summer friends and garden enemies. There are several
shapes in the scales of its wing, a very long and slender one,
and some more of the battledore shape, and heart-shaped,
with beautiful strise. Observe also a portion of the mem-
brane, where the scales or feathers are rubbed off. The
apertures into which they are fixed are little cups or tubes,
the orifices of which are set backward ; and around each
are radiating folds of the upper membrane, giving them a
star-like appearance.

SCALES OF THE SILKWORM MOTH.

The Silkworm Moth ( Bornbyx mor'i) has a variety of
scales, toothed, and broad or narrow, and Leuwenhoeck
reckoned no less than 400,000 of these delicate scales on
the wings of one moth.

SCALES OF CLOTHES MOTH.

From the under side of that troublesome little Tinea we
obtain a beautiful test object of very fine striae. Also from
the Podura.

SCALES OF PODURA.

The Podura is a small gray wingless insect with six legs,
and a long forked tail, bent inwards, and by means of
which it leaps and springs about in the sawdust of our
cellars, and under stones, and in moss in damp places.

SCALES OF LEPISMA SACCHARINA.

A first cousin of Podura, haunting our sugar stores, and
originally a native of America. It does not leap so well as
Podura, if at all ; for its body does not terminate in a forked
tail, but in several long thread-like styles, and it runs
swiftly along, the little silvery gray body closely covered

94

Objects for the Microscope.

with these beautiful scales which require high and good
powers to see distinctly.

A few words may be added on the appearance which
Podura scales should present as a test object. Under a
medium power they resemble watered silk ; light and dark
lines wave across the scale in irregular bands ; but with
better definition every dark band should be resolved into
rows of short lines, thick at one end, and very tine at the
other. Yet these apparent lines are not lines. We must
have a higher power, a good quarter-inch lens, and then
with careful management of light — always a most impor-
tant thing — we shall see that the apparent lines are really
spaces between the wedge-like particles which make up
the layer or upper surface of the scale. As a test object it
is out of fashion ; the dots of the Pleurosigma and the strise
of Grammatophora and Pygidium of a flea being preferred
by many scientific observers.

ELYTRON OF DIAMOND BEETLE.

A most beautiful object, to be looked at with reflected
light — that is as an opaque. These brilliant spots are
groups of scales, fashioned precisely like those of a butterfly’s
wing, but owing to their iridescence, to the peculiar thinness
of the upper layer and the reflecting power of the secon-
dary layer, the colour changes like that on a soap-bubble
by the varied position of the light, the dark cell in which
the scales are set adding to their brilliancy. The Diamond
Beetle is one of the weevil tribe, and a native of South
America; but we have smaller Diamond Beetles in our
own country, and the Curculio of the oak and of the beech,
a little green and gold weevil, by no means rare on nettle-
plants, is quite as beautiful under the microscope, having
the same kind of scales, set in dark cup-like recesses on
its elytra.

FEET AND LEGS OF INSECTS.

FOOT OF SYRPHUS.

Although the feet are better studied with the leg and
upon the whole insect, yet as those specimens are not so

95

Objects for the Microscope.

easily obtained as the foot of Syrphus, it should by all
means form part of an educational box.

The Syrphus is one of those flies which vibrate over our
flowers in the summer, and haunt the Michaelmas Daisy
in the autumn. They are called Drone-flies and Wasp-
flies, and are mistaken sometimes for one of the Hyme-
noptera.

This foot displays that pair of membranous expansions
called pulvilli which enable the fly to walk up and down
smooth surfaces, on glass and on ceilings, in opposition to
the laws of gravity. They are fringed with minute hairs,
each of which is tubular, and secretes a viscid fluid which
attaches the foot to the surface of the glass or wall, and the
hooks on either side act as fulcra or props, with which the
fly pushes against the substance when it desires to detach
itself. The joints above the pulvilli are called tarsi.

LEG OF DYTISCUS, OR DYTICUS.

A most splendid object for the polariscope. The Dytiscus
is a large water-beetle, common in ditches and ponds, and
this is the fore-leg of the male. That large round disc is
composed of three joints of the tarsi, which are studded
with suckers ; one is extremely large, furnished with radi-
ating fibres, and another is somewhat smaller, with single
cup-like suckers raised on stalks, altogether giving it an
immense power of adhesion.

FOOT OF WASP,

another favourite object for the polariscope : the tarsal
joints are well seen, as also the hooks on each side of the
pulvillus.

FOOT OF OPHION.

These toothed claws belong to an Ichneumon-fly (Ophion),
which deposits its eggs in the larva or caterpillar of a moth
( Bombyx Vinula, Puss Moth). The fly is yellow and has a
sickle-shaped body, the ovipositor slightly exserted. — ( See
Hymenoptera Microgaster.)

96

Objects for the Microscope .

IIIND-LEGr OF BEE.

This is to show the peculiar structure of the hind-leg of
the Hive-bee. The worker-bee— not the queen, nor yet
the drone — has this beautiful contrivance for gathering the
bee-bread, and carrying it home to the hive. The Bee
collects the pollen of flowers, and rolls it into little pellets,
which she places in two hollows on the outside ot her hind-
legs, called the baskets. This is done by her mouth and
these hairy legs, which help to collect the pollen, and work
it into shape and consistence.

Every leg has ten rows of these hairs, and sixteen hairs
in a row. Count them, and observe how short and stiff
they are, exactly what the Bee wants for her work.

FOEE-LEG OF BEE.

The fore-legs of the Hive-bee, or Carder, or Humble-bee,
exhibit a peculiar notch and spur on the tibia, which the
insect uses for clinging each to the other in the festoons
of wax-secreting labourers, or for nipping the legs of an
enemy. There is a deep notch edged with stiff short
bristles, and above it a spur, fashioned somewhat like the
blade of a pocket-knife, which closes over it, and must be a
most useful appendage to the busy Carder-bee in hackling
its moss. It must not be soaked long in potash or the
spur falls off. Mounted dry for the binocular it is well
seen, and the modifications adapted to each species are
very interesting.

LEG OF GYEINUS.

The Gyrinus is a small Water-beetle, that merry little
fellow who assembles with a host of comrades, whirls round
in ceaseless play on the surface of the quiet pond, or sunny
margin of the river. Boys call it the Whirligig Beetle.
These curious hind-legs, of which he has four, are the oars
and helm by which he propels and steers his little body
with such velocity through the water.

The structure is remarkable, the femur and tibia are
somewhat triangular, the latter fringed with short spines,
and long flattened filaments ; in the middle pair of legs

97

Objects for the Microscope.

these filaments are on both margins, on the hindmost only
on the outer margin.

The tarsi are five-jointed, but the three upper ones are
most curiously fashioned into long leaf-like lobes, fringed
with spines, the fourth joint is about the same size and
semi-circular, and the fifth very short-armed, with two
claws, as indeed is each tarsal joint.

Circulating currents may be seen in the hind-legs. Also,
if you catch one, examine its very curious eyes divided into
two parts, the upper group for viewing objects in the air,
and the lower those in the water. The antennae are remark-
able, not only in shape, but in being retractile and having
each an ear-like joint fringed with colourless flat hairs, which
shuts it into the cavity in front of the eyes.

LEG OF BRACHINUS.

( Bombadier Beetle.)

A small red and black Beetle, common near London,
which has the power of defending itself by letting off smoke
with the noise of a pop-gun. It is furnished with an internal
bladder capable of firing off twenty shots in succession. If
this smoke gets into the eyes it makes them smart as if
they had been bathed with brandy. This little fellow has a
bitter enemy in the Calamosa, a larger beetle, which hunts it
without mercy. As it finds it impossible to escape by speed
of foot, it stops short and awaits its pursuer ; but just as
he is about to seize it, he is saluted by a discharge, and
while he is for a moment stupefied with surprise, the
bombadier endeavours to gain a hiding place. — ( See ‘ Insect
Miscellanies’; also Bouche de Brachinus, in Baker’s col-
lection.)

LEG OF ANCHOMENUS,

a small green Beetle, nearly allied to Brachinus, as the
leg will show ; both of them have that very curious curve
in the tibia which is peculiar to the Carabici. These are
swift-running beetles, and many of them have no wings
under their elytra : they belong to the Pentamera, having
five tarsi or ankle-joints. — (See also Bouche et Palpes, in
Baker’s collection.)

98

Objects for the Microscope .

LEG OF CALATHUS CASTELLOIDES.

A very abundant and pretty Beetle about half an inch
long, black or brown, with black, or sometimes red legs.
Found under stones near London. It has five joints in
the tarsi, therefore belongs to the first order of Coleoptera,
the Pentamera. The claws are toothed like a comb,
and the male has three joints of the anterior tarsi dilated.
(See also Bouche et Palpes de Calathus, in Baker’s col-
lection.)

STING OF WASP AND BEE.

The weapon of defence given to these insects consists of
a barbed dart and a bag of subtle poison. The dart itself
is composed of two blades, with serrated edges, enclosed in
a sheath, and attached by strong muscles to the side of the
abdomen ; near the slit by which it protrudes are two hairy
appendages, which act as brushes and keep it clean, and at
a short distance within a slender canal leads to the bag of
poison, which, pressed by the muscles in the act of stinging,
gives out the acrid drop which irritates the wound to such
painful swelling.

STING OF GNAT.

See Head of Gnat.

STING OF TABANUS.

See Head of Tabanus.

EGG OF BOT-FLY, OR (ESTRUS.

There is not a more curious and interesting object than
this. Those little spots which cover the fore-legs of horses
from the latter end of July to the end of September, are
eggs like this, deposited by a fly called GEstrus, or Gad-fly.
The longest period of this fly’s life is passed in the intes-
tines of the horse, and all the winter every horse exposed
by field work or pasture feeding to the attacks of the
CEstrus is full of the larvae which hatch from this egg.

The fly itself appears only in July, and is properly called

99

Objects for the Microscope.

Gasterophilus, or Stomach-lover. A tawny body very hairy,
wings dingy white, and with a transverse gray band ; with-
out any proboscis, for it lives but a very short time — only
to lay its eggs and die. The abdomen is bent inwards, the
female having a retractile tube consisting of four pieces,
and terminating in five points, within which she holds the
egg, and hovers over the horse, lightly darting at him,
and depositing each egg upon a hair. This egg is firmly
attached by some glutinous substance, and is, as you may
observe, finely striated and furnished with an operculum or
lid, hinged and fitted on that oblique top. When the larva
is fully formed, the egg, which is always placed where the
horse most frequently licks itself, opens under the warm
moisture of the tongue, and the larva, which is provided
with hooks for the purpose, clings to the tongue, and is
swallowed with the saliva or the food. By two long sharp
hooks you may see folded downwards on the larva it attaches
itself to the inner coat of the horse’s stomach, nourished
by the warmth and the mucus until the spring, when it has
grown nearly an inch long ; it then unhooks itself, mingles
with the food, and passes out as what grooms call bots.
The next change is that it wriggles into the earth, and
becomes a pupa, lies there a few weeks, and comes forth as
a perfect fly, to rise up and seek its mate, who dies imme-
diately after their union, and the female lingers but a few
flays longer, to deposit a hundred eggs, or more, as her
appointed task on earth.

100

Objects for the Microscope.

CHAPTER III.

INSECTS MOUNTED WHOLE.

COLEOPTERA, HEMIPT. HYMEN OPT., as C. iv. DIPTERA.

Hitherto we have only examined parts of various
insects, and whilst they have surprised and delighted us by
their curious or beautiful forms, and shown us how perfectly
they are adapted to the wants of each insect ; yet we have
but a very imperfect idea of the anatomy of any single
insect without one of these beautiful preparations.

They cost years of thought and experience to bring to
this perfection. To preserve the delicate body entire, yet
make it perfectly transparent, so as to display every joint,
and in many cases its internal muscular structure ; to fix
it in its natural position, and embalm it, as it were, in the
clear preservative medium, Canada balsam ; to draw out
the beautiful tongue, or the wonderful ovipositor, and show
the varied and fragile antennae, or lay out the fine tissue
of the wings, was the work of many a day before this art
was attained.

And these slides are so valuable to the young student of
natural history that no microscope box should be without
one or two illustrations of each of these orders — Coleoptera,
Hemiptera, Hymenoptera, and Diptera.

No engraving can teach the lesson upon insect anatomy
so well as that which is learnt at the microscope with one
of these slides upon the stage.

Take, for instance, one of the Coleoptera —

THE TELEPHORUS, OR SOLDIER-BEETLE.

We find this little creature abundantly in our gardens, on
hedges, and on the long grass of a sunny June morning ;
but especially on the flowers of all Umbelliferse, such as

101

Objects jor the Microscope.

the wild Parsnip, Carrot, and Parsley. They have orange-
coloured elytra, or green or buff, tipped with red. Chil-
dren call them “ soldiers” and “ sailors.” Carnivorous in
their tastes, they haunt flowers for the smaller insects they
feed upon, and seize them fiercely in their strong pointed
mandibles. When we touch them they depress their heads,
become motionless, and counterfeit death.

They lay their eggs in damp shady places in the earth,
where the larvae hatch and live. These are velvety, black,
long, soft-bodied maggots, with strong mandibles on their
heads, and a curious Seshy tubercle beneath the last segment
of the body, which they use in walking.

Use your lowest power in examining these preparations
for a general view of the insect, and then change the object
glass progressively upward to the highest power for such
parts as require particular attention — the tongue, the
eye, &c.

The first part to look at in a slide of Coleoptera is the
foot, because the number of joints immediately above
the claw, which are called tarsi, determines its position in
the family group. All the Beetle tribe are divided into
families according to the number of joints of their tarsi.
There are four sections —

The Pentamera . or five-jointed.

The Heteromera . or five-jointed anterior, and four-

jointed posterior tarsi.

The Tetramera . or four joints to all the tarsi.

The Trimera . . or three-jointed tarsi.

The foot of Telephorus, having five joints, belongs to
the first section. Observe how deeply the penultimate joint
is bilobed — that the tibia or joint above the tarsi has two
small spurs— that th q femur or thigh is stout, and attached
to the thorax by two other joints called the coxa and the
trochanter.

Next observe the antennae ; for after deciding this little
beetle to belong to the section of the Pentamera, you will
know that it is also one of the Serricornes, or third family

102

Objects for the Microscope.

of the Pentamera, by its long slender eleven-jointed antennse
of the same thickness throughout.

Next examine the curious hatchet-shaped joint at the
end of the palpi — small feelers attached to the jaws,
and which are very important points for observation, as
their number and shape determine the species of many
beetles.

We now see the various parts of the mouth — the labrum
or lip notched in front ; the two hairy maxillce formed of
five pieces delicately fringed, and used for cleansing the
food ; two strong mandibles or jaws for seizing their prey.

Two compound eyes which, in the male, occupy nearly
the whole of the head.

The thorax, or body, to which are attached the three
pairs of legs, and the wings and wing-cases.

This thorax is a wonderful piece of mechanism. It
cannot be so well seen in this slide, because the elytra or
wing-cases partly cover it ; but it should be carefully studied
in various specimens. There are three chief parts—

The pro-thorax ; the segment nearest the heart, and
supporting the first pair of legs.

The meso-thorax : bearing the elytra, or wing-cases, and
the middle pair of legs.

The meta-thorax ; bearing the wings and the last pair of
legs.

But these are again composed of no less than twenty-
two smaller pieces, equally distinct and present in the thorax
of the tiniest beetle ; and if we consider the complicated
machinery necessary for the direction and control of all the
muscles required for insect locomotion, the care bestowed
upon the formation of the thorax will be at once accounted
for. The movement of the legs in running, creeping,
climbing, swimming, fighting, seizing their prey, cleansing
their bodies, and the varied motions of the wings and
wing-cases — these all demand distinct muscles and points
of attachment. The whole cavity of the thorax is occupied
by the wing and leg muscles, and the great ganglion of
nerve which directs them as a viceregent from the seat of
sensation, the head.

Objects for the Microscope.

103

And whilst looking at the thorax of this little Beetle, as
hereafter we may look at that of a Fly, it will not lessen
our pleasure to be reminded of the many kinds of muscles
that worked unerringly the will of this small creature. It
had its levator muscles for raising its limbs ; depressors ,
antagonistic to these, for depressing them ; flexors for bend-
ing the joints ; extensors for unbending or extending them ;
abductors for drawing an organ backward, and abductors
for drawing it forward ; constrictors that contract a body or
an opening as in breathing ; laxators that relax it. All
these are in quick action in the little insect that runs over
your hand or escapes from your eye ; all these have been
planned and attached, and the numbers so accurately inter-
woven, that they work without hindrance or confusion by
the creative word of the Most High.

As the head for sensation, with its ganglion and branch-
ing nerves, and the thorax for locomotion, so the abdomen,
usually in nine segments, is appointed as the digester of
food and the organ of generation.

The internal parts of an insect cannot be seen in these
preparations. We must therefore confine our attention
to the external anatomy, and, before this slide is put away,
examine the wing.

The wing of a Beetle should be compared with that of a
Fly, in order to appreciate its peculiar structure. The
substance is membranous, double and joined together by
canals or nervures, through which the blood circulates — a
tracheal vessel runs, and a nerve, branching from the
thoracic ganglion, and giving off innumerable fibres to
groups of vesicles situated immediately beneath the costal
nerve. This is only seen with very high powers and good
glasses ; also requiring a particular preparation of the wing.
It must simply be soaked in turpentine for a week or more,
and mounted in balsam warmed just enough to receive the
wing, when the tracheal vessel, the nerve, and the vesicles,
may be distinctly seen with a good J-in. or j~in. object
glass.

That strong nerve on the forepart of the wing is the
costal nerve. As the Beetle’s wing is folded under the

104

Objects for the Microscope.

elytron when in repose, the costal nerve ends abruptly, as
we see, at about half the length of the wing, and turning
backward into the post-costal nervure, forms a kind of
hook, strengthens the base, and allows of the easy folding
up of the tip of the wing.

There is a particular provision made for the regulation
of the specific weight of the beetle’s wing by means of a
long pocket just under the costal and mediastinal nervures,
called the Phialum, into which a liquid is introduced at the
will of the insect, which augments its powers of resistance
in flight.

The veins, or nervures, are so placed throughout this
wing as to strengthen and stretch every part : at the same
time to admit of its being closely and easily folded under
the protecting elytron ; a most necessary arrangement for
creatures who live in the earth or under stones, or in the
water, where the delicate texture of the wing would be in
constant danger of destruction.

Having thus examined one specimen of the Beetle tribe,
we shall be able with increased interest to look at another,
one of the small Water-beetles.

HELOPHORUS GRANULARIS.

This is an abundant little creature in our ponds and
ditches, feeding on decayed or vegetable matter, and, being
easily procured, is selected as an example of a Pentamerous
Coleoptera, but of the family of the Palpicornes, the
antennae being very different from those of the Telephorus.
These are clubbed, composed of nine joints, and carried
backwards.

It is a bad swimmer, and the legs are scarcely, if at all,
feathered ; the striped pro-thorax and the beautifully
dotted elytra make it a favourite and valuable object.

The sculpture of the elytra of Beetles is most remark-
able ; the ridges strengthen, the furrows lighten, the dots
give air to the spiracles beneath. In the Helophorus
alternate rows of large and small dots answer both pur-
poses, and usefulness as well as beauty write the wisdom of
God upon the wing-case of this little creature.

105

B’HAM. FIELD

igbeth W8TITU Objects for the Microscope.

CLUB LIBRARY.

CATHERETES URTIC^.

This is a lovely little Beetle ; as we see by its tarsi, it
is one of the Pentamera, though at first sight easily mis-
taken for one of the four-jointed Coleoptera, as the fifth
joint is very small, and only visible from beneath. The
antennae show that it belongs to the Glavicorne family, for
they are clubbed. This particular little Beetle is one of a
flower-loving group called Nitidulidce, always easily recog-
nised by having eleven joints in the antennae, and the last
three in a club, or strung like beads, with an interval
between each. The spotted elytra are beautiful. The
facetted eyes and the delicate mouth will require a higher
power rightly to examine them. And this exquisite^insect
is one we may see in swarms upon nettles revelling in the
pendent blossoms any sunny summer’s day — very small
black creeping things we pass unheeded by.

COCCINELLA, OR LADY-BIRD.

This familiar little visitor is not only a beautiful object
for the microscope, but a real friend to the florist, who is
apt to be disappointed and angered by what is called
the “ green blight ” upon the roses, and is not perhaps
aware that two or three Lady-birds would clear it all
away much better than the usual means applied by
gardeners.

The Lady-bird is particularly fond of Aphides, and, in
its larva state, pupa state, and perfect form, will greedily
devour them, darting at an Aphis, and seizing it in those
strong little jaws, shaking it as a terrier does a rat, and
sucking its life away ; then dropping the empty body, and
springing upon another and another. The little Coccinella
has frequently saved our fir plantations from the host of
destroying Aphis in the spring ; and our bean-fields, when
attacked by the black blight ( Aphis faboa ), are often
cleared again in an incredibly short time by the avenger
God has given us in this lovely little Beetle.

It is one of the Trimera, three joints only in the tarsi.

7

106

Objects for the Microscope .

The antennse eleven-jointed, and terminated by a reversed
conical club.

I must not describe so fully any more of these beautiful
slides ; but recommend you, if possible, to obtain the
following whole mounted Coleoptera :

Loecophilus Minutas , remarkable for its feathered legs.
Hattica , or Turnip-fly, ,, ,, thick muscular

thighs for leaping.

Thyanus , or Grass-flea, also with muscular thighs and
sculptured elytra,
one of the Tetramera, with thick-
ened thighs and beautiful head,
one of the Hydrocantheri, or
Swimmers, with beautifully fringed
legs for swimming,
one of the Water-beetles, with
fringed legs for swimming, and a
curious spine at the tip of each
elytron.

a Water-beetle. (This is described
in leg of Gyrinus.)

Dimonia cynoglossi .
Haliplus confirms .

Hyphidius ovatus .

Oyrinus natator

HEMIPTERA.

These are sucking insects. Their mouth has a long
retractile tube, and several flne lancets, forming a long pro-
boscis, which is laid along the breast during repose, and
maybe seen in all the Field-bugs ( Cimex ) and the Aphides,
which belong to this order. The wings are membranous,
and covered with semi-transparent cases analogous to the
elytra of Beetles. The tarsi are always three-jointed. A
few of them inhabit the water, and of these the Velia rivu-
lorum and Notonecta are mounted whole.

VELIA EIVULORUM.

Most people have observed groups of water insects
sporting on the surface of small ponds, or swimming

107

Objects for the Microscope.

against small streams, walking lightly on the still water,
and resting on the stems of grass or water weeds around.
One species (Gerris) has a long thin black body and very
long legs ; but Yelia may be known by its scarlet spots on
each side of its body. The two-jointed sucker and the
wing-cases should be carefully examined.

NOTONECTA, OR THE WATER-BOATMAN,

is a beautiful preparation, exhibiting the retractile sucker,
which is a formidable weapon, and pricks sharply; the
eyes very large ; the hind-legs fringed with long hairs and
in the form of oars, which it uses with great rapidity,
rowing or swimming always on the back, and looking like
a canoe propelled by a clever boatman. The eggs of this
insect are found abundantly on the other side of Water-
lily leaves, or of Potomageton ; small flask-like eggs
through which, in an advanced state, the red eyes of the
little Notonecta may be seen, and when it comes forth, it
only resembles its parent in its feathered legs and quick
movements, having no wings until it has moulted several
times, and changed from the larva to the pupa state, in
which, however, it is by no means inactive, for the pupa
of Hemiptera feeds as heartily as the perfect insect. This
Notonecta is a fierce and powerful enemy to all smaller
aquatic insects, transfixing them with his sharp proboscis,
and sucking their life away.

REDUVIUS, OR BED-BUG,

is one of this order, and the sucker, though short, is very
strong, and capable of producing much pain.

CIMEX, OR FIELD-BUG.

These are beautiful objects when mounted. The head is
prolonged like a snout, more or less triangular ; and the
sheath of the sucker is composed of four distinct joints ;
they prey upon other insects ; the body is often brightly
coloured and spotted. We find them abundantly on long
grass or field flowers in the hot days of summer, and one

108 Objects for the Microscope .

species, Pentatoma griseus, is interesting from the care which
the female takes of her young, not only in brooding over
her eggs, but in leading her little family about as a hen
does her chickens.

aphis.

A specimen of the green or black blight will be very
interesting to the florist, although the Aphis of the elder
or the box. are prettier in having variegated bodies. There
are no less than 160 known species, and few insects have a
more curious and interesting biography. ‘ Kirby and
Spence’s Entomology,’ and 4’Histoire des Hemipteres, de
MM. Serville and Amyot,’ will give abundant information
to the student of natural history.

I can only draw attention to the external form, and point
out the remarkable long antennae thrown backwards ; the
proboscis, fine and sharp, with which it pierces the young
shoots of our rose-trees, or the fibres on the under side of
our currant-trees and vines, causing them to curl up and
turn red. Those two horns on the back are tubes from
which exude small drops of saccharine matter or honey-
dew, of which the ants are so fond that, wherever these
Aphides abound, there the Garden Ant will follow, and
may be seen sucking it from them.

These Ants take absolute possession of some species.

The Aphis radicum, which feed on the roots of plants, are
kept by the Yellow Ants in their formicaries under-ground,
and milked as cows are by us. This may be watched on
rose-trees or oak-trees, the little Ants following an Aphis,
tapping them, and pressing their sides to make them jerk
out the sweet fluid.

The tarsi are only two-jointed, the eyes compound.
They are both winged and wingless, and the Aphis wings
are always carried with the fan edges upward, and have
either a row of hooklets or a tuft of seven or eight hooks,
which attach the wing-case and wing together, like the
hamuli of the Hymenoptera.

The rapid increase of these insects is astonishing : a
single Aphis may in one season become the parent of as

Objects for the Microscope.

109

many as 5,904,900,000 descendants. The fact that these
are produced by females without more than one impregna-
tion throughout nine generations long perplexed our natu-
ralists. Bonnet isolated females most carefully, and obtained
nine generations in three months. It is now ascertained
that certain females couple and lay eggs only in the
autumn, and that throughout spring and summer the young
ones are produced alive by a process of gemmation from
what are called Nurses.

All through the winter one solitary female Aphis, which
I had placed in my bedroom window on the leaf of a tulip,
continued to present me with pretty little pink-eyed stag-
gering things, until the whole plant was covered with them ;
and very curious it was to see the small Aphis keep close
to its mother’s side for some hours, whilst she seemed
tenderly to caress it with her long antennae, until another
required her care, and this one was able to join the group
of sisters at a little distance, whose tiny suckers were
plunged into the juices of my Van Tromp.

For an account of their enemies and our avengers, see
Hymenoptera, Aphidius arena.

APHROPHORA, OR CUCKOO-SPIT.

I suppose all florists will like to have this slide, because
they so well know a certain frothy substance which abounds
on their Carnation plants, Lychnis, Rose-trees, and Willows,
in which sits a little green creature with red eyes ; a soft,
frightened, innocent-looking little larva, which I never could
help covering again with the white froth if I had blown it
aside for a moment. And this was the defence of the young
Aphrophora we are now looking at : it passed from that
larva into a pupa, and then into this perfect state with wings
and wing-cases, with a long sucking tube, which pierced the
stems of our flowers and dried up the plant by abstracting
the sweet fluids needful to its growth. Observe the mottled
wing-case, all of uniform texture, which shows it to belong
to the second division of Hemiptera, called Homoptera ; the
wing with longitudinal nerves forked at the tip. The legs,
which leap wonderfully high, are remarkably circled at each

110

Objects for the Microscope.

tibia by a crown of spines. The mouth is better displayed
in a specimen of Cimex.

THRIPS.

This is not now one of the Hemiptera, but belongs to a
very small order called Thysanoptera. We find these very
minute insects swarming in our flowers, especially in the
Carnations and Lilies. They are long, black, active little
creatures, looking like small beetles, and turn up their tails
in a quick impatient way that reminds us of the Staphy-
linus, so fragile that we cannot handle them, except when
mounted thus.

The short antennse we see have eight joints, the terminal
joints armed with a seta. There are four wings of equal
size deeply fringed with hairs on all sides, and usually un-
noticed, because they lie horizontally upon the back, and we
seldom see them in use. The tarsi are short, and terminated
by a vesicle instead of a claw. The mouth has mandibles
and palpi, as well as a rostrum, or beak, with which it
pierces the delicate young leaves of our Cucumbers, Melons,
Vines, and fruit-trees, causing them to shrivel up. They
also feed upon the pollen and pistil of the blossom, and often
cause the failure of our fruit, and of the wheat crop, by
creeping in between the valves of the green ear. Earwigs
avenge us by preying upon them, which florists would do
well to remember when they accuse the earwig of the
destruction of them Carnations.

HYMENOPTERA.

TENTHREDO, OR SAW-FLY.

Sometimes we find “ the saws ” only of this curious fly
mounted for the microscope ; but at Baker’s, and Smith and
Beck’s, you will doubtless obtain the whole insect beauti-
fully prepared, and it is worth any money in the naturalist’s
collection, both as an example of the Hymenoptera wing and
head, and also for its complicated and wonderful ovipositor.
Few of the Hymenoptera can be mounted whole, for the
order comprises all our Bees, Wasps, Ants, Saw-flies,

Ill

Objects for the Microscope.

Ichneumon-flies, and Gall-flies. It is a most interesting
group in the insect world, extremely intelligent, and com-
missioned by its Creator to minister to our comfort and to
defend us from injury in a way that is little known beyond
the labours of the Honey-bee.

The Hymenoptera are distinguished from all those which
are called flies, by having four wings instead of two,
wholly membranous, veined, and divided into cells, but not
assuming the appearance of network, as do those of the
Dragon-fly, the Hemerobius, the Ephemera, or May-fly ;
neither are they veined at all like the wings of the real
fly ( Diptera ), — yet the plan is perfect, both to distinguish
the group, and in that group the species from each other, as
we shall presently prove. The eyes are large and compound
in all the Hymenoptera ; they have generally three simple
eyes, or ocelli, on the crown of the head ; the jaws are
strong ; the tongue of varied structure ( see Tongue of Bee
and Wasp), because the mouth organs are used not only
for food, but also for labour in the structure of nests, and
in providing for their young. The feet are somewhat like
those of the Diptera, but are sometimes terminated by
toothed claws ( see Foot of Ophion) ; the tibia are often
armed with spines, or very curious spur-like appendages,
especially in these Saw-flies, and the tarsi are five-jointed.
As a rule they all feed upon flowers, but I have found them
very voraciously attacking insects in the hot sunshine of a
June morning.

Their metamorphosis is complete ; that is, they lay eggs,
become larvae with six-hooked feet, spin a cocoon, and
change to pupa ; then rise up and go forth winged and
perfect.

The wing of the Hymenoptera is the most important
part in ascertaining the genera, for all the antennae are
long, varying from thirteen joints to as many as sixty or
seventy. They vibrate with singular sensitiveness, but are
not like those of the Diptera, where the antennae alone will
often decide a fly, and the minute differences of their struc-
ture is in itself a study.

Here the index to God’s order is in the wing, and if the

112

Objects for the Microscope .

wings of your specimen are crumpled, as often happens
when the chief anxiety is to show the saws of the fe-
male, then you had better get a male Saw-fly ( Cypheus
pigmmts), where I doubt not they will be expanded and
perfect.

The first great rule is this : look at the costal nerve which
bounds the fore part of every wing, and is the main support.
Observe in all the Saw-flies and Ichneumons there is a dark
horny spot called the stigma ; from that a nerve or vein runs
to the front tip of the wing, dividing the enclosure into
one or two cells, called the marginal or radial cells. There
is but one in Cypheus — a large oblong one. Behind this
cell, and running nearly parallel at a little distance, is a
nerve which ends at the tip of the wing, and the inter-
mediate space is divided into from one to four cells, called
the submarginal or sub- cubital cells, others in the centre are
called discoidal cells, and others, long and narrow towards
the base, are basal cells ; but the two former are those upon
which the genera are founded. Is it not wonderful — this
invariable order exhibited by the presence or absence of one
tiny nerve ? — always present in every individual of a given
species throughout the world ; varied perhaps slightly, yet
unerringly in the adjacent species ; and the progress of
neuration designates the rank of the species more easily
in this than in any other tribe of insects. The little Platy-
gaster, a very small Ichneumon-fly, which is noticed pre-
sently, has only the costal nerve and stigma — no cells at all.
The pretty Chrysides, those scarlet and green or blue flies,
which rush about restlessly on windows and walls in the
hot sun, and are called the Humming-birds of insects, have
only the front wings veined, and those with but a single
cubital cell, and that not closed, and very imperfect sub-
marginal ones. And then in other genera they go regu-
larly increasing, until the wing is perfected in the Saw-
flies and Bees. It makes our microscope so much more
valuable when it helps us thus to a personal acquaintance
with the “ winged things ” around us — when the eye
becomes educated to discern the letters of creation’s alpha-
bet ; for we are but children in the ‘ First Reading-book/

Objects for the Microscope . 113

and I doubt not there are volumes, countless and full of
eternal wisdom, laid up in store for those who delight in
the study of God’s works.

We can now return to the slide before us. The colour
of the Saw-fly is necessarily lost in preparing it transpa-
rently for our examination ; but it was a bright and beau-
tiful fly, yellow, or scarlet, or light green dotted with black.
They provide for their young thus. 1 had the pleasure of
watching the motherly care of the Saw-fly of the rose (Ten-
tliredo rosce) last summer.

A busy little fly with black thorax and yellow abdomen
was at work upon a rose-tree so intently that she did not
stir when I drew near to see what she was about. She bent
her abdomen as you see here, and had protruded a pair of
cutters such as these. They are, in fact, finely-toothed saws
with about eighteen teeth each, and run backwards and
forwards in a grooved back-piece, which fits on each like a
carpenter’s tennon saw. They worked alternately, and pre-
sently she changed her position : she had been cutting down
deep, now she wanted to make a long groove, and straight-
ened her body, sawing quite fast and steadily, making a
furrow about half an inch long. Then she paused, and a
little greenish egg was laid on one side, another on the
opposite side, all along until a double row had been depo-
sited of about twenty eggs ; she then gave out a frothy glue
which seemed to fix and protect them, drew in her ovipositor,
and flew off to a neighbouring tree, where I took her for
examination of the saws. The little eggs I looked at with
a pocket lens, and found they were separated up the middle
of the groove by a fibre left on purpose. From day to day
I watched them, and they increased in size, which is differ-
ent from all other eggs ; the edges of the furrow became
black and swollen, but did not close, and about ten days
after I found all the little eggs empty, and several tiny green
and black-dotted caterpillars wandering about, very like
true caterpillars, which they are not, as may always be
known by counting their feet, eighteen or twenty, whereas
the larvae of butterflies and moths, which are real cater-
pillars, have only from ten to sixteen, and never more.

114

Objects for the Microscope.

Frequently our gooseberry trees are stripped bare by
hosts of these young Saw-flies in larvse ; they spin cocoons,
and remain coiled up in them all through the winter, re-
maining but a few days in the pupa state, and emerging in
May and June.

CYPHEUS PYGMyEUS,

another Saw-fly. It will be most interesting to the farmer,
because its larva is very troublesome in the wheat and rye-
fields, especially in France, where it often destroys a great
part of the crop. The fly itself is black and yellow ; the
male, as usual, differs from the female in colour and size ;
that is, he is of a brighter yellow, and the wings clearer
and more iridescent ; hers are clouded, and the yellow of
her body and legs more ochreous. The larva is singular in
having no legs at all, but a kind of tube at the end of its body
with a telescope movement by which it progresses along its
tunnel, for it feeds in the stem of wheat or rye ; and its
history is interesting. The female Saw-fly may be seen in
a warm April day sawing a hole just beneath a knot in the
tender stem of the young wheat, and depositing one egg in
each straw. This is soon hatched, and forthwith the larva
begins to gnaw, with some exceeding strong though tiny
mandibles, the juicy inside cells of the stem, which of course
disturbs the economy of the plant, and prevents the upward
flow of all the nourishment which is needful for the growing
ear. As soon as it can it proceeds to grind away the in-
terior of the knot also and ascend the stem. As it grows
and thrives, the plant withers ; but in the month of July
begins to descend toward the earth, and a few days before
harvest-time it settles itself near the root of the wheat, cuts
the straw regularly round inside, so that it breaks off under
the first puff of wind, and the little creature spins a warm
cocoon and lays itself up for the winter, fat and happy, un-
less a certain little cousin, one of the Ichneumon-flies, has
found it out, when his life will not have reached this period,
or its mischief have been so fatal

Objects for the Microscope.

115

ICHNEUMON-FLY.

( Pachymerus calcitrator.)

Always have several of these in your collection ; they are
beautiful and most interesting ; they have been appointed
to do a certain work, they have been gifted with wonderful
instinct, and provided with fit instruments to perform it,
and they are one of our many examples of obedience to the
order of God, which we would do well to pause and con-
sider. This little unheeded fly, — watch for it and learn its
habits ; examine it here as it is prepared for you.

It was black and reddish, with brown edging, and white
lines across the segments of the abdomen. This we cannot
see here ; but we can see the antennae, its first needful in-
strument for work, with twenty-two joints, each with a
bristle inside, the wings large, transparent, and iridescent,
the stigma yellowish-brown, the one marginal cell elongated.
(Compare it with the wing of Cypheus, which has two
marginal and four sub-marginal cells) and one sub-marginal
large cell, with a little nerve running into it. The thighs
are thick, and the tibiae spurred.

They abound often on IJmbelliferae.

And this is its use in the world : to find out the larvae
of Cypheus pygmceus , wherever it may be, and destroy it by
laying one of its own eggs inside its body, which, when
hatched, will feed upon the fat of the destroying insect,
and finally kill it, by preventing its further development.
Now, considering that the Saw-fly maggot is carefully con-
cealed in the wheat-stalk, the work is not so easy ; for the
stem must be pierced at precisely the spot where it lies, and
the Ichneumon must ascertain that no other fly has pre-
ceded her, or the life of her own offspring will fail.

The antennae ascertain this for her ; they vibrate inces-
santly as she runs rapidly up and down every stem, and
whether they hear the gnawing of the little maggot within,
or feel the consequent vibration, or smell the larva through
the pores of the stomata I cannot tell ; but it may be
that it by all these finds out the precise spot, and then with
its long ovipositor, which is barbed and works like an auger,

116

Objects for the Microscope .

a hole is pierced and the egg laid just where it ought to be.
The great and unaccountable marvel is, how it knows whe-
ther the larva has been touched before or not. But so it
is, and thus it avenges us of our tiny enemy.

MICROGASTER GLOMERATUS.

These you will always find mounted at Baker’s, Smith and
Beck’s, and Ladd’s. They are exquisite little creatures and
some of our best friends. Observe its large eyes, its beau-
tiful antennae, the last joint sculptured so delicately that it
can only be well seen with a J-inch lens. The ovipositor
is partly drawn out, and if the insect is well prepared, you
may see the mechanism by which it acts, — two powerful
elastic springs, braced across by three loops or tendons on
each side, which keep the instrument in place during its
rapid action. This fly is metallic green and gold ; the wings
have but two cubital cells, and, owing to their want of
nerves, can seldom be properly displayed. So they should
be examined on the unprepared insect, which is abundant
on our windows and in our gardens.

The first time I saw the transformation of this Ichneumon
was a great surprise, — a child’s wonder never forgotten.
I had kept some Cabbage Caterpillars in a box, feeding
them duly, and expecting the white butterflies whose pretty
eggs I had read of and longed to see ; when, one day as I
was considering my largest caterpillar, now full-grown and
ceasing to eat, instead of commencing as usual to prepare
itself for transformation, I saw in one moment that it was
dying, and a host of tiny worms suddenly pierced from its
inside in all directions, wriggled out, and began to spin
so fast that in about ten minutes nothing could I see but a
heap of small yellow silk cocoons, and the skin only of my
poor fat caterpillar. What it meant I could not tell, nor
had I then read the account of it in Kirby and Spence ;
but I took the cocoons, put them in a glass covered with
muslin, and in about a fortnight from that time the cocoons
were pierced and empty, and twenty of these pretty green
and gold flies were out. I learnt their name afterwards,

117

Objects for the Microscope .

and that they are onr appointed avengers to check the
depredations of the Cabbage Caterpillar, — the Microgaster
Glomeratus.

APHIDIUS AVENGE, — EPHEDRUS PLAGIATOR, — CEKAPHKON
CARPENTERII.

These Ichneumon-flies defend us in the same way from
the Aphides which disfigure our rose-trees. The first two
lay an egg in the body of the Aphis, which is inwardly
devoured by the larva and dies ; we may see it turned
brown and still adhering to the leaves. If the fly has
escaped, there will be a small round hole in the side of the
Aphis, and a little circular door attached by an uncut por-
tion of the skin. The Ceraphron, a most lovely little fly,
destroys, not the Aphis, but the larva of the Ephedrus
inside the Aphis. It is able to find out, even in an appa-
rently healthy Aphis, that an egg has been deposited by its
sister Ichneumon, and that the larva is hatched, when it
immediately pierces the already smitten insect, and provides
for its own offspring in laying its egg inside the internal
parasite. Thus, in preparing many of the brown and black
dead bodies of Aphides, we may obtain specimens of each
of these beautiful Ichneumons.

CHELYMOEPHA PHYLLOPHOEA, OR THE TURTLE-SHAPED
LEAF-BEARER.

This most curious insect is the pupa of Chelymorpha, an
insect discovered by the Rev. J. Thornton, on the leaves
of the Maple (Acer campestris) ; it is intermediate between
the Aphis and the Coccus. The singular leaf-like appen-
dages round the body and attached to the legs require a
half-inch object glass.

118

Objects for the Microscope.

CHAPTER IV.

DIPTERA.

** O happy living things ! no tongue
Your beauty may declare ;

A spring of love gushed from my heart,

And I blessed you unaware.”

Ancient Mariner .

Of all the insect tribes in that world which lies about us,
and of which we know so little, with all our learning and
research, there is none which has been more neglected than
the numerous and interesting one of the Diptera, or two-
winged flies. Most strange that it should be so ; for they
are the least harmful and the most truly beneficial to man of
any small creatures ; few of them assault us, and as a body
they are so important that the world could almost as easily
do without flowers or sunlight as without Flies !

They are beautiful. Who has not unconsciously paused
to admire the metallic lustre of an unknown Beris or Doli-
chopus, as it rested on the laurel-leaf by his side ; or the
golden Leptis sitting on the gray bark of some old tree ;
or the variegated Syrphus and the pretty Empis thronging
the umbelliferous plants by the wayside ? Who has not,
in the listless heat of a summer’s day, watched the merry
dance of the little House-fly, and wondered if there was
not more intelligence in that world of flies than he had
dreamed of? They are useful; for the Diptera in their
larval state feed upon the dung of animals and decaying
substances, and we should perish from the noxious vapours
or gases which arise from dead matter without these little
scavengers.

We are indeed in a world visible yet unknown, the
perfection and order of which no human eye had ever seen
without this help from Gfbd, whose directing providence

119

Objects for the Microscope .

gave man the microscope. His world it is ; His creatures
these, and of all the countless host of “ creeping things,”
the Diptera seem to come most nearly and constantly
within our reach. Other insects we must seek abroad in
woods and meadows and by the river-side, and only at
some seasons of the year do we meet with them ; but the
Diptera are ever within reach — our little home friends. The
invalid may sit all the year round within the shelter of his
room, yet seldom fail of finding a few of these to watch
and to admire. The little Phora lingers through the winter
on our window-panes, and the pretty Midge hops to and
fro in December days ; whilst with the earliest sun of
February the quiet heavy-looking Musca rudis appears in
numbers long before the active merry little Musca domestica ,
or House-fly, awakes from its long nap in some snug
unsuspected hiding-place.

Those who have not learnt to know and love the living
things around us, walk to and fro amidst many untasted
pleasures. I often think the difference between such igno-
rance and the knowledge we might easily attain resembles
that which we feel when walking alone and friendless in the
crowded streets of London with a stream of fellow-creatures
hurrying past, of whose life-history we know nothing, and
for whom we care nothing ; and the same walk taken in
our native village or island home, where every one we meet
is an acquaintance, relative, or friend, or friend’s friend,
striking unconsciously the electric chain of sympathy.
Even if we know but a name, it is something that is akin
to brotherhood. Thus also before we know the structure,
habits, and names of insects, what are they to us ? Every
wrorm is a worm ; a beetle is a beetle ; every fly is a fly-
nothing more.

But take the trouble to examine one little insect — the
humblest, the commonest — -learn how wonderfully it is
fashioned, how gifted with happy instincts, and how
obedient in its work — learn its name, and give it a kindly
look just once , and a little friend is gained for life ; you will
never again catch a sight of that small insect without a
feeling akin to brotherhood — you know it , and it may be

120 Objects for the Microscope.

association of place and time will enhance the pleasure
ten-fold.

There is not any small work that I know of on the
classification of the Diptera : the best manual of British
Flies is that of the ‘ Insecta Britannica,’ in three volumes-
too expensive and too scientific for popular use.* There-
fore these slides of whole-mounted Diptera, with the brief
descriptions of this catalogue, will be the more valuable, as
giving the young student his first introduction to a family
he will become better acquainted with hereafter.

Very briefly let me preface the examination of the first
slide with a list of the principal families into which natu-
ralists have divided the Diptera. As the Coleoptera are
known by the joints of their tarsi and structure of their
antennae, so the Diptera are classed according to the form
of the antennae and the veining of the wings.

There are two great groups, Nemocera and Brachyura.
The Nemocera comprises all the Tipulae, Gnats, Midges,
&c., which have long antennae, from six to ten-jointed, and
inserted in front of the head between two large compound
facetted eyes. The slides of head of Tipula and head of
Gnat will illustrate this better than any description, and
enable us at once to recognise one of the Nemocera. A
slide of a whole Gnat and of a Ptychoptera will give
a better lesson on their general structure, if carefully
examined, than any book.

CULEX PIPIENS.

The common Gnat, both male and female, should be
mounted, as the former only has the beautiful plumed
antennae, and the latter only the apparatus called the sting,
of the Gnat, and described under “ Head of Gnat.” Its
wing is often mounted as a separate object, to show the
scales, and has therefore been noticed with the wings of
other insects (page 89). But as this little fly is one of our
most common acquaintance, though not a very pleasant
one, a slight sketch of its habits will be interesting.

* Insecta Britannica : Diptera, by Walker. Histoire Naturelle des
Insectes : Dipteres, by Macauart.

Objects for the Microscope.

121

The female Gnat is that blood-thirsty little creature whose
shrill clarion sounds an attack upon man and beast
throughout the warm summer’s day and night. She flies
silently in the spring, and seldom thirsts for blood until she
begins laying eggs ; of these she produces about 300 in one
season in stagnant water, and their transformations occupy
about a month ; so there are several generations in one
year, which accounts for the swarms which occasionally
trouble us.

A few of the larvge of the Gnat are amusing in the
aquarium, and being, when young, very transparent, give
excellent observation of the circulation of blood and of the
tracheal organs.

The little Gnat lays her eggs in the form of a boat, which
floats upon our waterbutts or ponds for about a week, when
it sinks down to the bottom, and the young larva escapes
from each egg. This rises to the surface for air, which
it breathes through a most curious organ placed at the
extremity of its body, and it hangs, therefore, head down-
wards whilst breathing. This organ is a tube which
springs from the last segment but one of its abdomen, and
terminates in five points like a star. In the interior of
this tube a tracheal vessel runs which supplies the body
with air, and carries down a little bright globule when the
larva descends to the bottom of the water; this renders it
so buoyant that its greatest elfort is required to descend ,
and when the insect wishes to rise again, it has only to
unclose its tube, and it ascends without any exertion to
the surface, remains suspended there, drinking in the sur-
rounding element, and swallowing shoals of little “ living
things,” invisible except under the microscope. A tumbler
% of stagnant water will not only show the merry evolutions
of these larvse, but an abundant variety of the Infusoria,
upon which they feed, Monads, Paramecium, Rotifers,
together with the Desmidiacese, which abound in such
water.

In the next change the Gnat larva becomes a pupa, with
quite a different appearance and respiratory organ ; for now
it has two horn-like appendages on the upper side of the

8

122

Objects for the Microscope.

thorax, and it rises with its head upwards to breathe
through them. As soon as the last change is at hand, the
pupa raises its thorax out of the water entirely, and
slightly turns up its tail, floating like a boat ; presently
the skin bursts, and the head of the enclosed perfect
insect emerges, the long antennse wave to and fro, and the
frail bark rocks from side to sid 'em some peril, for the
lightest breath of air would overset it. Then one by one
the legs are drawn forth and stretched forward to some
floating leaf or stick whereby to steady itself ; slowly the
rest of the body follows ; the wings, hitherto pressed to
its side, crumpled and damp, are dried by the warm atmo-
sphere, and the quick breathing of the little Gnat sends a
rush of air through the delicate veins; they are gently
waved for a few seconds, then up and away flies the
rejoicing creature into its new and happy life.

Such is the history of the pretty microscopic object on
the slide before us.

Of its structure it is necessary to know that all the
Diptera are distinguished from other orders of insects by
having only two wings, and a pair of stout organs, called
halteres, which are supposed to represent the posterior
wings of the four-winged tribes, and respecting which ento-
mologists are much divided. They have been specially
noticed at page 142. The Diptera have mouths variously
constructed for their necessities. Their food is essentially
fluid; the juices of plants or of insect bodies, and of
decomposing matter, forming their nourishment ; and,
therefore, instead of the strong horny mandibles of a
Beetle, we find in such flies as Tabanus a pair of lancet-
like organs for plunging into the skin of the animal whose
blood it delights in, and beneath these another pair, to
which are attached large palpi, exactly corresponding to
the maxillse and maxillary palpi of the Coleoptera ; a
labium or lower lip, which in all flower-haunting and
honey-loving flies is very long and beautiful, as in Rhingia,
Syrphus, Oonops, and many of the Muscidse ; a labrum or
horny borer prolonged in the predaceous flies, and very
remarkable in the Empidse and Asilidse, which have also

Objects for the Microscrope .

123

a beautiful lower lip or labrum, used first for steadying the
lancets in their descent through the skin, and then for
sucking up the fluid. This may be watched by any one
who will permit this little Gnat quietly to take a meal on
the hand ; and once fixed she is not easily alarmed, but
will allow the approach of a pocket lens, and observation
of her proceedings.

The Diptera have also a tongue ( lingua ) ; it is not the
organ usually so called, but a lancet, which with four
others lie concealed within the horny lip or labrum of
Tabanus. The part we so much admire in the proboscis
of the Blow-fly, Tipulse, and others, is the lower lip or
labium, with its lobes striated by radiating tracheae.

The head of a fly is attached to the thorax by a very
slender neck, and appears to move upon a pivot, having
the power of turning quite round.

The thorax is compact, and gives support to the wings,
hal teres, and three pairs of legs.

The abdomen is composed of from five to nine segments,
and females are provided with ovipositors, sometimes of
great length, and consisting of a series of little tubes
sliding one into another like a telescope.

The legs have always five tarsi, two claws, and two or
three membranous lobes, or pulvilli. Of the internal ana-
tomy of flies I must not allow myself to say much ; but it
may interest many to know that they possess the dorsal
vessel or heart which ensures the circulation of blood, an
alimentary canal for the digestion of food, provided with
salivary vessels, biliary tubes, and a chyliflc stomach which
seems to supply the whole intestinal canal with a power of
digesting food when necessary. Flies have a crop or gizzard,
situated just above the stomach, and appended by a long,
narrow neck to the throat or oesophagus ; but it is used
chiefly as a reservoir for food, when the insect takes more
than is needful for its immediate wants. This was proved
by that great anatomist, Hunter, who kept a fly twelve
hours without food, and then gave it milk and killed it ; he
found no milk in the crop, but it had got through almost
the whole tract of intestines ; the animal had immediate

124

Objects for the Microscope.

occasion for food, and therefore the milk was not detained
in the crop, the intestines having the power of digesting it.
Another time Hunter allowed some flies to feed plentifully,
and then found the crop quite full, as well as the intestines.
Insects have no absorbents ; the chyle, which is a clear,
greenish fluid, with round oval corpuscles, is supposed to
transude through the coats of the intestine into the abdo-
men, where it meets with the blood in the ill-defined veins
that permeate the body. (See 1 Owen’s Lectures on Comp.
Anat.’) *

The tracheal vessels or breathing organs have been noticed
in the chapter on spiracles and tracheae.

The nervous system is similar to that of other insects,
consisting of two spinal cords or threads, exhibiting a series
of knots or ganglions. The Fly has one in the head, a very
large one in the thorax, and one, or sometimes two, in
the abdomen ; these give out nerve-branches to the wings,
halteres, and legs.

In looking at a slide of Culex observe the length of the
coxa, and the small joint called trochanter, between the coxa
and femur.

If possible, obtain the male of Culex annulata with its
magnificent antenna; and feathered palpi, and the female
of Culex pipie ns for the display of the suctorial mouth.

PTYCHOPTERA.

This is one of the family of Tipulrn, Crane-flies, or
Daddy-long-legs, which abound in the neighbourhood of
water, and are recognised by their black and yellow bodies
and spotted wings. The larva is an aquatic worm, and
the pupa has a curious, long, thread-like appendage,
through which it breathes. We find it in shallow water
at the brink of muddy ponds.

The wing is a good study after that of the Gnat, as
an example of wings without scales, and of the peculiar

* The stomach of the Fly, mounted in balsam, is an interesting object
and kept in most collections for sale.

Objects for the Microscope.

125

vein in g of the Nemocera. The costal vein is the one which
borders the fore-part of the wing, ending at the tip. The
next to that is the sub-costal , which here is prolonged to
five-sixths of the length of the wing, and connected with
the radial by a very short veinlet close to the tip ; the
radial and cubital spring from a common petiole, which
is about one-sixth of their length, and proceeds from the
sub-costal at half the length of the wing ; it is connected
writh the externo-medial by a transverse veinlet at a little
before its fork ; the cubital is forked at half its length ;
the externo-medial also forked. These two veins being
distinguished thus, help the eye in determining the others.
Observe also that faint streak or spurious vein between the
forked veins. This wing has no discal areolets, such as
are always found in the true Tipulae, or Daddy-long-legs.
These numerous parallel veins in a solitary wing would
enable us to ascertain the division to which the fly belonged,
even if the long antennae and peculiar palpi were unseen.
A collection of wings alone from this group would be
highly interesting for comparison, and for their beautiful
delicate forms.

The halteres also should be carefully mounted, and the
clusters of nerve-vesicles observed, especially those of Tipula
gigantea , T. Oleracea , Limnobia, and Bibio.

SCATOPHAGA.

This brings us to the second great group of the Diptera,
in which the common House-fly, the Blow-fly, the Horse-
fly, and others well known, are found.

THE FAMILY OF THE BRACHYCERA,

in which the antennae are short, never exceeding ten joints,
more frequently having only from three to six. The wings
also have branched veins, and are fewer in number than
those of the Nemocera. Their bodies are stouter, and the
palpi short, projecting above the proboscis, or lying on it.

These are the flies which throng our flowers, haunt the

126

Objects for the Microscope .

woods, the meadows, the leaves of trees, or act as scaven-
gers to remove the noxious substances in the field or by the
wayside.

There are twenty-eight families, each containing many
genera and species, which can only be learnt by long and
careful study, with the help of such works as 1 Walker’s
British Diptera’; but we can very easily become familiar
with those which are thus mounted, and, through them, with
others which flit as yet unheeded around us. Nor will it
be long, I hope, before some small manual of the Diptera is
published, more attainable to the young student than the
one already mentioned.

THE SCATOPHAGA,

(St er cor aria),

is the common Dung-fly, seen all the year round, but
especially in summer, resting upon cow-dung and deposit-
ing its eggs therein. It is also often on the window-
panes. The male has a round hairy abdomen, the female
a naked pointed one. They are yellowish or olive-green
flies, the head yellow between the eyes, and with black
drooping antennae ; thorax brownish above with four darker
stripes ; the wings are grayish, with a tawny tinge along
the veins.

This preparation is very valuable, as showing the
antennae well. We perceive the very different structure
from those of the Gnat or Tipula. There are only five
joints visible, although six are reckoned by naturalists.
The third joint (reckoning from the base) is twice as long
as the second, the fourth obsolete, fifth and sixth seated
upon the third like a bristle, and called the arista. The
head of Scatophaga is very bristly, as you see ; and so also
are the legs, which we may next observe. The eye and
tongue of a fly are fully described under the slide of Head of
Bhingia, or Syrphus. The joint of the leg nearest to the
body is the coxa, the next to that the femur, or thigh, then
the tibia, or shank, and then the tarsi, or small joints
in mediately above the foot. To see the foot well requires
a higher power, that the delicately fringed pul villus may be

127

Objects for the Microscope.

seen edged with glandular hairs, open at the point, and
secreting a glutinous substance, which enables the fly to
attach itself firmly to glass or ceiling, whilst those two
strong hooks are used to detach it from the surface to which
it clings.

The wing is next to be observed. It is the most im-
portant to the naturalist. Those small winglets at the base
are called the alulce ; they distinguish some families, and
generally cover and protect two small organs, the halteres,
supposed to be the seat of smell, described at page 142.
The wing itself consists of a double membrane, more or less
transparent, attached to nervures or veins, which are hollow
tubes containing spiral air-vessels, communicating with the
spiracles or lungs in the trunk. This construction is won-
derful for lightness and for strength ; the larger and heavier
the body is, the more of these strengthening veins the wing
has. And as by breathing only these vessels are filled with
air, or some subtle fluid, the very act of flying may be but
the palpitating of a joyous little heart. We know that the
tracheae are filled with air, and that the dorsal vessel is in
truth the heart, sending forth streams of the life-blood
throughout the body and into the wings, as may be distinctly
seen in the transparent veins of a newly-hatched fly.

But to learn the names of the nervures or veins of a fly, —
a most useful lesson, — no wing is better than this simple
one of the Dung-fly. That strong vein bordered with hairs
on the foreside is the costal vein ; it runs round the tip of
the wing, and ends where it meets the cubital vein. The
sub-costal is a pale short vein nearest to the fore-border,
and ending at one-third of its length.

The mediastinal is the next and a stouter vein, ending at
beyond half the length of the wing.

The radial forks at its base, and the farthest branch is
the cubital vein, joined to th q prcebracliial vein by a clouded
transverse vein.

The upper transverse vein, which unites the prcebracliial
to the pobrachial , is called the discal transverse.

The membrane itself is exquisitely dotted with fine hairs,
and fringed all round with longer ones.

128

Objects for the Microscope .

The Scatophagse feed on smaller Diptera, and deposit
their eggs in dung, and these eggs are so shaped that
whilst they are warmed and nourished in the soft excre-
ment, they cannot sink, two little horns on either side
supporting them in it, which enable the young larva safely
to escape.

LONCHOPTERA.

Small flies, very active and abundant in marshy woods
and grassy spots.

You can observe a difference here in the antennae ; the
roundness of the fifth joint and long arista ; the first three
joints are scarcely seen in this specimen. The wings will
give a good example of a simple veining, no transverse
vein at all, and the praebrachial forked ; each vein is fringed
with delicate hairs. This is a male fly, and has two hairy
lamellae at the base of the abdomen.

BIBEO.

(One of the Gnat Tribe.)

Look at the very different antennae projecting fiercely
forward, with nine joints ; the palpi on each side of the
tongue with five joints. The wings, how different from the
true Fly or Musca ! It has many veins, and thirteen areo-
lets, but so faint that we cannot see them all in this pre-
paration ; only the costal , sub-costal, and mediastinal being
distinctly marked. The legs are worthy of observation.

The fore-tibia, with a circle of spines at the joint; the
fore-femur, very stout, and the coxa and trochanter are dis-
tinctly seen in this specimen. The larva of Bibeo lives in
the earth, feeding on decayed vegetable matter; it has rows
of short hairs which it uses for locomotion, and twenty
spiracles for breathing. The pupa is found naked in an
oval cell with a very gibbous or horny thorax. There are
twelve species of Bibeo.

DOLICHOPUS.

A very curious fly, and one of our common garden friends,
in the neighbourhood of Oxford or anywhere near ponds
and rivers : for it is a water-loving insect, though we find
it on our window-panes, and basking in the hot sun at

Objects for the Microscope. 129

noonday on rose-trees and other shrubs. It is quickly
noticed from its long legs and metallic round-backed body,
carrying its head low, and sometimes found with another
fly in its mouth, being very predaceous.

There are fourteen genera of the Dolichopidse, each con-
taining many species ; and some parts of their internal
anatomy present peculiarities so great that much has been
written about them by Latreille, Harris, Dufour, and others.
Their habit is to run along the surface of still water like
the Velia rimdorum {see Velia), and they catch smaller flies,
aquatic worms, and even small gasteropods, the little Physa,
and smaller Planorbis ; there is a gaping orifice at the end
of the proboscis, which admits and holds the prey until the
juices are sucked out.

We know not where they lay their eggs, but the larvae
are found as white slender worms of twelve segments in
May, underground in damp earth, and in June they change
to pupae, casting their skin. The head of the pupa is armed
with several points, the ends of the legs in their sheaths,
somewhat detached from the body, and a process resembling
an S is on each side of the thorax, probably for respiration.
The Dolichopus emerges from the pupa in about three
weeks’ time. Now let us examine the slide.

The head is broad ; the eyes large, and in life were very
brilliant. The antennae stand fiercely out and require
examination with the J-inch ; they are quite unlike any we
have yet seen. Observe three distinct joints besides the
arista or spine, which points forward ; the second joint,
the shortest, fringed with spines and intromitting a slender
tube obliquely into the base of the third ; you can see a
kind of loop or dark spot where it is inserted ; the third is
so remarkable that whenever you see this compressed and
peculiar shape you need not doubt that you have a Doli-
chopus. The arista is two-jointed, and in some species it
is ciliated.

The proboscis is short, directed downwards ; the head
itself is armed with long bristles. The abdomen has five
segments, and on each of them you see a double row of
white spots, which are the spiracles; the end of the

130

Objects for the Microscope.

abdomen bends suddenly inwards, and these last two
segments are called the hypopygium, which has an outer
pair of appendages like fringed plates ; they seem to be
concave and join together to protect a number of internal
organs of varied shape which we see projecting beneath,
and the use of which has been largely considered by
Dufour. (‘ Annales des Sciences Naturelles/ 3me serie,
tome i.)

The wings furnish us with a good lesson, and an easy
one, for becoming familiar with the nerves or veins.

The costal-vein is fringed and strong, ending where the
prsebrachial meets it.

The sub-costal is very short and stout.

The radial and cubital spring together from a dot at the
base of the wing, and the prcebrachial, after passing the
transverse vein, make a slight curve toward the cubital.
Now, that very slight curve is of the utmost importance,
both as to position and shape ; it serves to assure you of
this being a true Dolichopus ; it is never wanting in the
species — never altered — no, not even by a microscopic line.
But in one of the same family, a cousin, called Psilopus,
there will be a little branch at the angle of the curve, and
in another relation, Dolichopus diadema, the curve is rec-
tangular, with a little branch. This Fly is common on
pools overgrown with plants.

So is Dolichopus nobilitatus , which is a gilded green fly,
easily known by its white-tipped wings, and when examined
with a lens you will observe that the arista is long and
very hairy ; the wing very narrow, and sloping away
without any lobe, or even angle, the anterior lines being
waved within the dark patch.

No Dolichopus ever has an axillary lobe to the wing.

That vein beyond the probracliial is the pobrachial ; but
the base of the wing offers the particular marks of the
group, and ought to be examined in a separated wing. I
dwell upon this, because the careful study of one wing is a
most valuable lesson : the eye learns what to look for ; it
learns accuracy of observation ; it learns what it never
forgets — the vast importance of little things ; and what

Objects for the Microscope.

181

the eye sees often the heart feels. Find out, therefore, a
very short and oblique vein, between the cubital and the
prcebrachial , down close to the dot of the radial , and the
space thus bounded at the base is called the prcebrachial
areolet, and its minute size and position in every one of the
genera is decisive of the family.

Pass on now to the legs, and remark the spines on the
femora and metatarsus; they will also serve to show the
species, for in some Dolichopus there is invariably but
one spine, in others four or two, and in some there is a
double row.

THE OPOMYZA

is one of a family group called Geomizides ; they frequent
recent or decaying vegetable substances, also our windows,
and are very present little unknown friends. We may
know these by their spotted wings, by the tawny body,
yellow head, thorax striped with three pale lines ; the
abdomen has a dark dorsal stripe or dark bands ; they
abound in herbage. Now examine the head and wings.

The head is broad and eyes large ; the antennae, like
those of a true Musca, three joints drooping, the third
round and large ; the arista long, slender, hairy, and with
a .small joint you will hardly see unless the head is in
profile.

The thorax is bristly ; the abdomen has seven segments
— a little hairy ; and then pause to look at the wings, and
compare them with those of Dolichopus.

You will first observe two transverse veins slightly
clouded ; the prcebrachial straight ; the discal transverse
hindermost, and joining the pobrachial vein to the prce-
brachial ; the cubital and radial veins are quite straight.

CHLOIIOPS.

A mischievous little Fly ; and the farmer will be inte-
rested in seeing the parent of that larvae which sometimes
commit such havoc in his wheat-field. In England there is
a disease known as the gout, from the swelling it occasions

1 32

Objects for the Microscope.

in the stems of wheat and barley, but which is called the
frit in Sweden, where it occasions enormous loss — as much
as one hundred thousand pounds sterling annually. This is
caused by the little innocent-looking Chlorops on the slide.
It effects this by simply depositing its eggs early in June on
the stem of the young wheat, which being as yet low in the
sheaf, the little maggot hatches and feeds in the shelter of
a leaf, mines into the stem, but does not enter the hollow
part. It is well that it does not do so ; for we know that if
the cells of a plant are destroyed in the channel of its life,
which is the stem, of course it presently withers, or brings
forth but imperfect fruit.

More harm would this insect do if its propagation was
not checked by a good little Ichneumon -fly ( Ccelinius )
which is commissioned to destroy its larvae by laying itsown
egg inside the maggot of Chlorops, just as the Microgaster
does in the caterpillar of the Cabbage Butterfly, and thus
defends us from our tiny foe.

These Chlorops frequent our windows, often in swarms —
known by their large green eyes ; their yellow and black
bodies and beautiful wings lying along the body and ex-
tending beyond it. You can rarely mistake it ; and then if
you have this mounted specimen you will observe its pecu-
liar antennae, the third joint knobbed, the arista seated side-
ways upon it, and like a fine long bristle. The thorax
striped ; three broad stripes and one slender line on each :
outside of these a black dot on the side of the breast. The
scutellum was yellow ; the abdomen short, broad, with dark
bands, and itself pale greenish-black.

Observe, in the wings, how the sub-costal and medias-
tinal are joined in one strong vein, which meets the costal at
nearly half its length ; the cubital ending at the tip of the
costal ; the radial ending at three-fourths of its length ; the
prccbrachial ending on the hind border, near the tip ; the
pobrachial ending at beyond half the length. There are two
transverse veins.

This slide will help us to recognise both our enemy,
Chlorops teniopce , and our little window-friend, Chlorops
lineata. The abdomen of the latter has a yellow tip and

Objects for the Microscope. 133

base, also three black spots on the pectus, or fore part of
the thorax.

PHORA.

All the year round the little Phora is upon our windows
and in our stables, when no other flies are to be seen, but
perhaps some eccentric little Midges, hopping diagonally
here and there — scarcely a living thing to study ; yet we
shall always find a Phora running restlessly but happily to
and fro, with a bent body and depressed head ; the antennae
very short, but with a long slender arista carried back-
wards, the third joint quite round, the first and second very
small.

The wing has no traverse veins at all ; it is of the sim-
plest form, strengthened at the base by the stout costal vein ,
which ends however before half the length of the wing, and
is ciliated ; the mediastinal vein, also stout, ends at two-
thirds the length of the costal ; the cubital vein and radial
vein in one, and forked at the end of the costal , all the
other veins represented by four veinlets, often indistinct.
Now compare this with the Leptis wing.

LEPTIS.

( Tringaria .)

A splendid preparation of a fly that is easily found and
captured by any rambler in woods, because it has a quiet
habit of sitting upon trunks of trees with its head down-
wards, and will allow a wine-glass to be capped over it with-
out any alarm. It may be useful to mention here that most
flies may be caught by a small tumbler, or stemless wine-
glass, and a handkerchief, or piece of card-board. I prefer
the handkerchief. The Leptis may thus be recognised : it is
a large fly with long pointed abdomen, tawny coloured, and
having three rows of black spots. The wings are spotted.
The thorax is that part which supports the wings and legs,
and in the Leptis it has three fawn-coloured stripes. The
legs are tawny and clothed with short black hairs.

This fly appears in the early part of the summer, and
haunts meadows and hedges as well as woods. It feeds on

134

Objects for the Microscope.

smaller insects, having a stout short labrum and slender sharp
maxillse, with which to kill, as well as a thick broad labium
(called the tongue), to suck the food. The larva lives in the
earth, in sand or manure, or decayed wood. The pupa is
brown, bare, with eleven segments, of which the five poste-
rior are furnished with a series of little teeth.

As it is quite impossible to prepare insects so as equally
to display all parts, we may find some difference in the
slides, even of the same insect. The Leptis I am now look-
ing at shows the beautiful eye and tongue, but not the
antennse, and yet they are to be observed as indicative of its
individuality, for the veining of the wing is, at first sight,
so like that of another family (the Stratiomidse) that we
might mistake it if we did not read its name in the antennse.
They are small, and seated side by side in the middle of the
face, four -jointed, the first short and cylindrical, second
transverse, third cyathiform, or cup-shaped, and a long fine
bristle makes the fourth joint.

Here we cannot but admire the delicate network of its
compound eye : in life it was of a bright green, and the
facets numerous and small. The labium, or under-lip, fur-
rowed in the centre, and beautifully marked with tracheal
vessels, acts also in contracting and dilating the tongue in
the act of drinking. The palpi, or feelers and tasters, are
remarkably large and hairy, projecting on each side of the
tongue.

The wings are to be the chief lesson ; comparing them
with the simply veined wings of the Phora, as an indication
of farthest remove in relationship, whilst they also show us
that the Leptis is a near cousin to the Tabanus, or Horse-
fly, and to all flies whose wing-veins are crowded together
near the fore-border ; the costal vein ending at the tip of the
wing, the cubital vein deeply forked, and the fore-branch
having a small areolet. There is a discal areolet, large, and
emitting three veins to the border, and the anal areolet is
open. Eight families, comprising many genera and nume-
rous species, have wings upon this plan, and are known by
the variation in the joints of their antennse. (See head of
Tabanus and slide of Pachygaster and of Beris.)

Objects for the Microscope.

135

No better example can we have of the leg and foot of
the fly than this slide presents ; for we see very distinctly
the coxa, or hip-joint ; the trochanter , a small joint by
which the thigh or femur fits into the coxa ; the tibia,
or shank-joint, which here is armed with two spines, and
the tarsi, or ankle-bones, as some think analogous to our
instep-bones, having two daws and pulvilli, or cushions,
set with glandular hairs. (See foot of fly in Scatophaga.)
Here observe the Leptis has three instead of two lobes.

ASILUS.

These are the most powerful and ferocious of the
Diptera, destroying Beetles and Ichneumon-flies, and may
be seen on the sunny side of woods, silently darting about,
or resting with a huge meal in their mouth, and then they
are pretty easily caught. They are bright, tawny-coloured
flies, very hairy ; the antennae erect and long, curved
upwards, and the proboscis standing forward.

This is an example of relationship with Leptis as to the
wing-veins, and yet with a difference. You see the cubital
vein is forked, but simply so ; the discal areolet gives out
but two veinlets, and is joined to the cubital by a short
transverse vein. The foot also observe — two deep lobes
with a spine between them. Then look carefully at the
antennae, and compare them with those of Leptis; you see
they are slender and styliform, and indicate an approach to
the tribe of Empis-flies, which, as they abound in our
gardens and may easily be procured, should have a place
in our object-box.

EMPTS.

(Snipe-fly.)

Either the black Empis livida we see so often on our
laurels or flowers in the months of May or June ; or the
Empis stercorea, which swarms on the umbelliferous plants
by the wayside ; or the pretty little Hilara that plays over
the water-meadows or great ponds : — any of these will give
a remarkable proboscis and a very pretty wing.

136

Objects for the Microscope .

EMPIS STEECOKEA.

A small, shining, yellowish fly, clothed with a few black
hairs or bristles ; the thorax with a black linear stripe ;
abdomen with three black stripes ; legs long, slender, and
yellow ; tarsi of a darker hue. The Empidse are a large
and very distinct family, containing twenty-three genera,
and are inhabitants of woods, hedges, fields, and gardens,
where they find their prey — smaller Diptera, and all kinds
of lesser insects. They are fierce and voracious, transfixing
their prey with their long proboscis, and sucking out the
juices with their beautiful up-curved tongue. The eyes of
a male Empis touch one another ; those of the female are
parted by a narrow front, a distinguishing mark of the
sexes in most flies. The antennae of the Empis always
stand forward, and observe how different they are from
those of either Dolichopus or Scatophaga. It is only by
thus comparing one slide with another that we learn our
lesson icell.

The antennae are five-jointed, close to each other at the
base, porrect, that is, standing out ; the first and second
joints bristly : first cylindrical ; second cyathiform, or cup-
shaped, about half the length of the first ; third, subulate
compressed ; the fourth very minute ; the fifth like a style,
pointed sharply. The thorax has a broad, black stripe ;
abdomen three black stripes, and every segment is punc-
tured with a double row of light dots. The legs are long ;
the coxa shorter than the femur , the trochanter very
distinct ; the third joint of the leg, femur , or humerus , is
usually the largest and most conspicuous ; generally
speaking, the anterior pair are shorter and smaller than
the posterior pair. If the insect leaps, the thighs of the
hind-legs are very much thickened for the development
and action of its muscles. This is particularly seen in the
legs of the small beetle called Turnip-flea (Haltica), in the
flies Ascia podagrica, one of the Syrphidse, and also in
Syritta pipiens, which should be mounted as examples of
the thickened and toothed femur, and of a curved tibia
joint. The Ascia is very common in the month of June,

137

Objects for the Microscope.

hovering over the long grass, and may be recognised by
its black and yellow body, and peculiar darting to and fro
from flower to flower. The fore-tarsi are often dilated in
the male Empidae, but those of E. stercorea are not so.

The Wing. — The wing of Empis stercorea will give an
excellent example of the veining peculiar to the family.
They are distinguished by these three variations : —

1. — The costal vein vanishes suddenly at the tip of the

wing, just where it meets the cubital vein.

2. — The cubital vein is forked.

3. — The discoidal areolet emits three veins to the interior

border.

The wings of Leptis and of Asilus have also a forked
cubital yo in, and three branches from the discal areolet ;
but they have other veins crowded together, which are
wanting in the Empis wing, and as the antennae are quite
as important to the entomologist in determining a genus
as the veining of the wing, by comparing those of a Leptis
with those of the Empis, a striking illustration will be
obtained of the progressive order and variety of likeness,
and yet of distinct difference, between the families,

iilLA'AA.

By the wing and the antennae we recognise one of the
Empis-flies, but a variation in the form of the third joint
and the shortness of the first two joints is the first remove
from the true Empis. Observe also the stout, short pro-
boscis, and if it is a male Hilara the fore meta-tarsi are
much dilated, forming quite a disc on that part of the leg.

How beautifully the wing is ciliated, the cubital vein
forked, the discoidal areolet emitting three veins, and a spot
upon the costal vein called the stigma, which in this wing
is marked by a broad brown shade.

These Hilarae feed upon smaller insects, and also on the
nectar of flowers. They assemble in swarms, and dance
together over a rivulet or river, on fine, warm summer
evenings. We have often seen them rejoicing in merry
play, rising and falling in graceful evolutions, sometimes
by one common impulse sweeping off down the stream, as

9

138

Objects for the Microscope .

if a breeze had suddenly wafted them away, or invisible
beings had chased them ; then slowly and prettily they
re-flitted back again to commence their gambols.

SYRPHUS PYRASTRI.

Many of the Syrphidae are mounted whole ; they offer a
great variety in the structure of the antennae, the mouth
and the legs. Some are so large that the head only is
mounted, to show the beautiful eyes and labium, as Rhingia,
Helophilus, Eristalis, &c.

They are our prettiest and commonest flies ; honey-loving,
flower-haunting, harmless little creatures. Most of them
are striped or banded black and yellow, and love to hover
in the air, over one spot, their wings almost invisible with
rapid vibration, accompanied by a shrill hum ; if alarmed,
they dart away with astonishing velocity, and are somewhat
difficult to catch. The family contains thirty-one genera ;
some of them so unlike the others as to require microscopic
observation and comparison ; the Eristalis, for instance, is
often mistaken for a Bee ; the Helophilus also, and Rhingia,
— the two former abound in the autumn on the Michaelmas
Daisy, and the latter frequents the woods and hedges, dart-
ing like a Wild Bee into the flower-bells, with a long pro-
boscis, looking to the unassisted eye like a Bee’s tongue.

The two distinguishing characters of this large family
are these : — the coalescence of the palpi with the maxillae,
and the spurious veins of the wing, one before th e prcebrachial
the other behind the pobrachial. The wing alone will
decide a Syrphus for a young entomologist ; therefore, in
examining this slide, let the chief attention be given to its
veining, also collect a few varieties, comparing the wing of
the common Helophilus with this one of Syrphus pyrastri ,
the type of the family.

The costal vein ends at the tip of the wing, where it
receives the cubital.

Mediastinal vein distinct, ending about the middle of the
costa.

Sub-costal , continued nearer to the tip, and ending
separately in the margin.

139

Objects for the Microscope.

Prcebracliial vein connected with the cubital by a trans-
verse vein near the margin, and between the two is a faint
streak or spurious vein crossing a second transverse vein
nearer the base.

The mediastinal areolet is coloured in this wing, and
appears like a narrow stigma between the sub-costal and
mediastinal veins.

Areolets are enclosures formed by the branching and
crossing veins ; they are important in the wings of the
Syrphidse, and must be observed.

All the Syrphidse have alulae, which are membranous scales
at the base of the wings, protecting and sometimes quite
covering the halteres. They are particularly beautiful in
Rhmyia and Eristalis , and deserve to be mounted separately.

In the wing of Helophilus the cubital vein curves sud-
denly inwards, forming a loop in the centre of the areolet.

The feet of Syrphus are beautiful, and from the trans-
parency of the preparation we see the articulation of the
tarsal joints distinctly, the spine at each tarsus, and the
strong hooks and delicate pulvillus of the foot.

Some of the Syrphidse have their abdomen nearly filled
with air, and partly diaphanous or transparent, when by
careful management the circulation of their blood may be
seen, and the pulsations of the dorsal vessel or heart may
be counted. Place the fly in a live box with just sufficient
pressure to keep it still, and between the segments the
fluid may be seen. The following extract from ‘ Walker’s
British Diptera7 (vol. i. page 285) will be interesting to the
student : —

“ The dorsal vessel of this fly (> S . pyrastri), instead of the
usual form which it had in the larvse, assumes the shape of
a flask, having its long end directed towards the thorax ;
the pulsation and transmission of the fluid in it is manifest.
This vessel extends in length from the junction of the trunk
with the abdomen to about the termination of the second
segment. The included fluid is propelled at intervals by
drops, first from the wide end towards the trunk, and then
in the contrary direction. It is conjectured that the neck
of this vessel is composed of two or more approximated

140

Objects for the Microscope.

tubes, and that the blood is conveyed forward by the out-
ward ones, and backward by the intermediate one ; also
that there is a secondary heart, at the extremity next the
thorax, for the purpose of causing the reflux.”

BORBORUS EQUINUS.

These are very abundant everywhere m rank grass, and
near decaying vegetable matter, upon which the larvae feed.
They are small black flies, remarkable for their thick fleshy
labium, and a broad bellying sheath below, which should
be seen in profile. Antennae rather distant, short, and tur
outwards with a long slender arista ; the first joint so small
as to be scarcely perceptible, the second nearly as large
as the third, which is obliquely compressed and ciliated.
The legs are long, and fore-femora thickened ; there is a
curious spine at the end of the hind tibia , and the tarsi
are short and broad. The wing, being very simply veined,
is an easy study ; the chief mark of this family being in
two small areolets near the base of the wing, close to the
hind border, which are called anal areolets , and in this
wing they are complete. The discal transverse vein is also
near the border ; it joins the prcebrachial and pobrachial
together, the latter does not continue beyond it. The radial
and cubital are branches from one common vein at the base.

There is a full account of this species and its larvae in
the ‘ Entomological Magazine ’ (vol. iii. p. 323).

SEPEDON.

A most beautiful specimen for the shape of the antennae
and the structure of the tongue. The wing closely resem-
bles that of Borborus, — the same transverse veins and anal
areolets ; but the antennae separate the genera entirely.
Instead of the short second joint in Borborus, that of
Sepedon is very long and spiny, with a conical and convex
third joint, from which springs the three-jointed arista.

The labium is set round with double hooks and curiously
dotted, — a most interesting variety in the proboscis of flies.

The legs are rather long, hind femora thickened, and
armed with a double row of spines.

Objects for the Microscope.

141

These flies are found amongst water-plants ; they are
black, shining, slightly metallic, with bright red legs ; the
halteres, also red, with a whitish band. Thorax with four
black stripes ; wings gray, with a lurid tinge in front.

SEPSIS.

The pretty little fly which we find upon our laurels,
walking about with raised and quivering wings. The larvae
feed on decaying matter.

The antennae are drooping and short, with the third joint
oval and larger than the first or second ; the arista bare.

Proboscis broad and large ; the wings simply veined,
but very delicate and beautiful, and with a black spot at
the tip, without alulae. The legs are remarkable for the
large spines in the fore-femora of the male, and for the
spiny meta-tarsi.

In all flies, as a rule, the fewer the veins the smaller the
body, and the more sluggish the flight ; the comparison
between the veins of Leptis, Tabanus, and Phora, or
Sepsis, will prove this.

The Sepsis wing has a costal vein running quite round
the tip of the wing, and ending on the hind border ; sub-
costal ending before one-third of the length ; mediastinal
ending before half the length ; radial ending near the tip
of the wing ; cubital ending quite at the tip. There are
two transverse veins.

This list of the Diptera, though by no means complete,
is sufficient to show how very instructive and interesting
these preparations are, and to encourage the young ento-
mologist to mount insects in this way for himself. The
method is easy, but requires patience and experience.

Soak the insects in liquor potassi for a longer or shorter
period, impossible to fix, because it varies necessarily with
the size and texture of the insect. A beetle may require
months, a fly but a few weeks or days, to render it trans-
parent, by dissolving its inward parts, and giving flexi-
bility to its integument. It is then washed in cold water,
and laid out upon a glass slide in the desired position.
When perfectly dry it should be soaked in oil of turpentine,

142

Objects for the Microscope.

which may be applied with a camel-hair pencil, and after-
wards mounted in balsam. In this last and most difficult
part let the balsam be very fluid, and the warmth gentle,
that the air may be quietly dispersed, and the bubbles
removed before the final covering with thin glass.

I recommend the Borborus and Empis stercorea as the
easiest specimens to begin with. When caught, if immersed
in hollands or spirits of wine, they will keep any length of
time until wanted for mounting.

THE HALTERES, OR POISERS, OF DIPTERA.

These small organs, which are very apparent as little
knobs on a stalk, like drumsticks, just behind the wings of
Blow-flies and the Tipulse (especially the Tipula olacea ,
which flutter against our window-panes), are rudimentary
wings. We only find them in the Diptera, which all
possess these much-disputed organs.

They are called poisers, or balances, because it was
formerly supposed that the insect used them as the rope-
dancer does his pole, to steady itself in the air. Some
naturalists fancied that they produced the humming noise
in flight by beating against two little scales at the base of
the wing, called alulae ; but* that can hardly be the case,
seeing how many insects buzz who have no halteres, such
as Bees, Cockchafers, Dung-beetles, &c., and that so many
flies who do possess them fly silently. They certainly do
move very rapidly, quivering as the insect flies, and even
when at rest I have seen the vibration. They are placed
immediately on the margin of the great thoracic spiracle,
and the late discoveries of certain organs inside these
halteres lead us to suppose they are organs of smell, as the
antennae may be of hearing.

HALTERES OF BLOW- FLY.

These, if mounted carefully in balsam, have become
transparent ; we see that they consist of three parts, the
base, shaft, and head. The organs in question are at the
base, two distinct groups of vesicles, which look like dots

Objects for the Microscope.

143

arranged in rows. The upper group is in spiral lines, the
lower is on a broad flat surface, and only on one side.
Each vesicle is a small sac, filled with fluid, and over-
arched by a protecting hair, and when a good side view is
obtained they are seen to be quite spherical.

The two naturalists, Dr. Hicks and Mr. Purkiss, who
have noticed these organs, suppose them to be olfactory
vesicles. There is a very large nerve given off from the
great thoracic ganglion into the halteres, larger even than
those branches which pass into the wings and legs of flies,
which makes it very likely that in these very small appen-
dages lies a great sensitiveness of some kind. No less than
360 of these vesicles are found in the halteres of Rhingia ;
and for what purpose ?

Dr. Hicks justly remarks, that it is scarcely for hearing ,
as they are so near the buzz of the wings, and them-
selves in constant motion, so that other sounds would be
drowned ; but that the current of air produced by this very
fluttering, and also the position of the halteres near the
largest thoracic spiracle, make it extremely probable that
they receive the floating odours in the air, and communicate
them to the brain, or cephalic ganglion, directing thus the
Blow-fly to the carrion, the Rhingia to the flowers.

HALTERES OF TABANUS.

“ These are very similar to those of the Rhingia, with
the addition of seven vesicles on the shaft of the halteres
to the upper part of the facet of the ridge, and another
group of eight or nine beneath the ridge opposite the
boarder facet.”*

The shaft of the halteres is tubular, and is the channel
for the branch of the nerve which passes up and expands
in the head.

The head of the halteres contains cellular substance ;
there is also a groove on one side lined with a very delicate
membrane, and beneath which there is a group of hairs.

* See ‘ Journal of the Proceedings of the Linnsean Society of London,*
November, 1856.

144

Objects for the Microscope .

CHAPTER V.

PARASITES.

A great many objects are sold for those who are curious
in learning the forms of those “living creatures” which
are nourished on the bodies of higher animals.

Every animal, from man downwards, is a pasture land
for many fellow-creatures. So surely we may call them,
formed as they are by the Almighty hand which fashioned
our own wonderful body.

However repugnant it may be to our refined tastes to
examine a flea or a louse, this arises from no inherent
ugliness of these creatures, but rather from our association
with them in scenes of dirt and misery, of personal discom-
fort also. Very probably they are the avengers of our evil
habits, the consequences of our fallen state, and yet merci-
fully ordered to do us good rather than harm, by com-
pelling the careless and the poor to that watchfulness and
cleanliness which might otherwise be neglected.

THE FLEA,

man’s great annoyance, is nevertheless a beautifully-formed
creature.

It has to be prepared by long soaking in turpentine, and
mounted in balsam, before we can see its various parts.

The flea belongs to the order of the Suctoridae. The
head bears antennae four-jointed ; eyes small, round, and
simple ; the proboscis is composed of two long mandibles
with serrated edges; two long narrow plates with fine teeth
and longitudinal ribs, these are the lancets ; two leaf-like
plates, nearly triangular, which are the maxillae ; two labial
palpi, two maxillary palpi, one slender suctorial organ

Objects for the Microscope.

145

called labrum. The thorax is composed of three segments,
and the abdomen of seven segments ; the female has nine ;
and both sexes on the last segment have that beautiful
breathing apparatus called

THE PYGIDIUM OF A FLEA.

This must be mounted separately to be seen well, and
it forms an excellent test object. Topping mounts it
beautifully.

There are twenty-five disc-like areolae ; in the centre of
each of these is a long hair, and round them a ring of
rectangular rays. It must be seen rather than described.

The legs of the Flea are long and many-jointed, the
hind pair having thick muscular thighs, formed for extra-
ordinary leaps, and terminated by five tarsi, and two curved
and toothed claws. Every part is worthy of observation.

The coxa , or first joint, is very thick ; the trochanter is
very small, the femur long and thick, the tibiae hairy.

There are many species of fleas, each of them parasitic,
on various animals, with some difference in structure. The
most curious are the

Pulex talpce, or Mole-flea, with its rows of spines on the
neck.

Pulex Gallince, or Fowl’s flea, which does not leap, but
runs swiftly, and has a most tormenting bite, driving hens
from their nests, and compelling their masters to keep the
hen-house clean.

Pulex Columbce , or Pigeon’s flea, very curious. The
antennae should be particularly noticed; the male carries his
erect, and the female has hers partly concealed in a furrow
near her eyes. The form is beautiful, — eight cup-like joints
set one within another, and surrounded by a circle of stout
bristles.

Pulex vespertilionis , or Bat’s flea, has a row of dark
spines just over its proboscis, called its cephalic setae, and
a collar of spines, called its proto-thoracic setae.

Pulex felis, the Cat’s flea, which has a prettily spotted
head, and in which we can see the spiracles on every
segment of the abdomen, and also the pygidium, is one of

146

Objects for the Microscope.

the best to mount for observation. The dots on the head,
and the femora being without hairs, distinguish it from the
human Flea.

The eggs of fleas are white, long, and viscid or sticky ;
the larvae vermiform, with thirteen segments ; the pupa is
enclosed in a silken cocoon.

PEDICULUS, OK LOUSE,

a genus of anoplurous insects.

Man is infested by three kinds of Louse ; but the com-
mon head louse is the one usually mounted for observation.
It has a flat and nearly transparent body, three pairs of
legs, terminated by a claw or hook, and a head which has
two simple eyes, and a long sucker concealed in a little
fleshy tubercle or snout. They multiply prodigiously, two
females producing no less than 10,000 eggs in eight weeks.
Leuwenhoek described them minutely, and seems to have
watched their manner of feeding and propagating with
great interest. Certainly their eggs are curiously formed,
with a little moveable lid on a hinge, which opens for the
escape of the young larvae, and the egg of the Pheasant-
louse is beautifully striated and dotted, giving it the ap-
pearance of worked net. Some parts of the internal
organization of a Louse are well worthy of attention and
dissection ; being naturally transparent, a little soaking in
oil of turpentine will dissolve the fat and render many of
the organs apparent.

The nerves of a Louse are remarkable, as forming a thick
spinal cord without breaks or intervals, after the ganglia of
the head, and from the end of which several rays or nerves
are given out to lower parts of the body, a slight constric-
tion only marking the united ganglia. These are visible
when the insect is properly prepared. The ovaries also are in
ten branches of bead-like threads. All the internal apparatus
is as perfect as in more beautiful insects, so little reason
is there for shrinking from or thinking meanly of even a
loathsome louse.

Objects for the Microscope.

147

Birds have many varieties.

The Pheasant-louse ;

The Parasite of the Rook and Chaffinch, called Ricinus
pavonis, are interesting objects.

THE ACARI, OK TICKS, MITES.

These parasites are found on animals, birds, and insects.
They belong to the lowest order of Arachnida, the Spider
tribe, and many of them are beautiful microscopic objects.

The Acarus scabici, or itch insect, is a very valuable pre-
paration. It is the occasion of that disgusting disease the
Itch, and is exceedingly difficult to obtain. It lodges in a
burrow near the pustule ; but, being scarcely visible to the
naked eye, is rarely extracted in a perfect state. When
examined under the microscope it is found to have an oval
body, a mouth of conical form, and eight feet terminated by
bristles. The head has five strong mandibles, with which
it cuts out a little nest under the skin ; it lays many eggs,
and is most difficult to eradicate.

ACARUS DOMESTICUS, OR COMMON CHEESE-MITES.

The dust of decayed cheese is composed entirely of these
mites, — their eggs and their excrement. Mounted properly,
we should see their oval body, with a head from which
extends two large mandibles, somewhat resembling the
claws of a lobster. When the insect is in repose it crosses
these mandibles over its head, forming a kind of roof over
the mouth. The legs are reddish, and inserted in two
different groups, the anterior pair considerably larger in
the male.

These Acari are both viviparous and oviparous.

ACARUS PASSULARUM,

found abundantly in dried figs, is like the cheese-mite, but
has very long bristles at the sides of the mouth.

148

Objects for the Microscope.

ACARUS PASSERINUS.

Found on all young birds.

IXODES, OR DOG-TICK,

a curious parasite, which has no perceptible eyes. It has
a toothed beak, which it fixes in the skin of the dog and of
the hedgehog, and it holds so tightly that it can scarcely
be detached alive. It deposits a prodigious number of
eggs, and are so voracious as to cause the death of some
animals from exhaustion.

MELOPHAGUS.

( Sheep-tick .)

This parasite belongs to the Diptera, though it is wing-
less. They abound on sheep, are easily taken and prepared.
Let them soak in potash for at least a month, then press
them and wash them well ; when dry, soak in turpentine
before mounting in balsam, and their structure will be
well seen. They are very brilliant objects when viewed
with polarized light.

The Melophagus is one of the family Hippoboscidce, of
which there are six genera, all of them parasites of mam-
malia and birds, feeding on the substance at the roots of
the hairs and feathers. The species pass their egg and
larva state in the body of the mother, who produces only a
single egg at a time, which is in reality a pupa. This
pupa egg is nearly as large as its parent, and has a slight
motion, with spiracles, or rather spiraculiform points,
down each side, and in a short time it changes to a perfect

The Melophagus has no wings, but six stout bristly legs
with very long curved and toothed claws, which they fix in
the wool of the sheep. The head is very large, broader
than the thorax ; the antennae are mere tubercles ; the eyes
small, oblong, and bare. The mouth consists of a pair of
short hairy valves, in which a long sucking-tube is con-
cealed ; it usually uncoils in mounting, and is well seen as
a very fine hair, protruding from between the valves.

Objects for the Microscope.

149

STENOPTERYX.

This should be looked for on swallows: you may find them
abundantly in nests of the young birds. They run very
quickly, but do not attempt to fly, although they have
wings, and are good examples of another genus of the Hip-
poboscidse.

Here we find a difference in the male and female ; the
former having long narrow wings, ciliated in front, the
costal vein more than two-thirds the length of the wing, and
longitudinal veins crowded close to the costal. The female
has short triangular wings ; the rest of the body very like
that of Melophagus.

ORNITHOMYIA.

(. Parasite of Birds.)

A green and tawny fly, more perfectly winged than the
preceding genera, but seldom, if ever, using the wings, and
running with great swiftness amongst the feathers of all birds.

NYCTERIBIA.

This is a rare parasite, but quite worth seeking, upon
bats. The head is thrown back in an extraordinary manner ;
the mouth has a large bulb-like organ, from which proceeds
a horny style. It has no wings ; the claws are strong,
dilated beneath ; and the abdomen is terminated by two
styles. There are specimens of this in the British Museum.

CHELIFER.

This parasite attacks flies. I have seen a common fly
run wildly about the window-pane, shaking itself violently,
and apparently in great distress. Upon catching it, I
found a small scorpion-like creature fixed upon one of its
thighs, by a pair of tremendous claws, — hardly could it
be detached for examination, and then it ran quickly like a
crab, sideways. The Chelifer belongs to the Trachean
Arachnida , that is, they breathe by means of trachea and
spiracles, and not, as the higher order of spiders, by lungs,
or internal gills. They have eight legs, two long palpi
armed with claws ; the eyes are at the side of the thorax,
and the flat abdomen is jointed.

150

Objects for the Microscope .

ACARUS GAMASUS,

found abundantly on the Dung-beetle, which it infests.
This has a trifid labium, mandibles cheliform, denticulate,
the tarsi terminated by two claws, and an elegant pulvillus,
which make it worth mounting.

Scottish peasants have a habit of examining the Dung-
beetles in the spring, and observing the position of the
acari on their bodies : if the parasites are clustered near the
head, there will be a fine harvest, if towards the end of
the abdomen, a late one.

TROMBIDIUM PUALANGII.

A pretty little parasite, which attaches itself to the
Phalangium, or Harvest-spider. These spiders have small
oval bodies and very long legs, with two eyes on their backs,
and always run upon the ground ; we find these little scarlet
mites attached to their legs and bodies.

TROMBIDIUM AUTUMNALE.

( Harvest-bug .)

This troublesome little parasite is found in corn-fields in
August, and burrows in the skin, causing much painful
irritation. The best way of catching it is to tie pocket-
handkerchiefs round the legs, and walk through a stubble-
field, when we are nearly certain of finding specimens
enough in the folds of the handkerchief. They are mounted
in balsam.

In all the Trombidia, observe the form of the chelicerse,
with their moveable claw, and th e palpi, which have a sin-
gular appendage or finger beneath each extremity, which
distinguishes them from the common Acari, and show their
relationship to the pretty scarlet Water-mites, theHydrachna.

WATER-MITES.

( Hydmchnidce .)

The beautiful Hydrachna and Limnochares are parasites
upon the Water-beetle ( Dytiscus ), and Water-scorpion

151

Objects for the Microscope.

(. Nepa ), and worthy of attention in their metamorphosis,
also when mounted thus as objects for the microscope.

There are several species ; some bright scarlet (. Hydrachna ),
others dotted with black, having blue legs (/I tax), some
parti-coloured black and scarlet ( Diplodontus ), one, bright
green (Arrenus) ; all of them to be found in rivers and ponds
merrily swimming about, and laying millions of small red
eggs on leaf and stem of water plants. They seize on small
crustaceans, such as the Cyclops andDaphnia, and suck them.

The metamorphosis is as follows The eggs are laid in
great abundance throughout May and June, six weeks after
a curious larva comes out, having a long blue snout and
two large round eyes. We do not know how long it
remains free in the water, but towards the end of the
summer we find it change into a scarlet oblong pupa,
fixed by a strong hook to the tail of the Water-scorpion, or
under the elytra of Dytiscus. These pupse were once mis-
taken for eggs ; but the French naturalist Duges watched
them well, and saw every stage of the metamorphosis.
From the pupa emerges a six-legged mite, which moults
and becomes perfect, with eight ciliated legs for swimming.

The claws and palpi should be particularly noticed, and
the epidermis of the green mite Arrenus, mounted for its
dotted appearance.

ENTOZOA.

These are parasites attached to the internal parts of the
animal body, and consist of intestinal worms, some
extremely minute, burrowing in the skin, others of larger
size infesting the viscera. No part of the human body is
free from their attacks, the liver, the kidneys, the intestines,
and the brain, are their food and abiding-place. There is
scarcely one animal, especially of the vertebrate classes,
which is not infested by several species. The human body
has eighteen internal parasites, and those which inhabit
one animal are rarely found in one of another genus.
Those who desire further knowledge of these parasites, had
better read ‘ Owen’s Hunterian Lectures/ vols. iv., v., vi.

152

Objects for the Microscope .

CHAPTER VI.

MICROSCOPIC MOTHS.

“ Small fowl tliat sun their wings on the petals of wild flowers.”

Proverbial Philosophy,

A new class of objects, especially adapted for the
binocular microscope and a three-inch object glass, will
give the young student both surprise and delight, when
from his own researches he obtains these common and yet
little known Lepidoptera. Their history has been written
most ably by Stainton, in seven unattainable volumes, and
the ‘ Insecta Britannica’ has an extinct volume on the
Tiniena — at least it is out of print, and to be found only in
museums and the libraries of the subscribers, so that what
I now give is chiefly the result of my own observations and
collecting. I purpose a much more detailed account, with
illustrations, for “ the Intellectual Observer/’ at the proper
time.

One of the wonders of my childhood was the variety and
strangeness of the hieroglyphics I found on bramble-leaves
and rose-leaves, the white winding stream with a dark line
waving through it ; and after picking open several, and
finding within the small green caterpillars, and after often
gathering, and keeping them only to find the leaves wither
and the larvae die, I made small muslin bags, and covering
the mined and rolled leaves, I was rewarded by the perfect
insects, of such exceeding beauty as led me to renewed
attention and patient watching.

Every folded leaf, in truth, is the habitation of a micro-
scopic moth in its larval state, and beneath the leaf a blotch,
a pucker, or a tiny tent, will, if watched, give one of these
beautiful objects. They may be caught with a net, swept
off the bushes they frequent at certain times ; but they are
so very delicate and tender, that it is scarcely possible to do
*his without ruffling the beautiful plumage ; and I prefer

Objects for the Microscope. lo3

breeding them or collecting the grubs, and keeping them
under muslin shades, to ensure a perfect specimen.

I must, however, forewarn my young friends that every
leaf miner is not the larva of a moth ; for the primrose,
ranunculus, and several other plants, are mined by the
larva of flies, the Phytomyzides and Agromyzides.

The following list of the prettiest specimens will direct
the collector : —

NEPTICULA AURELLA.

This is the bramble-leaf miner. The parent lays an egg
on the under surface of the leaf, and as soon as hatched,
the larva, which is a very small caterpillar, with very
undeveloped legs, and no coronet of hooks on its fore-legs,
begins to bore through the cuticle and feed on the paren-
chyma, between the upper and under skin. As it feeds and
grows, the wavy line widens visibly, and along the centre is
a string of excrement, black and wavy also. When full
fed, it emerges and falls to the ground, spins a cocoon, and
changes to a pupa ; at the end of three weeks it rises as the
perfect insect, and flits over the brambles in calm, sunny
weather ; or we may find them in windy weather resting on
the sheltered side of a paling.

To the unassisted eye, this tiny moth is a mere brown
speck, a very dot of life. Placed under the microscope, we
see two upper wings of rich brown passing into deep
purple, and then a violet spot and band of brightest gold.
Two under wings of soft gray, deeply fringed with silvery
scales, and these scales are all remarkably large for tin
size of this minute insect, which does not exceed three line?
in length.

NEPTICULA MALVELLA,

is the moth of a small leaf miner on apple trees, in J uly anc
October, for all these little creatures have double broods
and its dark-brown upper wings are streaked with a singk
bright pale band.

NEPTICULA PRUNETORI.

Mines the sloe leaf, and has a beautiful dark wing, with
a well-defined black line preceding a silvery band.

10

154

Objects for the Microscope.

NEPTICULA TRIMACULATA,

the three-spotted moth of the poplar-mining caterpillar,
which deposits its egg on the upper, and not on the usual
lower side of the leaf, and makes a long gallery running
close to one of the ribs, then suddenly eats out a blotch.
The larvae are found in July and October ; the moth in
May and August, easily recognised by the broad, whitish
streak, taking up half the breadth of the wing, with two
triangular whitish spots beyond the middle.

But the microscopist need not go further than the common
laburnum for one of the prettiest— nay, it is a lovely little
creature, that glistening, white-winged

CEBIOSTOMA.

Those unsightly blotches on the leaves are the abode of
its larva ; and we lament over the spoiled and crumpled
laburnum leaves until we have learnt the life of that most
beautiful little moth. The upper wings are pure white,
with a pale yellow spot on the costa beyond the middle, and
a second spot with parallel lines ; then, near the tip, a large
black spot with violet pupil, and three radiating brown
streaks in the cilia. No large butterfly is so beautiful.

There is another Ceriostoma, so like the first as scarcely
to be distinguished, and yet it has a variation, and is one
of the manifestations of design and order that I cannot but
draw attention to. It mines the broom plant, and is
easily taken from the middle of June to the end of July.
The upper wing is like that of the laburnum miner, except
that the second dot has always converging , and not parallel
lines— that is all ; it is but the bending of a narrow line,
invisible to the naked human eye, yet there it ever is, drawn
by the Hand whose lightest touch hath purpose and per-
fection of design.

Another species, perhaps lovelier still,

CERIOSTOMA SCITELLA,

mining the hawthorn, the apple, the pear, blotching the
leaves and making our hedge-rows wither before their time.
How exquisite is the soft gray wing of this species, mottled,
fretted, banded, and streaked, with a golden tinge around

Objects for the Microscope.

155

the large violet eye, like a microscopic Peacock Butterfly,
but far more beautiful. This well deserves careful mounting.

But as my space is limited, I must not enumerate many
more of these moths, for it is only to give an impulse to
the study of them that I write so much, and to suggest
them as new and interesting objects for the microscope.

There are no less than seventy species of Lithocolletis,
whose brilliant gilded or silvered wings have given them
the appellation of the Humming Birds of the Lepidoptera,
and it will well repay any trouble to obtain the following
species : —

LITHOCOLLETIS SYLVELLA.

Abundant on the maple, and found near London, Ten-
terden, Guildford, Oxford, Bristol and Shrewsbury. The
pure white wings have ochreous fans, bent into angles, and
edged with jet-black scales.

LITHOCOLLETIS SCHREBERELLA.

The larva puckers the under side of elm leaves, and the
perfect insect flits to and fro, with bright-reddish, orange-
coloured wings, striped with silver glittering bars, and with
a pair of silver dots. These are very abundant near London
and Oxford in May and in August.

LITHOCOLLETIS TRIFASCIELLA.

Whoever cares to find this, need but observe the lower
leaves of the honeysuckle shoots in April, all puckered
aslant , and the under side mined. Three broods in the
year does this honeysuckle feed, and around it will flit the
moth with reddish-yellow wings and white bands, deeply
bordered with black scales. This also is common near
London.

LITHOCOLLETIS HORTELLA. — L. ROBORIS. — L. AMYOTELLA.

These all mine oak leaves, and have very pretty variegated
wings, white or yellow, and with golden-brown bands and
dots, and delicate gray under wings, with white cilia.

The collector must also seek the leaf rollers as well as
the leaf miners.

156

Objects for the Microscope.

GRACILLARIA SWEDERELLA,

common on the oaks in May, June, and August. The
upper wings bright-reddish, with a violet gloss, pale-yellow
streaks, and triangle, and under wings of shining gray.
This pretty little creature sits upon its tail when at rest,
with a smooth head and its long antennae folded back ; not
difficult to catch.

GRACILLARIA SYRINGELLA.

Abundant in gardens where lilac trees s ufferfrom the
rolling up of the leaves, and the little chocolate-variegated
moth comes forth to give another brood to the already
disfigured trees.

COLEOPHORA GRYPH1 PENN ELLA.

There are about forty-one species of these moths whose
larvae make tents in the most ingenious manner, eating away
the parenchymae of a leaf until enough is hollowed out for
a convenient habitation, and then joining with silken threads
the upper and lower cuticle, they cut it quite out and walk
off with it. These are found commonly on rose trees in
May, and the little moth in June. Other species on
Stellaria, Sallows, Hawthorn, Ground Ivy, the Pear, the
Plum, and the Cherry in May, when the pupa cases may
be collected and the moths taken.

ORNIX GUTTEA.

A pretty spotted moth whose larva folds down the edge
of apple leaves and feeds there.

LITHOCOLLETIS SCABIOSELLA.

In the herbage near scabious plants this pretty species
will be found and easily taken.

It is reddish-saffron coloured, the upper wings with three
pure bright white stripes, edged on the inner side with
black scales, and there is a double spot at the apex of the
wing, white also, but with a stream of black scales, spreading
fail-like towards the edge. The larva of this Lithocolletis
crumples up the root leaves of the scabious by mining the
under surface of the leaf, and in the shelter of its excavation

157

Objects for the Microscope .

spins a slight cocoon where it undergoes its transformation.
This moth is plentiful in the neighbourhood of Croydon.

GLYPHIPTERYX THRASONELLA.

Several of these are the prettiest little green moths flitting
in open meadows, and one species, haunting the rushes in
damp places, has, upon the dark-bronzy, green ground, five
bluish silvery streaks, and above the anal angle a black
blotch, enclosing three silvery violet spots. The wing is deeply
edged with bronzed cilia, and the under wings are gray.

Another extremely pretty species is , found in June and
July flying over the flowers of Stonecrop — this is Glyphip-
teryx equitella.

Enough, perhaps, are now described, yet I would draw
attention also to the form of the heads, the feathered
antennse, and the tufts of scales on the heads and palpi of
many of these moths. For instance —

THE HEAD OP OCHSENHEIMERIA,

feathered in a marvellous bird-like manner, the antennse
thickened with scales, labial palpi very hairy, and the
head alone making an excellent object. The moth is gray,
and very abundant in some meadows towards the end of
July. They are rarely seen, however, except between the
hours of twelve and two, in the heat of the sun, and then
they are hopping about the grass stems, and depositing
eggs on the stems of Dactylus glomeratus.

The heads of the following are remarkable, and worth
mounting : —

HEAD OF PLUTELLA,

with tufted labial palpi.

The moth is spotted gray, and is often very abundant
among cabbages and cruciferous plants.

HEAD OF CORSICIUM.

This should show the front of the head, and the curved
labial palpi, with long pendent scales. The moth is grayish-
brown, and hovers about oak trees in June, August, and
September.

158

Objects jor the Microscope.

CHAPTER VII.

PALATES.

PALATE OF HELIX POMATIA.

Helix pomatia is that very large snail found in woods
and hedges on chalky soil and oolite formations in the
Southern and Midland Counties of England. The shell is
often two inches high, of pale tawny colour. These snails
were highly esteemed in the olden time by the imperial
gourmands of Rome, who preferred them fried in oil of
almonds, and then delicately grilled on a silver gridiron.
When previously fattened upon bran and wine, they grew to
an enormous size ; three snails, two eggs, and a lettuce, being
a favourite supper of Pliny the younger. At one period in
England we feasted upon them ourselves, boiled in spring-
water, and seasoned with oil, salt, and pepper ; and highly
relished them as a foreign luxury, introduced for that pur-
pose about the middle of the sixteenth century, and first
cultivated in Surrey, afterwards in Buckinghamshire and
Northamptonshire. Of later years they have been used
medicinally in cases of consumption, as also the common
garden snail, Helix aspersa, which is exported from England
yearly for this very purpose, and sent to America packed
in old casks. The glassmen at Newcastle have still a snail-
feast yearly, and generally collect the snails themselves on
the Sunday previous to the feast.

We may also care to know that this edible snail, which
abounds in the neighbourhood of Mount Sinai, has been
thought to have supplied the Israelites with food in that
part of their journey towards the land of Canaan ; for the
whole sides of that valley between Mount Deouchi and

159

Objects for the Microscope.

Mount Torah are covered with shrubs of tamarisk broom,
and with clover and saintfoin ; and the herbage beneath is
so thronged with these snails that travellers say it is diffi-
cult to walk without crushing them.

So much for the general interest of the snail ; but the
palate chiefly relates to its depredations, and shows us the
cause of its mischief-making in our gardens.

HELIX ASPERSA.

The mouth of the snail is armed with two horny lips,
sufficiently powerful to bite the tender stalks of lettuce and
other young vegetables ; and is further provided with this
palate, which is not in the mouth, but lying far back in a
kind of pouch which opens in front, and is capable of pro-
jection forward and backward, as may be well observed in
the water-snails kept in aquariums. We can there see the
opening lips and the palate thrown forward, rasping away
the conferva spores on the surface of the glass. The
palate of Helix aspersa is broad and short, set with about
150 rows of stout serrated teeth— altogether no less than
21,000 in this single palate.

LIMAX,

(Black- slug,)

is nearly the same, but contains yet more teeth. A full-
sized and aged slug has 26,000 teeth, which accounts for
its power of destruction in our gardens.

IIELTX HORTENSIS.

Helix Hortensis is a variety of the common garden snail,
reddish, yellowish, or pale gray.

HELIX NEMORALIS.

Helix nemoralis is the pretty banded black and yellow
snail, which, if long lying in the warm sun, often turns
rose-coloured or fine pink, to the great admiration of little
shell collectors.

160

Objects for the Microscope.

HELIX RUFESCENS.

Helix rufescens, a reddish-brown snail, flatfish, and in
the middle of the largest whorl it has a narrow white line
or band, which distinguishes it.

HELIX VIRGATA.

These pretty small brown and white banded snails are
most abundant on our sandy sea-coasts, quite covering the
marine plants there ; also they are often in great numbers
on sandy commons on the wayside turf.

The palates of all these terrestrial gasteropods are upon
the same plan — broad, short, and with long rows of teeth ;
the prettiest variety is found in the palate of

ZONITES, OR HELIX NITIDA.

This small snail is a species passing out of the genus
Helicidee ; it is small, transparent, pale yellow, or light
brown, with five whorls, and the under side clouded with
white ; found under stones, and in violet beds at the roots
of the plants, also in cellars and yards in cities. The side
teeth slope towards the centre, which is occupied by what
maybe called double teeth, or teeth with several projections.
There are few prettier palates than this of the common little
Zonites, or Cellar-snail.

PALATE OF WHELK.

(Buccinum undatum.)

Compare this with the palate of any of the terrestrial
gasteropods — snails or slugs — and the difference of struc-
ture will be apparent : instead of that broad short mem-
brane thickly set with rows of nearly uniform teeth, we have
here a ribbon-like tongue, having strong serrated teeth at
the edges, and rows of small finer ones between them, better
observed by polarized light, which makes it a splendid
object. This tongue is contained in a long fleshy proboscis,
with which the Whelk bores through the shell of those
molluscs which serve it for food, and the muscles by which
it moves this tongue are immensely strong, not only drawing

Objects for the Microscope. 161

it backwards and forwards, but raising or depressing the
teeth.

The whelk is largely consumed in London ; it is dredged
off every part of the British coast. Dr. Johnson tells us
that at the enthronisation feast of William Warrham,
archbishop of Canterbury, in 1504, 8,000 Whelks were
dressed as side dishes for the lordly epicures of those
days.

PALATE OF PURPUREA.

The Purpurea, or Dog-whelk, is a small species of Buc-
cinum very abundant on our rocks ; it has a white shell,
and is often found with a little semi-transparent flask beside
it, or a cluster of them filled with eggs, which are most in-
teresting microscopic objects, as the development of the
little mollusc is easily watched. The palate is pretty and
resembles that of the larger Buccinum. It was from this
shell-fish that the Tyrians procured their famous purple dye,
making a bath of the liquid in the proportion of two pounds
of Buccinum liquor to one pound of the purpurea. The
process being tedious, and the needful quantity of these
little creatures very great, the price of the wool so dyed
was enormously high — no less than 1,000 Roman denarii,
or thirty-six pounds sterling, per pound.

NASSA.

A smaller species of Buccinum.

PALATE OF TROCHUS ZIZIPHINUS.

This is the palate of that very pretty variegated spiral
shell called “ Tops,” which we delight to find on the rocks
at low water under the thick hanging masses of sea-weed.
No palate is so beautiful, or requires such careful exami-
nation ; for when we have had a general view, we should
always use a higher power, and explore further the won-
derful workmanship displayed in this tiny tongue. Not
only are there triple rows of finely notched teeth arching
over towards the centre, but the intermediate space is
thronged with delicate leal-like teeth, curved downwards

162

Objects for the Microscope.

with minutely serrated edges — making a powerful instru-
ment for rasping the surface of the sea-weed upon which
the Trochus feeds.

The mouth (of the Trochus) has no upper horny plate,
and therefore probably needed this elaborately toothed
tongue.

PALATE OF TROCHUS CRASSUS.

Trochus Crassus is a variety of the same family, having
a large gray shell, and the tongue less beautiful.

PALATE OF TROCHUS UMBIL1CATUS.

Trochus umbilicatus; a smaller and more abundant shell,
also of gray colour.

PALATE OF PERIWINKLE.

(Littorina.)

The Periwinkle is too well known to need description,
and the palate is very like that of the Irochus Crassus.

PALATE OF HALIOTIS, OR AUMER.

The Haliotis is that beautiful univalve mollusc found in
the Channel Islands, under stones at low tide ; the fleshy
foot is sold in the market there, and highly esteemed as an
article of food, either stewed or fried in batter. The shell
is brought to England, and sold to manufacturers of works
inlaid with so-called mother-of-pearl, which is really the
beautiful interior of this shell. The palate is one of the
finest prepared for the miscroscope, and yet more compli-
cated than that of Trochus ziziphinus , which it resembles.
The central band here has rows of teeth, having nearly
straight edges instead of points ; there is on each side a
lateral band consisting of large teeth, shaped like those of
a shark ; and beyond this, again, another lateral band on
either side, composed of several rows of smaller teeth. (See
‘ Carpenter on the Microscope/ p. 605.)

The Haliotes are carnivorous as well as vegetarian, often
found feeding on dead bodies.

Objects for the Microscope.

163

PALATE OF PLEUROBRANCH.

The Pleurobranch is a lemon-coloured, oval-shaped mol-
lusc, found under stones in tide-pools, and breathing by a
beautiful branchial plume, which is thrown out on the right
side, as it glides along, and protected, when at rest, by a
thin shell inside the mantle. This palate is quite unlike
any of the others, more resembling a tesselated pavement,
with a single tooth in each lozenge-shaped division.

PALATE OF APLYSTA.

Aplysia is a sea-slug, found in deep rock-pools gliding
about with a thick hump-backed body, olive-brown, and
tentacles like ears, causing it to resemble a hare. If
handled or frightened, it jerks forth a deep purple liquid,
which stains the hand or discolours the water. This is
evidently its defence, and conceals it from the pursuit of
ravenous crustaceans. It belongs to the family of the
Pleurobranchs, which have their breathing organs con-
cealed within the mantle, but always on the right side , and
the palate is broad and short, resembling that of the garden
snail, only very much larger.

PALATE OF DORIS.

( Tuberculata .)

Another variety of sea-slug, much more beautiful, and
the palate curiously set with strong hooked teeth like a
harrow ; it has forty-four rows, each with 140 of these
curved teeth, used for rasping sea- weed. There are many
species of Doris usually found under stones at low tide, or
beneath tufts of sea-weed ; they are orange-coloured, or
pale-yellow, and vary in size from our largest garden slug
to a very small one ; on their backs they carry a plume of
branchial organs, and are therefore called Nudibranchs, or
naked-gilled animals.

PALATE OF LIMPET.

Who does not know the Limpet, clinging to the wave-
beaten rock, and seemingly as motionless as its native cliff?

164

Objects for the Microscope.

— who has not jerked it off for bait or for the variety of
colour in its pretty shell, and in so doing noticed a long
slender thread attached to its head, and many times longer
than its body ? That was the tongue we are looking at.
It has, we see, alternate rows of four hooked teeth, and
two notched large teeth all the whole length of that thread-
like palate, which lies coiled up loosely inside its body, and
is thrown forward like a scythe to mow down the lichen
upon which it feeds. When the front row of teeth wears
away, a second is brought forward, and so the length of the
tongue only provides for the little creature’s necessities and
duration of life.

PALATE OF CHITON,

Not so abundant, and very different in formation, is the
Chiton, which we find hidden in crevices of the same rock
to which the Limpet clings. The Chiton is the only mol-
lusc which has many shells in one. This little creature has
eight plates or shells overlapping each other, round the
external edges of which the breathing organs lie, — a row of
triangular leaflets vibrating in the water, and resembling
gills in structure. The palate we see is long and ribbon-
like, with dark-brown teeth on either side, and smaller in
the centre ; they are set in a kind of double arch, jointed,
and capable of elevation or depression, and used, like those
of the Limpet, for vegetable food.

PALATE OF YELLOW NERITE

is very pretty, and somewhat like the Periwinkle. The
Nerite is that bright-yellow shell so common on our sandy
coasts. Children call them “ yellow tops.”

PALATE OF NERITINA FLUVIATILIS
is a fresh-water mollusc, found in slow rivers adhering to
stones, the shell very prettily chequered with spots or bands
of white, brown, purple, or pink.

PALATE OF LYMNJ3A STAGNALIS.

The three following palates belong to fresh-water
molluscs.

Objects for the Microscope . 165

Lymnsea is a large snail, whose shell, making six or
seven whorls, terminating in a fine point, is found in all
ponds and stagnant water, floating or gliding foot upwards,
and feeding voraciously on all kinds of vegetable matter.
The palate resembles that of the garden snail.

PALATE OP PLANORBIS CORNEA.

Planorbis is a flat snail with a shell in horizontal coils,
the size of a shilling, other species being smaller. The
tongue is oblong, and set with many rows of fine teeth.

PALATE OF PALUDINA.

Paludina is a remarkable fresh- water shell, more resem-
bling a large Periwinkle, but banded black and yellow,
with a strong operculum. It brings forth its young alive,
and they may be found in all stages of life in the space
between the mantle and the shell. The tongue of the Palu-
dina differs much from those of Lymnsea and Planorbis,
being long and slender, and the teeth like horny plates
laid over one another — more like those of the land-snail,
Cyclastoma, and showing that it is, in truth, as La Mark
conjectured, the family which links the two great divisions
of land and water molluscs. Here then we have a very
interesting palate, and proof of the usefulness of microscopic
observation ; for nowhere but in the palate do we find the
very marked distinction between the Paludina and Lymnsea,
both inhabitants of the same stream, and at the same time
the close relationship to the little Cyclastoma, which lives
high and dry upon the chalky hills, and under the hedge-
rows of a limestone district.

PALATE OF CYCLASTOMA.

The Cyclastoma elegans has a white and finely striated
shell ; its palate should be mounted in fluid, as indeed all
these are. Simple salt and water well preserves them.

166

Objects for the Microscope .

CHAPTER VIII.

SLIDES OF ZOOPHYTES.

“ O Lord, how manifold are thy works ! in wisdom hast thon made
them all : the earth is full of thy riches. So is the great and wide sea,
wherein are things creeping innumerable.”

Psalm civ. 24, 25.

“ Look who list thy gazeful eyes to feed
With sight of that is fair : look on the frame
Of this wide universe, and therein read
The endless kinds of creatures which by name
Thou canst not count, much less their natures aim j
All which are made with wondrous wise respect,

And all with admirable beauty deckt.”

Spenser.

An explanation of these useful slides to every sea-side
student seems necessary, from the fact that many persons
inquire, “ What is a Zoophyte ?” and if shown one of these
under the microscope, will presently declare that it cer-
tainly may be an animal, for it moves. This has happened
to myself more than once, and an explanation required to
prove the fact is a post-mortem examination, and then we
only see the body, or rather the framework, which sup-
ported the once living polype.

These are the skeletons of Zoophytes mounted to show
the beauty of their structure, and the variations of form
which determine the species.

If we would see them alive, we must gather them at the
sea-side fresh from their native element, on the sea-weed
or the rock, and by placing them in a watchglassful of water
under the microscope, the question “ What is a Zoophyte ?”
will be answered far better than any tongue can tell or pen
describe. Nevertheless, to appreciate these slides we must
explain that Zoophytes are, with one exception, marine
animals, varying in size from the little microscopic creatures
mounted here, to the large tree-like Gorgonias, and the
huge Madrepores and Corals of the tropical seas. They
are plant-like animals, often mistaken for sea-weeds,

167

Objects for the Microscope.

requiring minute attention and microscopic study to un-
derstand ; but even the careful observation of those speci-
mens on our lists will open a wide field of interest, and help
the young student considerably in his first researches.

The number of British Zoophytes amounts to about
35 genera, and 240 species. These are divided into two
great divisions, and hold very different ranks in the scale
of creation ; for the Zoophytes called Polyzoa, being much
more highly organized than those called Anthozoa, they
are placed with the Tunicate Molluscs (Ascidians, &c. &c.),
and above the Radiata (Starfish and Echini) ; whereas the
Anthozoa are only just above the Infusoria, or lowest form
of animal life.

These slides contain specimens of both these orders,
which will be further explained when under the microscope.
Those of the Anthozoa are —

Sertularia.

Plumularia.

Laomedea Campanularia.
Tubularia.

Coryne.

Halecium.

Thuiaria.

Antennularia.

Their bodies are globular, contractile in every part,
symmetrical, mouth and vent one, gemmiparous and
oviparous. The Polyzoa are —

Gemellaria.

Cellularia.

Crisea.

Elustra.
Pustulipora.
Lepralia.

If we describe the Sertularia as an example of Anthozoa,
and Gemellaria as one of the Polyzoa, the student will
understand each of the others, and when at the sea-side
will have ‘ Harvey’s Sea-side Companion,’ or 1 Landes-
borough on Zoophytes,’ to teach the variety of the species,
and direct to their particular habitat.

ANTHOZOA.

SERTULARIA PUMILA.

This little branch of zigzag cells was once creeping
along the Pucus, or common sea-weed, on rocks at low-
water mark, often so thickly crowded together as to cover
the alga. The cells are opposite each other, and at inter-

163

Objects for the Microscope.

vals large capsules or ovarian vesicles rise from the base of
a smaller cell. In life this horny skeleton was filled with
a living pulp, and each tiny tube right and left was the
abode of a beautiful white creature called a Polype, which
rose up and threw out eight or ten fine tentacula, or
feelers, drawing food into a mouth placed in the centre of
these tentacles. From the mouth there was a digestive
sac, or stomach, communicating with the stem, and a cir-
culation of fluid went on throughout the polypidom, that
is to say, the branch of cells we have described, though
each Polype had an independent life.

It has been observed, that at the base of the Zoophyte
stomach there is an orifice closed by a contracting and
dilating sphincter muscle, and through this the digestive
food is propelled to the stem, after enough has been appro-
priated by that Polype, besides which a spiral movement
of particles is seen in the stem, somewhat resembling the
rotation in Chara.

The manner of propagation and of growth is very
remarkable. Those ovarian pear-shaped vesicles you may
see here and there on the branches contain buds, or
gemmae, which, when mature, escape and swim freely in
the great ocean. Their form is most unlike that of their
parent ; they are called Medusyides, and in turn produce
fertilised ova ; these being edged with cilise move for
several hours in the water, and then, fixing on sea-weed,
rock, or stone, develop into a polypidom like this spray
of Sertularia. When the ovule fixes, minute fibres are
observed to proceed from the under side, and the pulp
dilates and ascends, covered by the horny substance, inside
which the dark pulp runs like a thread. At a certain fore-
ordained point it stops, becomes bulbous, a tube or cup
(according to the species) forms gradually, whilst the pulp
is fashioned into the Polype with little knobs lengthening
into tentaculse, which no sooner are complete than they are
thrown forth for food ; and the nourishment, instead of
increasing the size of the Polype, is passed to the stem,
and a second cell buds forth on the opposite side, or the
stem is prolonged a little, according to the plan of the
species. Look at the next slide —

B’HAM. FIELD

DIGBETH IN8T1TUTE.

C) OB LIBRARY Objects for the Microscope. 169

SERTULARIA POLYZONIAS.

You see here that the Polype cells are not opposite each
other, but alternate and far apart. There are two varieties
of this Zoophyte, the one upright, the other spreading
and branching ; it is found on shells and sea-weed, especially
on branches of Halidrys.

These little creatures are very phosphorescent in the
dark ; if we shake or strike the sea- weed upon which it
rests, a shower of diamond sparks seem to be scattered over
the frond ; each cell on the delicate spray is a fairy lamp, a
moment seen and gone, or sometimes shining on with a
faint, gentle light, showing where the little Zoophyte is
dwelling. Often when, having gathered a quantity of Ser-
tularia pumila during the day, I have handled it at night,
the flashing out of a thousand tiny stars has astonished me.
What must it be if the tossing wave shakes glory thus from
the dark weed in the stormy night, and the ocean depths
are illuminated by their living lamps ?

SERTULARIA OPERCULATA,

or Sea-hair Coralline, shows the sharp tooth-like cells
peculiar to this species, and the vesicles with a rounded
operculum on the top. This zoophyte is abundant on the
coast, often thrown up on the beach in tufts as much as
six or eight inches long, especially after a storm.

SERTULARIA ROSACEA,

called the Lily or Pomegranate Coralline, will give you a
good specimen of varieties in species, and show you what to
observe ; for the cells are not so unlike those of the common
Sertularia pumila (the upper part of the cells bent out-
wards and downwards slightly), but the vesicles are most
unlike. You see they are pear-shaped, wrinkled, cleft at
the top, and more silvery in hue. This coralline grows on
shells in deep water, and is parasitic on other zoophytes,
small white clusters being often found on Plumulariafalcata
and Sertularia argentea.

LAOMEDEA GENICULATA,

the Knotted-thread Coralline — a very common and beau-

11

170

Objects for the Microscope .

tiful zoophyte, one of the family of Campanularidae, and
worthy of minute examination. In this species we are
successful in preserving the polypes themselves inside those
tiny cups. The fibres are twisted in a network on the sea-
weed— usually a frond of Laminaria or Fucus, and slender
threads bristle thickly from the stem — a zigzag line, on
each side of which rise winged stalks bearing the polype
cell ; here and there are large vesicles containing Medu-
soides. The peculiar interest of these Laomedea is the
wonderful adaptation of their structure to the element in
which they live. How would this fragile cup and slender
stem resist the wild storms of the ocean if it had not been
provided with that jointed pedicle, which bends to and fro
on every side in ease and safety, whilst the little inhabitant
stretches forth its single row of tentacles, and draws food
into its probosciform mouth ? The vesicles also, though
apparently sessile, are fixed upon a footstalk like a screw,
which enables them to resist the shocks of a stormy sea.

LAOMEDEA DICHOTOMA.

Laomedea dichotoma, or Sea-thread Coralline, is found in
long, filiform, zigzag branches, on old shells or stones, or
sea-weed, within tide-mark.

PLUMULARIA CRISTATA.

Observe this both with reflected and transmitted light.
It is the Feather Coralline picked up as sea-weed by chil-
dren on the sea-coast, after a gale of wind has cast up
treasures of the deep within our reach. It belongs to a family
(. Plumularta ) which has several species, but none so beautiful
as this. We find it twined round the stems and pods ot
Halidrys siliquosa ; sometimes a mussel-shell will have a
feathery plume upon its rich blue surface, and tens of thou-
sands of tiny creatures spring forth from those sessile cups,
ranged all along the pinnae , they are shaped somewhat like
lilies of the valley, with a projecting spine beneath each, and
the vesicles are oblong, pod-like, and banded with cristated
ribs ; the more of these, the better the specimen ; but it
should be examined when fresh, and is more easily found,
perhaps, than any other zoophyte.

Objects for the Microscope .

171

PLUMULARIA FALCATA

is another species, in which you may observe the polype
cells seated in close array along the pinnae of the branches ;
these, when dry, bend inwards like a sickle, and give the
name of Sickle Coralline to this zoophyte. It is dredged
in deep water, and common on oyster beds. A wavy branch
of it will not unfrequently be found on the back of some old
crab, which has served as its perambulator, and carried it
into rich stores of Diatoms and Infusoria, such as it
delights in.

POLTZO A
GEMICELLARIA.

This is one of the Polyzoa, more highly organized than
Sertularia, &c., and therefore ranking considerably higher
in the scale of creation. The difference in the skeleton
here prepared is, that we have a calcareous cell instead of a
horny one. Almost all the Polyzoa have calcareous sheaths,
or polyzoaries, as this skeleton is called, instead of poly-
pidom, which belongs to the lower class of zoophytes. The
difference between the two is this : a polypidom is a sepa-
rate horny case, which is formed before the indwelling and
connected polype, and the polype itself is part of a common
central mass, having a simple stomach, thread-like tenta-
culse, which seize food and draw it to the mouth, and
which multiply by ovarian vesicles containing medusoides.
The polyzoary is a case or tunic investing the body of a
distinct and separate polype, which is either horny or cal-
careous, sometimes forming a dense hard crust on stones
and shells.

The polype within is quite different from that of the
Anthozoa. It has ciliated tentacles. The Polyzoa is a
part of the polype itself, investing it as a tunic or case,
which is sometimes horny, but most frequently calcareous ,
even forming dense crusts upon shells, stones, or sea- weeds.
Though always found in a mass, the Polyzoa are strictly
solitary individuals, without inward connection, each polype

172

Objects for the Microscope.

being perfect in itself, and distinguished from the Anthozoa
by that of its ciliated tentacles, which do not seize the prey,
but create currents in the water whereby food is carried
into the mouth.

This is a great distinction, and must be observed, of
course, in the living animal ; a very curious sight it is to
watch the shoals of little golden fish-like naviculse whirled
into the vortex of a hungry polype, the currents running
along the cilia or delicate fringe which edges each tentacle.
Some polypes have two stomachs, one a kind of gizzard,
triturating the food, and the other digesting and discharging
the refuse. There is even a rudimentary liver — a valve at
the pyloric opening ; the stomach itself is lined with cilia ;
in short, the living polype you are now looking at in
its dead state was a wonderfully organized little creature,
though scarcely visible to the naked eye. Instead of the
ovarian vesicles of the Anthozoa we find, especially on
Flustra and Lepralia, little pearly cells, which are gemmae,
or buds, thrown forth from the body of the polype. They
have two methods of propagation, one by gemmation, the
other by a true sexual generation. ( See 1 Carpenter on the
Microscope,’ p. 575.)

MEMBRANIPORA PILOSA.

An abundant and beautiful zoophyte for examination in
the living state, as the fearless little polypes rise up in
crowds from the shelter of their pearly homes, and fling forth
their white ciliated tentacles, waving, curling, contracting,
and expanding, in very ecstasy of life, drawing in the food
they require by means of the currents these tentacles make.

In this living state the Membranipora is only a brown,
thick crust on rock or sea- weed ; but when the zoophyte is
dead, we find it on the brown fucus or the crimson Deles-
seria, or sheathing the stem of Chondrus crispus, like a
delicate net, pure white, or pale fawn colour; when mounted
dry it is perfectly lovely. We now see the oval horizontal
membranous cells, sharply toothed and granulated, whilst
behind the mouth of each is a long jointed bristle, which
in life lashed the water to and fro, keeping the Polypidom

173

Objects for the Microscope.

free from obnoxious particles. If, however, the observer is
at the sea-side, whilst examining a living Membranipora, he
may look for the singular organ described by Dr. Earre and
by the Rev. T. Hincks. It is oblong, placed between the
base of two of the arms, and attached to the tentacular
ring. Round the opening at top is a play of cilia, and it is
lined with cilia. These gentlemen observed numbers of
filamentous bodies wriggling up from the visceral cavity, and
as they reached the base of this organ, they were drawn into,
carried upward through the ciliated channel, and ejected,
being then whirled away by the tentacular currents. These
are supposed to be spermatozoic bodies called cercarise, and
subservient in some way to the function of generation.

Besides Mebranipora, I would direct attention to various
species of Lepralia. Scarcely a stone or a shell from the
great deep but yields most varied forms of these zoophytes.
In the Channel Islands, Jersey, by Mrs. Gatty, of Eccles-
field, Guernsey, on Phylophora rubens, and also at Sidmouth,
the loveliest species called

LEPRALIA GATTYiE,

may be found in winter thrown up after a storm, exceeding
small — a little branching speck, once seen never forgotten,
differing from all other Lepralia in having a rich pattern
carved upon the centre of each cell. A raised knob and
a circlet of dots, then rays or raised lines, between each of
which is to be found a dot or puncture larger in size than
those of the other circle ; again, the termination of each
cell is delicately fluted, that is, if not overcrowded with cells
or ovarian capsules. In all Lepralia we find round, pearly,
smaller cells, dotted over the surface, sometimes almost
hiding the parent cells ; these are most abundant on the
pretty

LEPRALIA HYALINA,
common on mussel-shells.

LEPRALIA NITIDA

is like a miniature human thorax, ribbed and with a broad
band representing the sternum ; a lip armed with five long

174 Objects for the Microscope.

spines, and having a metallic glow over all the pure white
fabric.

The observation of a few specimens will lead to a large
collection ; not a speck upon sea-weed, stone, or shell, should
be overlooked, and for a pleasant, easy guide, take ‘ Dr.
Landesborough on Zoophytes.’

ALECTO GRANULATE.

This is found creeping on stones and shells and weed
dredged from the deep ; cells tubular and creeping, four or
five abreast, with long spines, and granulated texture and
erect circular aperture. Alecto major has no granular
markings. This zoophyte, amongst others, is sold by
Baker, and a collection would be found most useful pre-
paratory to further researches at the sea-side.

GEMMELLARIA LORICULATA.

This Gemmellaria loriculata is an example of the branched,
half-horny, half-calcareous polyzoary ; it is a splendid
object with polarized light, if mounted in balsam, the
cells pale pink, with a framework of carbonate of lime,
giving a fine orange tint.

We find Gemmellaria abundantly on the south-western
coast, or thrown up on the beach, after a gale, in bunches,
easily distinguished by the position of the cells back to
back in pairs.

GEMECELARIA, OR NOTOMIA BURSARIA,

a rare but lovely zoophyte, always to be looked at as
opaque, and the singular appendages to its lid observed.
The triangular cells are in pairs, each capped by an organ
resembling a tobacco-pipe, or, some say, a bird’s head. It
is also called the Shepherd’s Purse Coralline, from its
resemblance to the seed-capsules of that plant. We only
find it in very small tufts, parasitic on other zoophytes ; but,
minute as it is, the tiny creature has the same highly
organized body as the rest of the Polyzoa.

CELLULARIA AVICULARIA

is the true Bird’s-head Coralline found on stones in deep
water or at very low tides, growing in spiral fan-like tufts
about an inch high. This is a calcareous polyzoary : the

Objects for the Microscope

175

cells have a spine at each upper angle, and an appendage
called the bird’s head. With a little management of light,
you will see the muscular lines by which the neck opens
and shuts ; when alive it snaps in all directions, seizes any
passing animal, and holds it fast until death. Now, as they
have no inward connection with the stomach of the polype,
neither give the food to the tentacles, it is doubtless lor
protection that they are placed over the otherwise defence-
less zoophyte — a sensitive and ever-ready police to keep
the cities of the great deep. Cities they are indeed ; for
examine a piece of Flustra —

FLUSTRA TRUNCATA.

On one specimen you may count 18,000 inhabitants, all
rejoicing in the life bestowed upon them, and all in obedi-
ence and harmony performing their task in the ocean world.
Yes, they all have an appointed work — they had it long
ago in the ages beyond our own existence — before the
green earth had risen from the chaos of waters, or even
before the Saurian age of reptiles, in the calm clear ocean
of the earliest formations, the little polyzoaries of these
zoophytes existed, and their fossil forms are found with
those of the lonely Trilobite.

It is possible to mount these zoophytes with the polypes
displayed, and a more beautiful object is rarely seen. The
way to manage it is thus : Watch the living creature placed
in a shallow dish of its native element, and whilst they are
“ out” dash in a tumbler of cold spring water, which
paralyses the Polypes, and they may be mounted in fluid
permanently. Another way I have heard, but not tried, is
to pour gently some spirit into the water, which irritates
the zoophyte, and it comes forth to drink of the intoxicating
fluid, and falls a victim to its poisonous influence.

PUSTULIPORA FOSSIL,

of which the present species are Pustulipora, Deflexa , and
Proboscidia ; calcareous, erect Polyzoas, with tubes halt
immersed ; found on shells in deep water off Plymouth and
Zetland ; whilst the fossil slides sold by Tennant are from
the chalk of Kent and Wilts.

176

Objects for the Microscope .

FLUSTRA CHARTACEA

abounds at Hastings ; thin, glistening, and scarcely two
inches high, of a light straw colour ; the cells are an oblong
figure, protected by a helmet-like operculum. Called also
the Paper Seamat.

The name Fliistra is from a Saxon word jiustrian , to
weave ; and wonderful, truly, is the living web which the
Almighty hand has woven in the deep sea !

CELLULARIA REPTANS.

{Creeping Cellularia.)

The Cellularia polyzoa has a mixture of horny and cal-
careous matter ; the cells have an oblique opening, each
with four or five short spines : it is a very common species
on fucus, in circular branched tufts.

CELLULARIA CILIATA.

A delicate little pearly-white coralline, often found amidst
the bunches of red sea-weed — the Ptilota sericea espe-
cially. The cells are at the tips of the branches, and armed
with five very long calcareous spines, which are so brittle
that you seldom get them mounted perfectly ; and over
the mouth a most exquisite little operculum, transparent
yet firm, closes the door against intrusion, and falls back
when the twelve or sixteen ciliated tentacles come forth
for food.

CRISEA EBURNEA.

The Ivory-tufted Coralline, common on such sea-weeds
as Delesseria and Dasya, also on the roots of the Lami-
naria which has been thrown by a rough sea upon the
beach. Finely granulated pear-shaped vesicles are often
scattered over its branches ; it is strongly calcareous ; the
cells tubular, with circular apertures looking towards oppo-
site sides.

CRISEA CORNUTA.

The Goat’s-horn Coralline, more rare, and parasitical on
other zoophytes. This is a very minute species, with long
tubular cells, shaped like goat’s horns, and placed one over

177

Objects for the Microscope.

the other. A fine hair-like bristle projects from the side of
each cell, and speckled oval-shaped gemmse are often found
on the branches.

SERIALARIA LENDIGERA.

The Nit Coralline. Large tangled masses of Serialaria
often lie upon the sea-sand after a storm, or come ashore
clinging to the up-torn branches of Halidrys. It looks to
the naked eye but as some knotted thread ; yet even with a
pocket lens we find each knot to be a little pan pipe, with
from eight to twelve polype cells seated side by side on the
fine silken thread which runs on a little space, and again a
small pan pipe or family group makes what is called the
Nit on the coralline.

FRESH-WATER ZOOPHYTES.

POLYZOA.

These objects, accessible wherever there is a quiet, sha-
dowy pond, or a sluggish canal, or a ditch semi-covered by
the road-side, are worthy of close attention ; indeed, the
development of the Statoblast or Gemmae of fresh-water
Polyzoa is too great a pleasure to pass unnoticed.

STATOBLASTS.

Small oval bodies, found floating on the water of ponds
and ditches all through the winter ; they may be mounted
dry, and are useful thus, enabling the young student to
recognise them in the water. They have an oval brown
centre, and a lighter brown reticulated border, more or less
wide, according to the species. One variety is exceeding
beautiful — the Statoblast of Cristatello mucedo — which has
a scalloped edge and hooked spines of crystal, proceeding
in rays from the border, giving it a sun-like appearance.
These bodies are formed in the interior of the parent
zoophyte, growing like buds from the funiculus or small
cord which attaches the stomach to the endocyst or internal
coat of the tunic. They are not true eggs, yet they produce
perfect polypes, and are not expelled from the Polypidom,

178

Objects for the Microscope,

but may be seen in long files within the horny tube of
Plumatella repens (the most abundant species), both during
the life and long after the death of the parent polype.
Probably the shelter is a needful protection against the
hungry minnows or sticklebats ; but when the Polypidom
decays the Statoblasts float freely on the surface of the
water, attach themselves to Lemna and Anacharis, or even
to stones and sticks, until the warmth of a spring morning
quickens them into life.

If kept in a room they develop sooner. As I write in
this month of February, there are several Statoblasts in my
aquarium with a young Plumatella fully formed, sheltered
beneath the open valves, and waving a circlet of white
tentacles, feeding almost incessantly, and with body so
transparent that every part of its internal economy is visible.
The lophophore, or membrane, which bears the tentacles,
can be seen drawn in like the retracted finger of a glove,
the open oesophagus and striated stomach, its muscular
bands across, and longitudinal, the pyloric cavity, the
cardial cavity, and the movement of the intestine, as it
ejects the rejectamenta.

In a further state we should see the ovary and developing
Statoblasts.

THE PLUMATELLA REPENS,

so called from the Latin word signifying plumed and repenst
or creeping, because of its habit of lengthening the small
brown tubes along stones or leaves, or twining round
Lemna. It looks merely like a dead spray of horny sub-
stance when taken out of the water ; but replace it in a
tumbler of its own soft element, and from every spray will
peer forth a multitude of ciliated polypes, like Membrani-
pora, except — and observe this — the tentacula, ranging from
twenty to fifty in number, are not in a starry ray, but in the
form of a double horseshoe, the outer one fan-shaped, and
the inner one likewise, but more compact, only it sometimes
arches over, and the plumed tentacles seem like a feathery
tent protecting the indweller; or, as was really the case,
enclosing hopelessly the caught infusoria whirled by the
outer current into the hungry mouth beneath. When,

Objects for the Microscope. 179

however, a larger species of prey is taken in the net the
result is sometimes inconvenient. A Notommata heedlessly
sailing along I once saw drawn into the horseshoe snare,
and though with strong bounds he dodged the encircling
arms, and evidently went down against his will, yet down
he went, when presently I observed that he recovered heart
within that prison, and began feeding on the smaller fry
that had been swallowed with himself. The next day the
poor Plumatella looked weak, and was evidently ill at ease
with that rampant Notommata within still jerking about
and feeding. The next day the polype was dead. Out of
the perishing body sprang the triumphant infusoria.

Let me urge every one who can do so to obtain either
the Plumatella itself or Statoblasts, and for all such supplies
of vegetable or animal life the student had better go to
King's, 190, Great Portland Road.

PALUDICELLA

is found in still or slowly running water, attached to stones
in dark corners, the cells very much resembling those of
the marine Eucratia chellcita.

LOPHOPUS

has a transparent gelatinous tunic, enclosing several polypes,
and attaches itself to the stems of Lemna Polyrhiza in dark
ponds or ditches.

ALCYONELLA

may be found in sluggish water in dense masses, after
encrusting the branches of trees which dip into the water.

CRISTATELLA MUCEDO.

The large light-loving, beautiful creature, flinging its
broad polypidom over stems of the water-lily, and they
come forth in a watch-glass under the microscope, neither
shrinking from the light, nor frightened at a jog of the
table, a whole army of tented tentacles waving to and fro.
Sometimes this polypidom looks like a little bit of greenish
sponge floating on the water. The Statoblasts are spined
and crystalline ; they very soon develop a polype which
immediately in a new process of generation multiplies by
gemmation.

180

Objects for the Microscope .

CHAPTER IX.

SEA- WEEDS— MARINE ALG^E.

** The gentleness of Heaven is on the sea.

Listen ! the mighty Being is awake,

And doth with his eternal motion make
A sound like thunder — everlastingly.”

Wordsvsorth .

“ The water is calm and still below,

For the winds and waves are absent there,

And the sands are bright as the stars that glow
In the motionless fields of upper air j
There, with its waving blade of green,

The Sea-weed streams through the silent water,
And the crimson leaf of the Dulse is seen
To blush like a banner bathed in slaughter.”

Percival.

These slides of sea-weeds will surely be very popular
objects; the student at the sea-side will refer to them again
and again for the verification of his own specimens, and for
instruction in the varied tissues and parts of fructification.
The student at home and far inland will bend over them in
delight until he hears the booming wave, and feels the spray
of an up-rushing tide — until, on the wide, wild coast, after
a storm, he seems to see the tangled treasures of these
beautiful plants cast up to perish. Or, as slide after slide
is examined and learned, the strong yearning will come for
a wandering by the sea-side — a rest beside a rock-pool. It
the sea-side has ever been a Home — if our childhood’s joy
has been to patter on the sands with naked feet, and chase
the scrambling crab into its cranny — or, later, with eager
hand to gather Zoophyte and Weed, with an understanding
heart and loving eye for the great works of the Almighty,
then these beautiful specimens will come with the power
of association and memory, as well as with their scientific
value.

A slide of that exquisite Ptilota plumosa sent my spirit
far away from the quiet country home. A sound of a

Objects for the Microscope.

181

gushing tide was in mine ears, the vast expanse of a sunlit
sea before mine eyes — my feet were slipping and bounding
from rock to rock, down to the edge of a retreating wave,
a long way from the shadow of the Serk cliffs. Suddenly,
as in a dream, a deep rock-pool lay before me, on the outer
side of which a forest of Laminaria and Chorda-filum was
streaming out into the sea ; all round the interior margin
were thick clusters of olive sea- weeds, and the dense foliage
of Lichinia, Cystoseira , and Furcellaria. Here and there
beautiful tufts of the jointed Catanella, the delicate Cera -
miitm , Laurentia, Flocamium, and in one dark corner some
fronds of the crimson Rhodymenia , whilst in the deepest
shadow grew the purple Chondrus crispus turning green and
olive in the sunny side of the pool. The water was clear
and untroubled, when with little splash a Cabot * darted
across from crevice to cranny beneath a boulder in the
pool ; a Prawn, gracefully poised, and waving its long
feelers, was lurking under the weeds, and a green, greedy
Crab, was watching a purple, passive Mussel gaping in the
warmth and quietude : myriads of living creatures, tiny
Molluscs and Cytheridse, were rejoicing in that little world
— one single tide-pool.

Not to dream on, but to explore deeper still into the
mysteries and beauties of the sea-flowers — as they should
be called— not weeds.

“ Call us not weeds — we are flowers of the sea ;

For lovely, and bright., and gay-tinted are we,

And quite independent of culture or showers ;

Then call us not weeds — we are ocean’s fair flowers.’*

Landesborough.

We must consider steadily their microscopic parts, and
learn their place in creation.

MARINE ALGA!,

or Sea-weeds, are in the ranks of the lower Cryptogam ia :
yet the range is very wide, from the fructification of the
simple Ulva to the highly organized antheridia and anthe-
rozoides of the Fiicns platycarpus.

* The Guernsey name for the Blennius, or Blenny.

182

Objects for the Microscope.

The greatest interest of the Sea-weed slides will be lost
unless we are acquainted with their fructification ; for no
slide is of much value unless it displays either the Tetra -
spores , or Favellce , or Ceramidium , or Sori, or Nemathecia,
or Antlieridia of the various plants.

It is best to look at these preparations first with the
lowest power, a two-inch object glass, which gives a large
clear field, and displays the general form to the greatest
advantage. Then raise the power successively to examine
the fructification, in doing which we may find some beau-
tiful specimens of Diatomacese attached to the Algae. In
looking over a slide of Ptilota I observed a chain of the
frustules of Grammatophora depending from one of the
pinnae, and two or three beautiful Isthmia obliqua entangled
in another part of the frond ; some Licmophora were at-
tached to the stem, and this single slide gave long and
delightful study, with the use of all the powers of the
microscope.

The fructification of Sea-weed, which is the most im-
portant part, can only be understood by having a collection
of about twelve slides, of the following varieties :

Two slides of Ptilota, which will show either an involucre,
containing three spores, or a lacinia, or little leaf, bearing
numerous tetraspores, that is, cases containing four spores
or seeds.

Two of Plocamium, which give branches bearing
tubercles containing tetraspores, or stichidia containing
spores.

One of Polysiphonia gives an example of a Ceramidium ,
an elegant urn-shaped capsule, open at the top, and con-
taining a group of crimson pear-shaped spores.

Two of Odonthalia , which has two kinds of fructification ;
and on the slide should be either capsular fruit, somewhat
like that of Polysiphonia ; or stichidia , long, delicate pod-
like receptacles, enclosing crimson spores in separate cham-
bers or cells.

Two of Callithamnion, which has capsules seated along
its pinnae, or bran chiefs with bi-lobed Favellce.

Phyllophora shows quite a different kind of fructification,

Objects for the Microscope .

183

called nemathecia, or warts, concealed under leafy processes
composed of delicate moniliform or bead-like filaments.

Rhodymenia gives an example of embedded tubercles
containing spores called coccidia.

Nitophylium is spotted with sori, each of which contains
a number of tetraspores.

Polysiphonia fastigiata abounds with antheridia at the
tip of its filaments amongst spiral fibres.

The fructification of the highest order is that of Fucus
serratus and platycarpus , which should be examined fresh
from the plant, and is seen in perfection between the
months of December and April. It has a truly sexual cha-
racter, and as the receptacles of this Fucus contain both
the 11 sperm-cells ” and the “ germ-cells,” it is considered
an hermaphrodite plant.

In the common Fucus vesiculosus (Bladder-wrack) the
receptacles containing antheridia are found on one plant,
and those containing sporangia on a separate individual;
it is best, therefore, to obtain the F. platycarpus or serratus ,
which latter is found abundantly at half-tide, and easily
recognised by the toothed edges of its frond, when both
organs are observable in the same plant.

Choose a mature receptacle, which maybe known by its
discharging little gelatinous masses adhering round its
orifice. Make a section through it, and you will see a
globular cavity lined with filaments, some of which project
through the pore. These filaments are jointed, or rather
are composed of cells containing what are called anther o-
zoides ; these are yellow dots with two long thread-like
appendages, which, when liberated by the breaking of the
cell, have a spontaneous and rapid motion, and they Imme-
diately swarm around the sporangia, and fecundate them.
The sporangia are pear-shaped bodies lying amongst these
filaments near the walls of the cavity, and they are the
parent cells of the germ cells, which produce the spores or
seeds. Each of these sporangia gives forth a cluster of
eight cells, and are therefore also called octospores.

In the hermaphrodite fuci the spores do not leave the
receptacle until after their fecundation ; but in Fucus vesi -

184

Objects for the Microscope.

culosus , which is a dioecious plant, the antherozoides meet
the spores in the water directly after they issue from the
receptacle.

To observe this, take an olive-green receptacle, which is
the female, and set free a few pores in a drop of sea- water
in a shallow cell ; then liberate a few ripe filaments from
an orange-yellow receptacle, which will contain the anthe-
rozoides, and the whole process of fertilisation may be
watched with a power of 250 diameters.

Then, if you further wish to prove the subsequent pro-
cess of germination, a little care and patience will enable
these very spores to grow from the cell of what is called a
“growing slide,” or even in a tumbler of water, taking
precautions to keep the water fresh and still, by drawing it
off with a siphon, and renewing it daily in the same gentle
way.

The fructification of the Rhodospermese, or red sea-
weeds, has not yet been so thoroughly investigated, and
the varied forms of the spore-cases will be the chief beauty
as wrell as value of the following preparations.

CALLITHAMNION.

There are twenty-five species of this plant, and most of
them are common on the shores of Great Britain ; its name
is derived from two Greek words, signifying “ beautiful
little shrub,” and it is very beautiful, with a rosy or brown-
ish-red frond, or rather filament, jointed and branching,
bearing two kinds of fructification :

1. External tetraspores seated upon the branches.

2. Roundish or lobed berry-like receptacles, called
favellse, seated on the main branches, and containing many
spores.

Callithamnion delights in mud-covered rocks. C. roseurn
is found at Torquay ; also C. gracillimum growing along
the mud-covered base of the harbour. In fact, the collector
must often content himself with a handful of mud, showing
merely a few red filaments, and then on washing these
carefully he will find not only one, but perhaps many
species of this lovely Sea-weed.

Objects for the Microscope.

185

CEKAMIUM.

Fourteen species are on the list of British Algse.

The filaments are of varied colour, from red and purple
to white, jointed and dichotomous, which means regularly
and repeatedly cleft ; it has two kinds of fructification —

1. Capsules, with a membranous pericarp or outer skin,
containing numerous angular seeds.

2. Oblong granules partly imbedded in the joints of the
filaments called favellae.

The name is from a Greek word signifying “ little
pitcher ,” which the capsules nevertheless do not resemble.

Ceramium botrycarpum is found in fruit from August to
November, with clusters of favellse on all the branches —
most beautiful. Its chief habitat is Torquay and Bristol.

Ceramium rubrum is common everywhere in tide -pools
between water-mark.

PTILOTA PLUMOSA.

This lovely little plant, rightly named Ptilota, from a
Greek word signifying u pinnated f from its innumerable
small branches or pinnae, is one of our best preparations ;
for, even without the fruit, its cellular tissue being very
transparent, the cells containing the crimson endochrome
are distinctly seen, and render it a favourite object. The
stem is closely branched right and left with branchlets called
pinnae , and these again cut into exceedingly fine divisions
called pinnuloe ; at the tip of the latter we find the fructi-
fication. This consists of two or three minute capsules
called favellae , each of which contains three or four oval
seeds, and they are themselves surrounded and apparently
protected by several linear segments bending over them.

When fresh gathered for observation, these favellce are
of a rich crimson with a pellucid border, and, seated in their
little cage of crimson pinnulse, are really beautiful.

Another kind of fructification is found on Ptilotse, but
on distinct individuals ; the pinnulse are broader at the tips.,
and covered with oval bodies called tetraspores, from their
containing four seeds.

12

186

Objects for the Microscope.

Ptilota is a perennial plant found in summer and autumn
frequently growing on the stems of Laminaria digitata , and
therefore our best specimens may be gathered on the beach
after the autumnal equinoctial gales. At Torquay it is
found on rocks, but Ptilota sericea is often mistaken for it ;
this is very abundant on the rocks at Moulin Huet in
Guernsey, hanging in rich silky masses on the sheltered
side of the rocks, and thronged with that minute but lovely
zoophyte Eucratia chelata.

PLOCAMIUM VULGARE, OR COCCINEUM.

Plocamium coccineum it is called from its fine crimson
colour, and the word Plocamium means, in Greek, “braided
hair,” which the fine divisions of the frond resemble.

A small branch of this lovely weed has been thus hap-
pily described in a French botanical work, and will direct
the eye in examining this slide. I shall therefore tran-
scribe it : —

“ Sa tige est tres-rameuse, et toujours dans le meme
plan ; Fordre des ramifications est tres-remarquable ; chaque
rameau est legerement flexueux, et rPemet de ramifications
que du cote convexe : la premi&re e st un filet simple et
pointu ; la deuxibmc est un filet qui a trois dents du cote
anterieur ; la troisieme est un filet qui a deux dents, et qui
au lieu de la troisieme dent pousse un filet muni d’une dent
en dehors ; la quatrieme est un filet qui n’a qu’une dent, la
deuxi&me dent est devenue une filet a une dent, et la
troisieme un filet rameux.

“ Apr&s ces quatre ramifications il y a une espace vide,
et la tige emet des rameux semblables du cote oppose.”

The fructification is of two kinds : —

1 . The stichidia, or oblong vesicles containing spores in
separate divisions or cells — very beautiful.

2. Spherical capsules, seated upon the branches, contain-
ing a cluster of spores.

This is a common Sea- weed everywhere in summer and
autumn.

POLYSIPHONIA.

There are twenty-four species of this Sea-weed, some of

Objects for the Microscope. 187

them inhabitants of the rock-pool, some of the wide wild
ocean, growing on the stems of Laminaria, and therefore
often found upon the beach after a storm, or obtained by
dredging on all the British coasts. It also loves to grow
upon Melobesia on the steep sides of rock-pools.

Of all these the P. urceolata and P. elongella are the
best for microscopic observation. The former has a beau-
tiful fructification ; an urn-shaped capsule called a cerami-
dium, furnished with a pore or opening like the mouth of a
vase, and containing a tuft of pear-shaped spores.

A second form of fruit is met with on the same plant —
the tip of a branch expands, and a row of tetraspores is
imbedded in it ; also on Polysiphonia fastigiata such an
abundance of antheridia is found as to give a yellow colour
to the plant, quite visible to the naked eye, and deserving
particular microscopic observation.

SPHERQCOCCUS.

A common plant, often cast ashore after a gale, and
found all along the coast of Cornwall and Devonshire, Isle
of Wight, and the Channel Islands.

It is difficult to obtain perfect specimens of the beautiful
fructification, they are so often destroyed by the violence of
the waves ; but a careful dissection of it fleshly gathered
wrould be both delightful and instructive.

We find minute spherical capsules supported on slender
stalks and mucronate, that is having a little spine obliquely
projecting from their apex ; upon opening this, by making
a section through it, we see a cluster of crimson seeds, also
stalked. The structure of the branches should be noticed ;
they are obscurely but perfectly veined, a faint narrow
mid-rib and lateral parallel veins may be distinctly seen.

GRIFFITHSIA,

so named in honour of Mrs. Griffiths of Torquay, found on
the coast of Devonshire, and other parts of the southern
coast of England. The frond is rose-red, filamentous, and
jointed. The fructification is of two kinds : —

1. Tetraspores affixed to whorled involucral ramuli or
small branches.

188

Objects for the Microscope .

2. Favellse, or gelatinous receptacles, surrounded by an
involucre, and containing a mass of minute angular spores.

There is a beautiful species, called Griffithsia coralince ,
the filaments of which resemble a string of fine glossy
crimson beads, found on rocks at low- water mark, or in
deep pools during summer. This should be mounted, if
possible, with its tetraspores.

GRACILLARIA,

one of the Sphserococcoidse, named from a Latin word
signifying “ slender.”

Gracillaria erecta is found on sand-covered rocks, at
Sidmouth and Torquay ; it fruits in winter,* when it should
be gathered and mounted ; for both kinds of fructification
are beautiful, especially the coccidia, of which sections
should be made to show the spores imbedded in the outer
skin, and the delicate hexagonal cells of the interior.

The coccidia are pod-like receptacles at the tips of the
filaments, and, when magnified, appear to be dotted with
crimson spots. Make a transverse section to observe the
position of the spores. The other kind of fructification is
a frond covered with sessile capsules, about the size of a
poppy-seed, containing a cluster of oblong red seeds.

Gracillaria compressa is sometimes cast ashore attached
to coral and algae at Sidmouth, where it was found by
Mrs. Griffiths, and also in the Channel Islands by other
collectors. It is not generally known that the Island of
Alderney is famous for its rare and beautiful Sea-weeds,
many of them made known by Mrs. Gaudion, wife of the
late judge of Alderney, an indefatigable collector and
admirable preserver of Sea- weeds, to whom I am greatly
obliged for some excellent specimens.

LAURENSIA.

There are several species of this abundant and pretty
Sea-weed. It varies much in colour and size ; some species,
L. pinnatifda, being of a dark purple and even olive colour,
whilst the Laurentia obtusa has a fine pink colour ; though

February and March.

Objects for the Microscope.

189

in rock pools much exposed to the sun it hangs in dirty
yellow bunches, and for that reason is often unrecognised.
The rare Laurentia tenuissima is found plentifully in the
Channel Islands.

The fructification of Laurentia is both various and
remarkable, requiring microscopic investigation.

1. It has broadly ovate capsules, about the size of a
poppy-seed, containing red, pear-shaped seeds, supported
upon narrow stalks. A section must be made through the
capsule to show them well.

2. Ternate granules imbedded in the ramuli, or tips of
the short branches. Simply magnified they appear to be
dotted. A transverse section should be made.

Then, again, on some specimens of the same plant may
frequently be found swollen tips, forming large spurious
capsules, and these are very curious. Some of them have
only a minute pore ; others are spread out more like the
shield of a Lichen, and edged with pink. On making a
section through these, numerous transparent linear bodies
are seen pressed closely together ; they are composed of
minute filaments surrounding a slight column, and termi-
nate in several round pellucid lobes. In the round capsules
they are also present, and by a gentle pressure under the
microscope are seen to issue in numbers from the pore.

Laurentia is found in perfection from June to September.

ODONTHALIA.

This is only found on the Northern coasts of England,
Yorkshire, and Scotland. It comes on shore from the deep
sea finely dotted with fruit in the month of November.
The beautiful stichidia , reddish purple, and the ceramidium
— both kinds are on this plant.

BONNEMAISONNIA,

named after Bonnemaison, a celebrated French Algologist.
Nothing can be more graceful and beautiful than this
exquisite little plant ; the fronds so delicately ciliated, of
a bright rose colour, and dotted all along with tiny cap-
sules— the true ceramidium; each urn-like vase containing

190

Objects for the Microscope.

a group of stalked spore-cases, in which are numerous seeds.
The texture of the plant also is a beautiful microscopic
object. It is found from June to September all round the
English and Scottish coast.

DELESSERIA

is only microscopic in its fructification, and as an example
of Sori. It has two kinds of fructification : —

1. Capsules containing spores, and these are always
found upon the mid-rib and stem of the plant.

2. Sori, or masses of granules collected into little spots
or lines in the substance of the frond, or in little leaflets or
distinct pod-like, leafy processes, which form a sort of fringe
on the mid-rib and margin of the plant. We never find
more than one kind of fruit on any individual.

Delesseria is a well-known and abundant Sea-weed, a
favourite in all collections, from its beautiful colour and
broad fronds.

Delesseria limosa is found after storms attached to the
stems of Laminaria digitata. Specimens have been gathered
in which the frond measured four inches across.

There is one species, Delesseria ruscifolia, which deserves
microscopic attention from its substance between the mid-rib
and margin being transversed by white pellucid branched
veins composed of a single row of elongate cellules. The
colour is a fine rose-pink ; it is found from May to Septem-
ber at Yarmouth, Torquay, Bognor, Ilfracombe, &c.

RHODOMELA.

This is a large, bushy plant, beautifully tufted in the
spring, and bearing feathery tufts of ramuli of light brown-
purplish colour. In early summer, about June, the fruit
is found, and is of two kinds : —

1. Nearly globular capsules, full of free, pear-shaped
seeds.

2. Stichidia, pod-like receptacles, with ternate granules
imbedded in the substance.

Sections of a ripe pod and of the stem are beautiful under
the microscope. The external appearance is as if it were

Objects for the Microscope .

191

ribbed or jointed ; but upon examination we find a tissue of
hexagonal cells, each with a red dot in the centre, and if we
make a longitudinal section we find oblong cells, through
which runs a red filament. It is found upon the drifted
stems of Laminaria and upon rocks in the sea. There are
several species, of which Rhodomela pynastroicfes is the most
common.

SPYRIDIA FILAMENTOSA.

This is rare in England, but found on the coast of Devon-
shire, the Isle of Wight, and the Channel Islands. The
name is derived from a Greek word signifying “ basket ,”
which the receptacles resemble ; for the stalked gelatinous
receptacles have a membranous pericarp often surrounded
by an involucre of short ramuli, containing two or three
masses of roundish granules ; it is these which look like
baskets.

CHAETOSPORA WIGGII

is very beautiful, but rarely obtained in fruit, and has not
yet been thoroughly investigated ; therefore it is mentioned
rather to induce observation when the plant is found in
perfection. It is gathered on the coast of Normandy and
in the Channel Islands ; Sidmouth, Brighton, and Yarmouth
also yield it occasionally. It is of a fine rose colour, and
has very delicate filiform fronds.

HALYMENTA

has a compressed frond, pinky red, consisting of a very
delicate membrane, which when in fruit is dotted with Sori,
and a transverse section should be made, which will show
the spores, called in this plant “ favellidiaf attached to the
inner surface of the membrane. It is found abundantly on
the coast on rocks and stones, in the sea during summer.

DASYA.

There are four species of this lovely Sea-weed. The
name is taken from a Greek word signifying hairy. The
commonest of them, Dasya coccinea , is often mistaken for

192

Objects for the Microscope.

Ptilota plumosa , being found in long crimson feathery
sprays on the coast after storms, or dredged in deep water.
It is a great favourite with collectors of sea-weed for orna-
mental purposes, and is equally valuable for the microscope,
yielding two kinds of fructification ; the Ceramidium, con-
taining pear-shaped spores, and the Stichidia, containing
tetraspores, ranged in transverse bands.

A delicate section of the tower part of the stem will show
the internal structure, which is of numerous parallel tubes
surrounding a central cavity, and edged with a circle of the
short stout hairs which clothe the stem.

Sections of the fruit and of the stem are often indispen-
sable for determining the species, and give innumerable
varieties of beautiful objects.

DASYA ARBUSCULA.

A delicate plant, not uncommon at the verge of low- water-
mark in many parts of Scotland and in the Channel Islands ;
remarkable forits beautiful and abundant stichidia, clustered
amidst the fine ramuli, which cover the frond densely, and
are forked at the tip, jointed, and of a clear crimson-lake
colour, sometimes more or less brown, and always discharg-
ing its fine colour if left in fresh water.

DASYA OCCELLATA

is of a purple colour, and the dense tufts of ramuli at the
tips of the branches give it a dotted appearance, like an
eyelet on each delicate feathery stem. The stichidia are
very long slender pods, full of tetraspores.

DASYA YENUSTA.

A most beautiful and rare little plant, found in the
Channel Islands in summer and autumn. The shape of
the stichidia, which have long acute points, and the re-
peatedly forked ramuli, distinguish it from Dasya arbuscula,
which it otherwise much resembles.

These marine Algse are prepared in Paris, by Bourgogne,
and sold by Baker, of High Holborn. A collection of even

Objects for the Microscope.

193

a few would be most useful to a young student, who thus
might learn what to mount for himself at the sea-side.

As to the method ; when the form only of the plant is
desired I find Canada balsam a good medium. The Sea-
weed being perfectly dry, it only requires placing in warm,
not hot , balsam, and covering with a previously warmed
thin glass cover. But for the display and preservation of
the fructification the following liquid is preferable

goadby’s solution foe marine alg,e.

Four oz. bay-salt, two oz. alum, four grains corrosive
sublimate, two quarts of boiling water.

A cell is to be made on the revolving table with Bruns-
wick black, and thoroughly dried. The specimen then laid
in the cell with enough of the solution to fill the cell, and
the glass cover carefully laid on. Let it stand for a few
minutes, and dry the surrounding glass with blotting paper
before the varnish is applied, which hermetically seals it.
The Sea- weed must be mounted fresh from the sea.

194

Objects for the Microscope .

CHAPTER X.

FORAMINATED SHELLS.

I believe that every one is surprised and delighted with
those lovely little shells ; so minute that they resemble
grains of the finest sand ; and so perfect in structure that
they seem to be the habitation of a more highly organised
animal than they really are.

There are two kinds of foraminated shells, calcareous
and siliceous. The calcareous shells are found alive in
marine deposit, and on sea-weed ; the siliceous are also
dredged up from the depths of the sea, and found in strata
formed of fossil deposits.

The animals which dwell in these beautiful little shells
are of the lowest order in the scale of animal creation, not
yet perfectly understood, and are variously placed by
scientific men. Formerly they were considered as belong-
ing to the family of Cephalopods, or Cuttle-fish. Ehren-
berg, a great naturalist, regarded them as polypes, and
placed them amongst the Bryozoa, or Zoophytes. Du
Jardin, a French naturalist, and most modern authors, agree
in the relationship of foraminifera to those very curious
animals, Amoeba and Actinophrys sol , which are found in
fresh water, and may be studied from our aquariums.

Their internal organization is a simple body of what is
called sarcode, a kind of pulp which has the power of
assimilating and digesting food in all its parts. The body
has no particular mouth, stomach, or intestine, neither has
it eyes or other senses, except feeling ; but it can put
forth long feelers through the perforations in the shell,
and can entangle and draw in its appointed food, which,
whenever it enters, is presently digested, and the residue
ejected, not always out of the shell, for the cavities are
sometimes choked up by these undigested atoms.

Now in some of the Foraminifera the body is single and

195

Objects for the Microscope.

jointed, in others the chambers of the cells are so distinct
that the sarcode body may be considered as compound, and
one tiny shell to contain a family, the members of which
have been produced as gemmae or buds, one from the other.

The subject is still under investigation by scientific men,
therefore 1 shall not enter further into it, but recommend
the student, if desirous of further information, to read
1 Weaver’s Abstract of Foraminifera ’ in ‘ Annals of Nat.
Hist.,’ 1841; ‘Williamson Trans. Micros. Soc.’ vol, ii.,
and ‘ Micr. Journal,’ vol. i. ; also ‘ Carpenter on the
Microscope,’ chap. x.

The structure of the shell itself is various, some being
single-chambered (Iagena, Miliolina, and Gromia) ; the
greater number are compound shells, with cells arranged
lengthwise, or circular, or spiral, all of them dotted with
numerous foramina, or holes, from whence they are named
foraminated shells.

We should have at least three slides of these in our
collection : one of the mixed specimens, one of the beau-
tiful Cristellarea, or Operculina, and one of the siliceous
Foraminifera from the Barbadoes deposit.

THE OPERCULINA

is the best example of a compound shell, to show the divi-
sion into chambers ; it is like a tiny nautilus, and if we
saw the interior we should find each chamber separated
from the other by double walls, or septa, containing tubes,
and which give off lateral branches, and a network of minute
veins for circulation of fluid. A large syphon or tube
forms the margin of the shell, and is the medium of com-
munication between the cells.

The cells of this Foraminifer being calcareous, are easily
dissolved by muriatic acid ; and a recent specimen may be
examined b}^ placing it in a watchglassful of water with one
drop of strong acid, when, in a very short time, the shell
will dissolve, leaving the animal naked and perfect with
every mark of its habitation left upon its plastic body.

On examining a mixed slide you will find that some are
starlike (Astoma), some in complex whorls (Cassidulina),

196

Objects for the Microscope.

some straight and yet chambered (Verneucilina) — the
variety is immense. They are dredged from the depths of
the Mediterranean, the Adriatic and .ZEgean Seas, and on
our own coast they are found also plentifully in the white
drifted sand, or amongst the corrallines in rock pools. The
Oassidulina and Rosalina are the most common in the
Channel Islands. The ouze of oyster-beds also abound
with some species.

FOSSIL FORAMINATED SHELLS FROM BARBADOES.

These are of a different kind ; the shells are siliceous ;
the variety even on this one slide is probably amazing, and
the delicacy of form and workmanship truly worth a long
and careful examination. They were first discovered by
Professor Ehrenberg, at Cuxhaven, on the North Sea, after-
wards found by him in collections made in the Antarctic
Seas. Fancy these fragile and lovely little creatures having
been brought up by the sounding-lead at the depth of 2,000
fathoms ! Such are the beautiful forms which the hand of
God has fashioned in His wisdom, where human eye never
sees and foot of man never treads, and which but for our
microscope, had remained unknown to us as they have been
for the ages past.

Nothing do we examine thus, but it reveals such perfect
finish, such loving design of adaptation to the creature’s
necessities, that we have deeper thoughts than our tongue
can utter, and learn lessons that philosophy has never
taught. Nothing is done carelessly, nothing is isolated or
loose in the scale of creation ; the plan is seen ever wider,
deeper, higher, but complete and in perfect order, whatever
part is presented to our finite mind. We see very little,
we know very little ; but we gaze on, and our hearts are
directed upward even by a slide of microscopic shells
sculptured with hieroglyphics of the Creator.

The Barbadoes deposit alone furnishes 282 varieties ; and
when we consider that in a single ounce of sand 6,000 of
these shells were picked out, and in another ounce from
the shores of the Antilles no less than 3,840,000 were dis-

197

Objects for the Microscope.

covered ; when we learn that these little shells are increasing
so fast as to block up navigable channels, obstruct gulf's,
and fill up harbours, we feel how little we can know of that
Infinite Mind who has so ordered the multiplicity, and so
elaborately worked these foraminated shells.

OKBITOLITES

are circular fossil shells, varying in size from a sixpence to
very minute species, found in all foraminiferous sand. It
is the habitation of a composite animal, often found alive
on sea- weed, but more abundant in the fossil state. The
chambers or cells are arranged in circles — the shell not
sculptured. The animal is of a less high order than the
true Foraminifera. Perforations in the shell are doubtless
for the Pseudopia ; their habits and mode of propagation
are not known.

N UMMULITES.

These are a species of Foraminifera, but only in the fossil
state ; they are much larger, too, varying in size from a
fourpenny-piece to half-a-crown ; they are the habitations
of a composite animal, and the structure of the shell is very
complicate ; the chambers are arranged in spirals round the
centre in great numbers. They abound in the United
States, where a mountain 300 feet high seems to be entirely
formed of these shells. The crystalline marble of the
Pyrenees and the limestone ranges of the Adriatic Sea are
wholly composed of small Nummulites. The Great Pyramid
of Egypt is built upon blocks of limestone consisting of
these foraminated shells — habitations of beings who lived
long before the age of man, and were, amongst others, God’s
instruments for preparing the earth for the perfection of
his creation.

198

Objects for the Microscope .

CHAPTER XI.
SPICULES OF SPONGES.

SPICULES OF SPONGE.

These slides, although useful, and to a certain extent
interesting, are very far from what is wanted to illustrate
the nature of a sponge. They are isolated siliceous spicula
of the horny skeleton of the sponge ; very various in form,
but all for the same purpose of strengthening the framework
of the animal.

Sponges in their living state are by no means like the
dried specimens sold for domestic purposes ; these are but
the dead form, the mere skeleton of what was once a living
creature. When alive it possesses a firm, fleshy substance,
composed of cells about l-7000th of an inch in diameter ;
the horny skeleton is developed in the inter-cellular sub-
stance, and within cells of horny matter these spicula are
secreted.

Sponges present a great variety in their external ap-
pearance ; some being soft as jelly, whilst others are as
hard as flint ; some very large, and others exceedingly
minute. The nature of the body closely resembles that of
the Foraminifera and Amoebse, having no distinct organs,
and capable of assimilating food in all its parts. There is
a current flowing in and out through the whole sponge,
entering the small apertures or oscula, and being expelled
by the animal through the large apertures or oscula. The
channels through which the currents are drawn and expelled
are furnished with ciliated cells, which promote the circula-
tion of the water from whence the sponge derives its needful
supply of oxygen and food for the maintenance of its life.

Objects for the Microscope.

199

This action may be observed by the seaside student on
carefully removing Grantia ciliata , or Halichondria panicece
from its native rock, and placing it in a basin of fresh sea-
water, when they will presently pour forth streams of the
fluid from their oscula, and give full evidence of life.

Their propagation is by gemmation, or by winter-ova,
for a full description of which we must refer to Mr. Bower-
bank’s papers in ‘ Trans. Micro. Soc.,’ 1840, and 'Johnson
on British Sponges/

What we particularly want for an educational box is a
good section of sponge, showing the spicula in situ. The
following slides are, however, very useful, because after
examining the tri-radiate spicula of Grantia, the stellate
pin-shaped spicula of Tethea , the anchor-headed spicula of
Pachymatisma, and the peculiar bi-rotulate spicula of the
fresh-water sponge, Spongilla fluviatilis , we are able to
understand many of the miscellaneous contents of fossil earth
or recent sand, and discern not only the remains of a sponge,
but to what particular family an isolated spiculum belongs.

GEMMULES OF PACHYMATISMA.

These are young sponges or gemmules ; they grow from
the sarcode body, and occur in great numbers towards the
base or root of the sponge; at first they appear as little knobs,
arising from the cellular tissue, their stem lengthens, they
become detached, ciliated, and soon escape from the parent
sponge to whirl for some time in the water, and finally fix
upon their appointed habitat and grow into a sponge.

SPICULES OF GRANTIA NIYEA.

These are tri-radiate spicula of carbonate of lime. With-
out sections of the sponge itself, or engravings, it is not
possible to explain or understand the beautiful arrange-
ment of these spicula for support and for defence ; many of
them project into the cavities of the sponge to prevent the
entrance of foreign bodies, which would assuredly injure
the delicate fibres of its frame.

Granitia compressa is an abundant animal in the caves at
Tenby, and the Gouliot Caves in Serk. Grantia ciliata is

200

Objects for the Microscope .

found in rocky pools hanging like a little bottle with
circle of silvery spiculse round its mouth.

Spicules of Pachymatisma (crutches).
Halichondria incrustans.

„ Griffithsia
Dysidea fragilis.

Tethese.

Spongilse fluviatilis.

Geodia.

Sponge Spicules, Thames.

Serk.

Pin-shaped.

Parallel-spined.
Anchor-shaped.

Truncated.

Clubs.

Stars.

Sponges from the Phillippine Islands.

n ')

n n

17 71

11 11

11 11

11 11

11 11

Objects for the Microscope.

201

CHAPTER XII.

SECTIONS OF BONE.

These are favourite objects for the polariscope, and are
usually selected from their brilliancy under polarized light ;
but the structure of bone is a most interesting study
as connected with comparative anatomy and geological
researches, opening a wide field of observation.

Bone is formed, like all other parts of the body, by the
development of cells, in which secondary deposits of earthy
or inorganic matter consolidate the tissue and form the
substance. Chemically, bone consists of gelatine, with
phosphate of lime, carbonate of magnesia, fluoride of cal-
cium, small quantities of carbonate of lime, and a little
oxide of iron.

The marrow or medullary tissue of bones consists of
ordinary fatty tissue, a particular liquid, and cells, with
vessels and nerves.

The structure will only be understood by the examina-
tion of a few of these slides. Take, for example, a section
of human bone,

man’s metacarpal.

The first thing we notice is the number of apertures
surrounded by laminae or layers of substance in circles.
These are the Haversian canals which serve for the trans-
mission of blood-vessels to the interior of the bone. The
numerous black spots with radiating fibres are called lacunae ,
or bone-cells, and the fine lines are little tubes called
canaliculi , or calcigerous canals. They are dark, because
filled with air, and their shape and size are most important
matters to the naturalist, who thereby can determine to
what class of Bird, Beast, Reptile, or Fish, any given bone
belongs.

Not only so, but by the arrangement of the Haversian
canals and bone-cells, differing in every bone of the body,
from the bones of man to those of the smallest creature,

13

202

Objects for the Microscope .

there is an infinite variety of structure adapted to the
necessities of the animal, more or less of strength, or of
lightness, or of flexibility.

A knowledge of this has enabled Owen, the great osteo-
logist, to ascertain the order and exact position of an ante-
diluvian reptile from a mere fragment of fossil bone.

By microscopic examination of bone the existence of
Reaper reptiles in old red sandstone has been determined,
and the supposed reptile Saurocephalus been removed into
the class of fishes. It is marvellous to observe in the
section of a fossil bone which belonged to an animal of
extinct race, such as the huge Mastodon and Megatherium,
the very same structure and proportionate size of bone-cells
that we find in our domestic animals, and in man himself ;
to compare a section of bone from the colossal Iguanodon
with one from the timid lizard, and find them modelled after
the same type, and by the peculiar form and large size of
the lacunae and canaliculi to recognise the reptile ; or to
examine a section from the fossil bones of the gigantic
Dinornis, whose species has been extinct for ages, and yet
find in the still existing Apteryx a continuance of the race,
and the unmistakable small lacunae of Birds.

It was from a fossil bone of the Dinornis and micro-
scopical examination that Professor Owen ascertained that
it was the femur or thigh-bone of a Bird — that the bird
was large, heavy, sluggish — of the ostrich tribe, and there-
fore probably with the habits of that bird. Afterwards,
when a few more bones were sent to the naturalist, he not
only discovered that they belonged to nine different species,
but was able to determine that one Dinornis was a bird ten
feet six inches high, another nine feet, another five feet, and
so on.

With a very moderate knowledge of the structure of
bone, and a habit of observation and comparison, the student
of geology or of natural history may be able to ascertain
to which class of vertebrate animals any bone, fossil or
recent, belongs. A collection of the jaws and small bones
of Moles, Rabbits, Weasels, and Rats, will give beautiful
preparations. Nor are they difficult to mount ; all we require

Objects for the Microscope.

203

is a small web saw, a good hone, and patience. Slice a
thin bit of bone with the saw, and rub it on the hone with
water until transparent. Towards the end of the operation
fasten the section with balsam to a glass slide, and finish
the grinding carefully, when it may be dried and mounted
like any other object.

The whole jaw of a Mole well ground down is very beau-
tiful, showing the Haversian tubes like a tree branching
out between the fangs of the molar teeth.

Longitudinal sections generally show the structure best.

In the position and use of a bone, the size and number
of the lacunae and Haversian canals are modified to give
the required strength or lightness. The wing-bones of
Birds abound in Haversian canals and lacunae, which give
both elasticity and strength, and there is an interesting
paper on this subject by the Rev. J. B. Dennis, in the
‘ Microscopical Journal ’ for 1843. For the guidance of
the student who may wish to collect specimens and prepare
sections of bone, the following table of the relative size of
bone-cells in Fishes, Reptiles, Birds, and Man, will be
useful : —

Measurement of bone-cells in parts of an English inch.
(transverse sections.)

, r , f one of the largest

\ LonS dlameter I one of the smallest

1 Short diameter j one °l larg®st
v { one ot the smallest

( Long diameter j one °^e largf ‘

1 ” ( one ot the smallest

' j Short diameter ( one °£ ' *e Iarg1ft
bone of the smallest

Turtle j Long diameter { one of the larSest

Human bone

Ostrich

Reptile

Conger Eel

one of the smallest

. 1 Short diameter f one IarSf‘

(.one °f the smallest

f Long diameter { one ,dt!'c IarSf
J & ( one of the smallest

' 1 Short diameter ( one °f largft
bone the smallest

i

1440

1

2400

J_

4000

1

8000

1

1333

1

2250

1

5425

J_

9650

1_

375

1150

1

4506

1

5840

1

550

1135

204

Objects for the Microscope.

See 1 Transactions of the Microscopical Society/ vol. ii.
part ii. p. 46.

The following preparations of bone may be obtained at
Baker’s, and most other opticians : —

Femur of Polioceplmlus
Edwardsi.

Femur of Monkey.
Femur of Eagle.

cD

Bone of Alligator.
Bone of Turtle.

Rib of Python.

Rib of Tortoise.
Horn of Rhinoceros.
Seal bone.

Bone of Antelope.

FIN-BONE OF LEPIDOSTEOS.

A genus of fishes belonging to the family of Clupeidse,
natives of tropical America. They are remarkable for their
long rasp-like teeth, and the hard scales like stone. They
are, with the genus Polypterus, the only living representa-
tives of the vast numbers of extinct voracious fishes whose
remains are found in various secondary formations.

FEMUR OF TETRAO UROGALLTJS.

Tetrao urogallus, one of the Grouse tribe, an. English
species of bird called Cock of the Wood.

SECTIONS OF TEETH.

These are brilliant polariscope objects, and offer the
same interesting subjects for observation and comparison
in various animals, fish, reptiles, and mammalia.

The teeth of Mammalia consist of a crown, or that por-
tion above the jaw-bone and gum ; and a neck, or narrower
intermediate portion.

The substance of human teeth consists of three parts :
the ivory , or dentine , which is white, and of a silky appear-
ance, composed of numerous tubes or canaliculi, called
ivory tubes ; the cement , or bony portion, which forms the
outer coating of the fangs, and is like other bone with
lacunse, but rarely with any Haversian canals ; the enamely

Objects for the Microscope.

205

which covers the ivory, and is extremely hard, brittle, and
fibrous. The fibres of enamel, separated by muriatic acid,
are found to be six-sided prisms, about l-6000th in breadth,
and transversely striped, which are well seen under the
polariseope.

SECTION OF HUMAN TOOTH,

(Perpendicular,)

will show the enamel on the crown, like a narrow border
running round ; the ivory in a broad band round the pulp-
cavity ; and the cement round the fang, dotted with lacunae.

SECTION OF HUMAN TOOTH,
(Transverse,)

will only show the enamel and the ivory.

Tooth of Saw-fish.

Sperm Whale.

Jaw of Myliobates, or Eagle
Ray -fish.

Wolf-fish.

Elephant’s Tooth.
Tusk of Sus Indicus.

206

Objects for the Microscope .

CHAPTER XIII.

HAIRS.

HUMAN HAIE.

The interest of these slides is greatly increased by view-
ing them with polarized light, as they give beautiful colours
over the selenite stage. But, besides the mere play of
colour, it is worthy of observation that the hairs of animals
and insects are so variously fashioned and so delicately
finished, that each species has in some cases a distinct form,
though to unassisted eyes they are perfectly alike. The
structure of hair is cellular, like every other part of the
body, and if it is soaked in acetic acid, or soda, that appa-
rent tube is found to be made up of scales outwardly, pig-
ment cells, linear cells, and nucleated cells within; growing
from the skin in which it is planted, having a bulb-like
root, nourished by ducts and follicles, or small pouches on
either side of the hair-bulb.

When a human hair is young and healthy, it has abun-
dant pigment cells, and therefore is coloured; but, when
old or diseased, either the pigment cells become empty, or
only filled with air, or it is preyed upon by fungi, several
species of which infect the human hair.

HAIES OF DOEMOUSE AND COMMON MOUSE

show a beautiful arrangement of air-cells, and if soaked in
potash these become more visible, with the medullary cells
in two rows.

HAIE OF MOLE.

The cells in the medulla very distinct.

HAIES OF BATS.

These are very remarkable, that of the Indian Bat pre-
senting whorls of scales at regular intervals along the shaft;
others give variety in the medullary structure.

HAIE OF ELEPHANT.

This is a transverse section, showing groups of empty
cells here and there, and others in dense clusters contain-
ing pigment. Examine with polarized light.

Objects for the Microscope.

207

HAIR OF CAMEL.

More nearly resembling wool, soft and flexible, with dis-
tinct cortical cells, giving it the appearance of being jointed.

HAIR OF REINDEER.

In the Deer there are few cortical cells, but the medul-
lary cells are so developed, that they resemble the cellular
tissue of vegetables.

HAIR OF ORNITHORHYNCHUS.

A whole hair of this curious little animal presents a com-
bination of wool and of hair. The base, which is long and
slender, being quite woolly, and the upper part enlarged
considerably, and showing imbricated scales on the surface.
The Ornithorhynchus is a most singular little animal, about
one foot and a half long, with a head somewhat like a
duck ; a body like a mole, and yet so unlike any other
animal that it was at first disbelieved such a genus existed.
It is a native of New South Wales, and called by the
colonists the Water-mole.

HAIR OF LARVA OF DERMESTES.

This is used as a test object, and, when viewed with a
good clear J-inch object glass, should show the shaft thickly
covered with minute spines or scales, placed on whorls up
to the tip, where the last whorl is composed of broader
hairs or scales, somewhat resembling the petals of a flower,
and each scale terminated by a little knob.

The Dermestes lardarius is a small black beetle, very
destructive to bacon ; it has a broad gray band, spotted
black at the base of the elytra. It belongs to the Penta-
mera, having five joints in the tarsi, and to the Clavicornes,
having clubbed antennae. The larvae are most mischievous
in insect collections. So, also, another of the family An-
threnus , whose hairs are mounted as test objects.

We find the larvae of Anthrenus under the bark of old
elm trees in February ; of light brown colour, with tufts
of long hairs on the three lower joints of the abdomen.
These hairs are wonderfully beautiful. Soak them a few
minutes in turpentine, and mount in balsam.

208

Objects for the Microscope .

CHAPTER XIV.

SPICULES OF HOLOTHUBI2E.

Holotiiuri^: are marine animals nearly related to the
Star-fish and Echini, belonging to the Radiata, but very
unlike them in appearance; they are outwardly like a simple
tough sac, with a plume of delicate feelers or tentacula at
its head. It is divided, like the Sea-urchin, into five parts,
having five avenues of suckers, and the plume, though
more or less plumose, is always a multiple of five.

They glide about in sunny rock-pools, or lie under stones,
and have a curious habit of ejecting all their intestines if
irritated or alarmed, yet live a long time perfectly empty,
and have the power of reproducing their very complicated
internal parts. They possess, though outwardly of such a
simple form, heart, liver, intestines, a wondrous system of
circulation, and are so prolific that an individual has been
known to lay 5,000 eggs in one night.

The spicules we mount for the microscope form a kind
of skeleton, being deeply imbedded in the skin, and their
form varies with the species.

SPICULES OF SYNAPTA.

A species of Holothuria found in the Adriatic Sea ; these
calcareous plates are imbedded in the skin and perforated
each with ten or fifteen holes, in one of which an anchor-
like spine is fitted with a hinge, by which it is erected or
depressed at the will of the animal.

These are best observed with the background illumina-
tion.

SPICULES OF CHIRODOTA.

Another species inhabiting the Mediterranean, and the
plates remarkable for their delicate wheel-like markings.

Objects for the Microscope .

209

CALCAREOUS SPICULES OF DORIS.

The Doris is a soft-bodied animal, often called a sea-
slug ; it is one of the Nudibranch mollusca, having its
breathing organs outside its body, and like a starry plume
on its back. It is often seen gliding about in sunny rock-
pools, or sheltered under loose stones — feeding on sponges,
and also on dead fish. The tongue is very beautiful, and
has been noticed amongst the palates.

CALCAREOUS SKELETON OF DORIS.

The skin appears to be strengthened by these calcareous
spicules as a kind of skeleton, and their position is better
viewed when thus mounted.

The shape of the spicules varies a little with the species.

SPICULES OF GORGONIA.

These slides present a variety of calcareous spicules,
which, when examined with the -J-inch power and dark-
ground illumination, or simply with polarized light, show
curious shapes and beautiful colours. They are found in
the skin of the Gorgonia, and each species has its peculiar
shape and colour.

Gorgonias are zoophytes ; when drawn up from the
ocean, as they live at a great depth, they look like a shrub
or small tree of bright salmon colour ; the branches are
spotted with little depressions, but have no appearance of
life. If, however, it is quickly replaced in sea-water, a
lovely sight is seen — from every dot, on every branch,
comes forth a living creature, flower-like, pearly white, and
spreading forth a circle of delicate pinnae or filaments, edging-
eight petal-like tentaeula. They are feeling for their prey,
and drawing in shoals of marine infusoria, like other
zoophytes. When the animals die, the petals shrink in and
the skin hardens, and these spicules are found in masses
throughout. Some — the Gorgonia cristata — have spicules
shaped like double crosses ; some are of a rich purple ;
others crimson ; others again of golden hue even by natural
transmitted light and with moderate power.

210

Objects for the Microscope.

SPICULES OF ALCTONIUM DIGITATUM.

These are likewise abundant in that polype so common
in some parts of our coast, the caves at Tenby, and the
Gouliot Caves in Serk, or are often washed up on the
sea-shore after a storm. Fishermen call them dead men’s
fingers, and they do look like a large yellow finger or
thumb, tough and ugly, until, as with the Gorgonia, we
replace it in sea-water, when the same kind of beautiful
zoophytes appear from the multitude of little spots which
stud the surface. These spicules give firmness to the skin,
and form a sort of skeleton.

SECTION OF ECHINUS SPINE.

This beautiful purple or golden star, with fretwork and
circles in many varieties, is a section or very thin slice of
one of the spines of the Echinus, Sea-urchin, or Sea-hedge-
hog, as it is sometimes called at the sea-side by fishermen
and boys, who either dredge them up from the depths of
the ocean, on oyster-beds, or find them at low- tide in the
crannies of rocks. There are many species ; some very
large and bristled over with small spines ; some exceeding
small, scarely larger than a marrowfat pea ; others, again,
about the size of a hen’s egg, with fewer but much
longer spines, the Cidaris. The common Echinus has no
less than four thousand spines for its defence, the
structure of each spine presenting these beautiful varia-
tions. The centre is usually occupied by a network,
bounded by a row of what appear to be transparent spaces,
but are really sections of those strengthening pillars
which run up the spine and form the exterior of every
layer. Sometimes these sections of Echinus have annular
bands, dividing a finely reticulated space, and some have
hollow spaces. They should be seen on the dark illumi-
nated ground with the dotted lens, or the parabolic
illuminator, when the effect is quite magical. Also using

Objects for the Microscope. 211

the blue selenite the structure is better seen by polarized
light.

A short account of the animal to which this spine
belongs may be interesting to those who eannot read its
perfect history in the work of Forbes on the Radiata. It
belongs to the same division as the Star-fish, the Holo-
thurise, the Medusae, or Jelly-fish, the Entozoa, Polypes,
and Infusoria, in all of which the external or internal parts
radiate like a star, and which are therefore called the
radiatae. In all these, but especially in the Star-fish and
Sea-urchin, the parts are divided and formed by the number
five in a most remarkable manner, and few things would
afford a pleasanter study than one of these sea-urchins,
easily procured in every fish-market in London, or at the
sea-side. The animal is easily killed in cold fresh water,
and then the spines may be examined, with their curious
ball and socket joint, so firmly fixed, yet so easily bending
on every side at the will of the Echinus, who uses them,
not only for defence, but for burrowing in the sand.
Between the spines are multitudes of minute organs, the
uses of vvhich are as yet unknown, called pedecilarise ; they
are of three kinds, pearly white with dotted and toothed
beaks, and move about when the Echinus is alive, opening
and shutting their trifid beaks as if each had an independent
Hfe.

They are beautiful objects mounted in balsam, and viewed
with a low power. When the spines have been examined
they are easily removed by dipping the shell into boiling
water and brushing them off ; then fresh beauty appears in
the tesselated wall of that wonderful house built up by the
Almighty for the Sea-urchin according to a certain plan,
and with such contrivance for its comfort as it is worth while
to examine quietly. First we notice double rows of very
minute holes, dividing the shell into five divisions ; through
each hole a small sucker protruded by which it walked, or
attached itself to rocks or stones ; 1,860 of these suckers
occupying each two of these pores. The plates between
each double row of pores are studded with the balls which
fitted into the socket of each spine ; these fine plates are

212

Objects for the Microscope .

called ambulacral plates, and are not in one piece ; closely
examined each plate consists of many smaller ones, no less
than 300 of them in those five divisions, and again in the
avenues between the pores there are 300 more. 600 plates,
besides the 4,000 spines and countless pedecilarise in the
outward form of the common Sea-urchin !

The structure of the mouth is one which has long been
the wonder and admiration of naturalists, and was compared
by Aristotle to a lantern without a skin, from whence it
has derived the name of Aristotle’s Lantern. Again we
see the number five , in five jaws, each with a long sharp
tooth converging in the centre, close to the mouth, and the
framework of these jaws consists of five times five pieces,
moved by six times five muscles, working with great power
the jaws of this little animal, who feeds on any dead fish
or flesh it can attain, eating also young crabs with great
greediness, and catching them with the suckers which
surround the mouth. The opposite end of the shell is
occupied by five ovarian plates, in each of which there is
an aperture by which the eggs are excluded ; they are
strengthened by transverse bands inside, and again separated
by five smaller plates which bear each a little red eye.
The internal anatomy I shall not enter upon ; enough is
written here to give much interest to the various sections
of Echinus spines which we purchase as microscopic objects,
and which are sometimes glanced at as very pretty crochet
patterns.

OBJECTS FOR THE POLARISCOPE.

POLARIZED LIGHT.

The possession of a polarizing apparatus with a good
microscope is a source of much gratification even to the
unscientific, inasmuch as common substances are glorified
thereby in a marvellous way. My parish boys declared
they had no notion their cows’ horn was so beautiful, and
some of them wished audibly for a waiscoat like the elytra

Objects for the Microscope .

213

of a Dyticus. However, the effect of polarized light is not
only beautiful to the eye, but of real use to the investigator
of tissues, and in the researches of the pathologist, for by
it, the true structure of organic bodies may often be made
clear, when the ordinary white light has failed to develop it.

Hardly in a concise manner can the question be answered,
which is so often asked, “ Why are these objects so coloured ?”
and, What is polarized light? But I may briefly explain
that rays of light reflected from a body under special con-
ditions, or transmitted through certain transparent crystals,
undergo such change in their properties, that they are no
longer subject to the same effects of reflection and refrac-
tion as before.

The common ray of light may be compared to a glass
rod smooth and white, uniform in texture, whilst the
polarized ray is smooth on one side, rough and dark on
the other.

How it becomes so, requires too long a dissertation on
the laws of light and colour ; but so it is. And when this
polarized ray is either thrown upon or transmitted through
various substances, it is either reflected, or absorbed and
extinguished according to the structure of the object pre-
sented to it. The most brilliant colours are developed by
this process, especially in crystals, feathers, sections of quill,
bone, hoof, horn. A good selection of these objects is of
value to the microscopist.

SELENITE,

which is a mineral substance consisting of crystallized
hydrated sulphate of lime, when split into thin layers or
laminae, are very beautiful under polarized light, and discs
of blue or red selenite are used to enhance the colour of
objects for the polariscope. There are many crystals and
organic substances whose thickness is not suitable for the
production of distinct colour, which, when a plate of selenite
is placed beneath them, exhibit a brilliant array of the most
gorgeous hues. A good disc mounted in brass costs five
shillings, but smaller ones may be obtained at Baker’s for
one shilling, and answer every purpose.

214

Objects for the Microscope.

RHINOCEROS HORN.

A section of this beautiful and familiar object is a good
example of the effect of polarized light. By common light
we see a pale yellowish substance composed of horny fibres
interlacing and forming cells of concentric layers round a
minute central point. All this is faintly visible ; but sub-
jected to the action of polarized light, brilliant bands of
gold mark out the compartments, whilst the layers of blue,
purple, or green, circle round a spot which probably cor-
responds to the papillae of the cutis.

WHALEBONE.

A longitudinal section exhibits the laminae of compressed
cells on either side of the medullary cells, varied and beau-
tiful in colour. The transverse section shows the large
concentric cells and pigment granules yet more vividly
bright.

ELYTRA OF DYTICUS.

This exquisite preparation for the polariscope requires
considerable time and care to give it the necessary trans-
parency, for the exhibition of colour entirely depends upon
the preparation.

The elytra is naturally hard, black, ribbed, and dotted ;
the structure scarcely visible. It must be soaked in potash
for a month, then examined, washed, dried, soaked in tur-
pentine, and finally mounted in balsam ; when nothing but
the suckers of that same beetle can exceed it in colour.
The richness of the golden ground, the blue and crimson
spots on which the black cross of polarized light is seen,
makes it a truly glorious object.

Hairs from the leaf of a fern show like glittering stars in
the dark blue, midnight sky.

THE CUTICLE OF DEUTZIA LEAF

shows the stellate siliceous hairs of all colours on the cel-
lular tissue.

Objects for the Microscope .
SECTIONS OF QUARTZ

give infinite variety and arrangement of colour.

The following list of objects is specially for the polar-
iscope, and may be obtained at Baker’s and at other opti-
cians : —

Sections of bone.

Hairs of animals.

Hairs from plants.

Fibres of Palm.

Section of Vegetable Ivory.

Papyrus.

Palates of Whelk.

Sections of Marble.

„ Granite.

„ Agate.

Foot of Wasp.

Elytra of Beetle.

Section of Cuttle-fish bone.

Crystals of Borax.

Salicine.

Cellularia (Zoophyte).

Gemellaria (Zoophyte).

Sections of Infant Skull.

Section of Tooth.

Crystals of Iodo-disulphate of Quinine,

Oxalate of Ammonia.

216

Objects for the Microscope 4

CHAPTER XV.

ANATOMICAL INJECTED PREPARATIONS.

These beautiful and instructive preparations will be
found most suitable objects for examination with a binocular
microscope ; and as this little hand-book is intended for the
non-medical and young students of Natural History, a
description of the usual preparations shall be as brief and
clear as possible.

If the structure of a Bee’s tongue, or of a Cricket’s
gizzard, be interesting to us, and the spiracle of a Beetle
and egg of a Fly be worthy of a place in our cabinet, much
more so must be those organs of our own life upon which
our health of body or of mind depends, and which in their
elaborate workmanship and forethought prove how fearfully
and wonderfully we are made. It is not a merely curious
study, for if we did understand the mechanism of our body
better we should not so recklessly peril its safety, by the
careless folly of fashion or the unbridling of our passions.

INJECTED PREPARATIONS
Of Human Liver — Rabbit — Pig — Monkey, &c.

These are either injected with chromate of lead, Ver-
million, or, if for transparent injections, with Prussian blue
and carmine. The sections give the lobular and inter-
lobular vessels, sometimes the blood-vessels only, or the
interweaving capillaries and hepatic vessels in different
colours.

The preparation before me of Sheep’s liver is one of
Topping’s, presenting a beautiful series of radiating, minute
vessels, in a mingled network of blue and carmine ; the
stereoscopic effect detaches every capillary, and we look
through the delicate structure.

Objects for the Microscope.

217

To appreciate this preparation we must understand the
action and office of the Liver,

This organ is employed in abstracting from the blood
that secretion called Bile, which is necessary to complete
the process of digestion, though its precise mode of acting
is still unknown. The liver is situated at the right side of
the stomach, and at its lower end a large vein, called the
portal vein, enters, charged with blood that it has received
from the intestinal veins, returning with impure blood from
various parts of the body. This portal vein is injected blue ,
and has spread into those innumerable capillaries which
distribute the blood throughout the liver, and in a most
unusual way reunite and coalesce into a large cavity at the
upper end of the liver, called the vena cava. Through
this channel the cleansed blood is propelled into the heart,
to be afterwards sent through the lungs for further
purification.

The substance of the liver itself is made up of secreting
cells and passages, called hepatic ducts (colour injected
with carmine), with branches terminating in enlargements,
called lobes , round which the capillaries spread. The bile
withdrawn is poured forth through a third passage into the
duodenum, or small intestine nearest the stomach. Here it
mingles with the food, performs the office assigned to it,
and the superabundance passes on and away from the
system altogether.

VILLI.

Small Intestines of Man — Monkey — Pig — Dog — Cat — Kabbit.

Any of these will show the structure which absorbs the
nutritive part of our food immediately after its leaving the
stomach. We see in this preparation a crowd of papillse,
covered with a network of vessels injected either with Vermil-
lion or chromate of lead. These are the villi, or minute pro-
cesses of the mucous membrane of the small intestines; two
or more arteries are distributed to each villus, and from
their capillaries proceed one, two, or more veins, which pass
out at the base of each villus. Also there are one or more
lacteal vessels in each of these minute villi, spreading in a

14

218

Objects for the Microscope .

network over the surface, interwoven with the capillaries
and absorbing the fatty part of our food, whilst the blood-
vessels absorb the dissolved part of any kind. The villi
are closely crowded in the small intestines, preventing the
too quick passage of the food, which here receives the
needful bile from the liver and pancreatic fluid.

A transverse section of

DUODENUM OF MOUSE

gives a transparent view of the villi, in which both blood-
vessels and lacteals are distinctly visible.

TIIE LUNG.

Human-—- Monkey — Bear — Puppy — Pig — Cat — Sheep — Fowl — Goose —
Turtle — Rattlesnake — Frog — Tortoise.

The usual sections of lungs of animals present the capil-
laries of the veins charged with impure blood, woven in
close network around these bronchial tubes, which aerate
the life-blood, and send it back pure and bright into the
heart, to leap forth again throughout the whole living
frame. The air we breathe is composed in every one hun-
dred volumes of seventy-nine volumes of oxygen. It is
the oxygen that gives life and is the essential agent, the
nitrogen merely modifies its too energetic action, and when
this gas comes into contact with the carbon contained in the
blood of these fine capillaries, carbonic acid, deleterious
and noisome, is the result, and we breathe it forth at every
expiration. Then the sluggish purple blood brightens, and
in vermillion streams flows on in a web of capillaries, which,
if those of the lungs only were extended, would cover a
space of 2,642 square feet, and the air-cells themselves
number 600,000,000. This lung in a single year will have
contracted and dilated 9,000,000 times, will have inhaled
100,000 cubic feet of air, and aerated more than 3,500 tons
of our life-blood.

If, however, we are looking at slides of other than human
lungs — the reptile, or the bird — we shall see modifications
wisely arranged for the habits of the creature. In th*
lung of the Fowl or Pheasant, an immense number of

Objects for the Microscope.

219

capillaries are exposed to the air by means of lobules or
lunglets, each of which has its own bronchial tube and
system of blood-vessels. Each lobule has a central cavity
surrounded by a solid plexus of blood-vessels, which is not
covered by any limiting membrane, but admits the air freely
between the meshes.

In the lungs of Reptiles the respiratory surface is formed
by the walls of an individual internal cavity, with thin
membranous wall, and simple, smooth expanse, except at
the upper end, where the tracheal vessels enter, close
covered with a network of capillaries, and these ramify over
the surface, depressing it into sacculi or air-cells, each of
which has a capillary network of its OAvn, very considerably
increasing the surface of blood-vessels exposed thus to the air.

THE GILL OF AN EEL

will present a beautiful object, and show how this external
lung is adapted for life in another element than pure air.
The laminae are divided into minute leaflets, over each of
which the finest possible web of capillaries is traced, and
the strength of the muscular apparatus connected with each
arch of laminae renews the fluid necessary for their perfect
aeration, without the cilia, which is needful in the gills of
Oysters, Mussels, and Molluscs, also in the temporary gills
of the young Water-newt.

THE INJECTED FIN OF A TURTLE

is an exquisite object, showing the blood-vessels like coral-
branches gleaming in the water depths, less numerous, and
therefore more distinct in form, than in most circulatory
preparations.

THE STOMACH OF A MOUSE.

This is the best object for examination of and under-
standing the structure of the stomach, as the section gives
a transparent view of the gastric vessels, and also of the
pyloric opening.

The animal stomach is a strong muscular sac, consisting
of three separate layers or sets of fibres, which give it the
power of contraction and dilatation. It is lined with a
mucous membrane, smooth and velvety when distended,

220 Objects for the Microscope.

but loose and plaited when contracted. The internal sur-
face is somewhat like honeycomb, with shallow cells, at the
bottom of which lie the minute orifices of the gastric glands.
We see these glands looking somewhat like villi in the
injected preparation, but they are essentially different both
in structure and office. These tubular glands produce the
cells containing the gastric juice which digests our food.
When the stomach is empty they are at rest and the orifice
of each is closed, but no sooner does food enter the stomach
than the capillaries surrounding each gland become excited,
and the glands commence actively secreting an acid fluid,
which oozes in minute drops from their open mouths and
mixes with the contents of the stomach.

The pyloric opening is the passage into the duodenum ;
during the first part of digestion it is completely closed,
but as digestion progresses it relaxes more and more,
suffering even undigested portions to go through it.

THE SKIN.

Injected portions of the skin usually show the fibro-
cellular tissue called the corium, elastic, yet dense and
tough, beneath which lie the important sweat-glands, the
hair-follicles, and the papillae. The web that we see is com-
posed of fat-cells, blood-vessels, absorbents, and unstriated
muscular fibre.

SECTION OF PALM OF THE HAND OR FOOT OF CAT— DOG —
MONKEY.

This will show the cutis above and the papillae beneath,
forked or trifid with loops of capillary blood-vessels. The
papillae are not all furnished with nerve-fibres; many of them
have merely blood-vessels for the supply of the epidermis,
and those which possess nerve-fibres are usually destitute
of blood-vessels. The sensory papillae contain a peculiar
“ axile body,” or bundle of fibrous tissue, upon which the
nerve-fibre terminates.

If you do not mind snipping a papilla from your own
-'ongue with a sharp pair of curved scissors and soaking it
in a solution of soda for a few minutes, it becomes trans-
parent, and the nerve-fibres are distinctly seen. In some

Objects for the Microscope.

221

sections of the skin, hair-follicles are visible, and the
foot of the Cat exhibits these. In other preparations the
sweat-glands are shown, which are long tubes coiled into a
knot near the closed end, and a straight or spiral duct
piercing the skin at the surface between the papillae. These
glands are most numerous as well as large in the palm of
the hand — there are 2,736 in each superficial square inch ;
upwards of two millions in the whole body, carrying off car-
bonic acid and water, as well as various other Substances
superabundant in the system — chloride of sodium, muriate
of ammonia, phosphate of soda, lactic acid, and carbonate
of lime.

The lower animals, more particularly the naked Amphibia,
as Frogs and Toads, exhale carbonic acid gas most abundantly
by the skin, and respire also, absorbing water as well as air,
by means of the sudoriparous glands.

THE SKIN OF THE TOAD

is very interesting, for it shows not only the network of the
capillaries, but the pigment-cells beneath.

CILIARY PROCESSES.

THE EYE OF THE OX.

This is a magnificent object, exhibiting the blood-vessels
of the choroid membrane and ciliary processes.

THE EAR OF A MOUSE.

A really beautiful preparation, showing the cartilage-cells
and the structure of the mouse’s hair, also the injected
arteries and veins. The cartilage-cells are simple in this
part of the body, resembling the parenchyma of vegetables,
and the substance is without blood-vessels, being nourished
by those which spread over them in the enveloping mem-
brane of the ear.

They are the lowest order of animal cells, like the Algae
of the vegetable kingdom, without vessels of any kind, and
nourished by inhibition.

THE TOE OF THE WHITE MOUSE.

A very popular object, and worthily so. If the section

222

Objects for the Microscope.

is thin, transparent and perfect, it will show the structure
and position of the nail, the corium and papillae beneath ;
the joints and shaft of each bone of the toe, with its attendant
arteries and returning veins ; also the hairs, with bulb and
follicle to each. In these hairs the outer cortical or invest-
ing membrane is distinctly seen, banded or crossed in the
centre with a double row of medullary cells. When these
last two slides have been looked at with a low power,
examine further with a half-inch.

INJECTED PREPARATIONS.

THE KIDNEY.

The Rabbit or the Cat gives an excellent preparation of
this organ.

The whole substance of the kidney is made up of urinary
tubules, with attendant arteries and veins. These tubes or
passages are lined with cells like paving-stones, called
“ epithelial cells,” and those round bodies injected blue or
crimson are the Malpighian tufts, or terminations of a
tubule, into which an artery runs and twists about, forming
a plexus of minute blood-vessels, ultimately uniting to a
single outgoing or efferent vessel, which branches off again
into a capillary network, situated in the cortical or outer
substance of the kidney. These solitary efferent vessels are
like the portal-vein system of the liver, both serving to
convey blood between two capillary systems. The inter-
stices between the blood-vessels, nerves, and tubules of the
kidney are occupied by areolar tissue.

TONGUE.

Human — Monkey — Dog — Cat — Mouse.

If a perpendicular section of the human tongue be
obtained, we shall see that it consists of a free surface,
covered with structures analogous to those of the skin, a
cutis or corium , on which are placed papillce , which are
more developed in the rough tongue of the Dog and the
Cat than in the human subject ; consequently an injection
of the dog’s tongue is a more beautiful object. The fungi-

223

Objects jor the Microscope.

form papillae spread out in looped capillaries, whilst on the
surface beneath is seen an intermediate plexus of minute
vessels. The artery and its vein are distinctly visible in
each papilla, with the attendant nerve.

THE BRAIN.

Cat — Rabbit — Mouse, &c. &c.

OR, SECTIONS OF SPINAL CORD OR GANGLIA.

We touch any slide of Brain reverently, for we stand
here upon the border-land between the visible and the
invisible, the known and the unknown, whether it be of
animal instinct or human reason, whose seat lies here.

Beautiful are these delicate capillaries, spreading round
and over each convolution of the brain ; strange are these
stellate forms of nerve corpuscles imbedded in a dimly-
shaded or granular substance. Nerve fibres ramify and
interlace — nerve force flies along each fibre with immea-
surable velocity. We know that, chained within this
complex nerve system, the living soul goes to and fro in
contact with the outer world, upon the countless paths
which issue from the twelve pair of cerebral nerves and
thirty-one spinal nerves ; each of these has a double fibre
of sensation and of motion ; they are separate, yet sheathed
together ; if we cut one of them the power of movement is
gone, whilst sensation remains ; if we cut the other, then
convulsive, irregular movement stirs a limb which can no
longer feel. We know that, flashing from the invisible
dweller within that little brain, instinct or intelligence
governs the whole of this material frame. We have learned
works on the phenomena of motion or the physiology of the
nerves, theories plausible and wild concerning this organ
of the mind, and we feel keenly how very slight a jar may
trouble for ever the right action of the intellect ; but we
really have little knowledge beyond the mere structure of
the Brain, and we gaze wistfully, it may be, at the most
difficult of all preparations to prepare satisfactorily.

All these preparations may be procured at Baker’s, from
fifteen pence to two shillings each.

224

Objects for the Microscope.

CHAPTER XVI.

SLIDES OF CRYSTALLIZATION.

These are beautiful polariscope objects, and extremely
useful to the young student as first lessons in crystallo-
graphy, and incentives to experimental knowledge of the
various forms of mineral substances. Crystals are con-
stantly met with in the examination of both animal and
vegetable tissues ; it is therefore necessary to become
acquainted with the most common forms, if we use our
microscope understandingly.

In the cuticle of onion we find crystallized oxalate of
lime ; in rhubarb also, but varied in form, as it is combined
with tartaric, citric, or malic acid. Every crystallizable
mineral substance has a definite form of crystallization, and
often many accidental or secondary forms. Carbonate of
lime — a substance well known as forming chalk, marble, &c.,
and abundant in animal structure— is found in hundreds of
secondary forms ; in groups of radiating needles, in hexa-
gons, in rhombohedral forms, as in the shell of the Oyster;
thus the perfect knowledge of the laws and accidents of
crystallization is a deep study ; in fact, it is to mineralogy
what mathematics is to common arithmetic, and cannot be
entered upon in a mere catalogue of slides.

The following preparations are recommended for beauty
and utility, when examined with polarized light ; a plate of
selenite is frequently indispensable for the display of colour
and accurate observation of outline.

SELENITE

is itself a form of crystallization ; native crystallized hy-
drated sulphate of lime, called also satin gypsum or quarry-
glass. It is found in the quarries on Shotover Hill, Oxford ;
but the finest crystals are met with at Montmartre, near
Paris.

The primary form is that of an oblique rectangular
prism, with ten rhomboidal faces, two of which are larger
than the rest.

225

Objects for the Microscope .

It is split into thin laminae, and mounted on glass slides
for the polariscope, and upon the thickness of the film
•depends the colour.

The following list of crystals may direct the student to
many interesting specimens : — *

Acetate of Copper.

Acetate of Manganese.
Acetate of Soda.

Acetate of Zinc.

Acetate of Lead.

Agate, transparent sections.
Alum.

Arseniate of Potass.
Bicarbonate of Potassium.
Bichromate of Potassium.
Borax, or Birate of Soda.
Boracic Acid.

Bismuth.

Carbonate of Potass.
Carbonate of Lime.
Carbonate of Soda.

Chlorate of Potass.

Chloride of Barium.
Chloride of Cobalt.

Chloride of Sodium.

Citric Acid.

Deut-iodide of Mercury.
■Granite, transparent sec-
tions.

LIy dr o chlorate or Muriate of
Ammonia.

Iodide of Potassium.

Iodide of Quinine.

Nitrate of Ammonia.

Nitrate of Baryta.

Nitrate of Bismuth.

Nitrate of Copper.

Nitrate of Soda.

Nitrate of Uranium.

Oxalic Acid.

Oxalate of Lime.

Oxalate of Ammonia.
Oxalate of Potass.

Oxalate of Soda.

Phosphate of Ammonia.
Phosphate of Soda.

Salicine.

Sulphate of Ammonia.
Sulphate of Copper (Blm
Vitriol).

Sulphate of Iron.

Sulphate of Magnesia
(Epsom Salts).

Sulphate of Soda.

Sulphate of Zinc.

Sulphate of Nickel.

Sulphate of Cadmium.
Tartaric Acid.

Uric Acid.

The formation of Crystals under the microscope may be
watched with the greatest facility. A little common salt
(chloride of sodium) dissolved in water, and a drop of the
solution placed on a glass slide gently heated over a spirit
lamp, or by applying the corner of the slide to the candle,

* These are mounted for the Polai'iscope by Mr. Topping.

226

Objects for the Microscope.

will show the formation of crystals in primitive cubes, ter-
minated by quadrangular pyramids. The water slowly
evaporates, and the atoms held in solution return to their
natural form.

ACETATE OF COPPER

is made by dissolving common verdigris in excess of diluted
acetic acid, and when crystallized on the slide will exhibit
the phenomena of dichromism or double colour, deep blue
and yellowish green.

SULPHATE OF COPPER.

Blue vitriol dissolved in water, and likewise treated with
a gentle heat, will show the formation of beautiful blue
crystals in oblique rhomboidal prisms.

ALUM

does not polarize, but gives crystals of the octohedral form.

OXALURATE OF AMMONIA.

This is most beautiful in the formation of its crystals ;
they appear on the slide as circular discs or very flat spheres,
consisting of minute needles radiating from the centre, and
sometimes projecting beyond the circumference of the disc.
Without the selenite stage these discs are like brilliant
little white stars, traversed by a black cross ; with the
selenite they are splendid objects, the colours often disposed
in concentric rings.

MUREXIDE OR PURPURATE OF AMMONIA

is an artificial product of the decomposition of uric acid.
The crystals are flattened, short, four-sided prisms, of bright
ruby red by transmitted common light, and the two broad
surfaces are emerald green by reflected light.

HYDROCHLORATE OR MURIATE OF AMMONIA.

This salt crystallizes in cubes, octohedra, and trapezohedra.
A very little of the powdered salt dissolved upon a slide
and heated gives a beautiful exhibition of feathery crystals
darting across the field of sight, and breaking into stars
and crosses. They do not polarize.

Objects for the Microscope .

227

OXALATE OF AMMONIA.

This is obtained by neutralizing a solution of oxalic acid
with ammonia or its carbonate, and evaporating, which
gives long, slender needles belonging to the right rhombic
prismatic system, and very brilliant crystals under polarized
light.

SALT OF BRUCIA.

Using a solution of ammonia with certain salts will give
an infinite variety of beautiful crystals ; for instance, a
little salt of brucia, diluted and mixed with ammonia, will
produce delicate star-like groups of crystals ; and if a
solution of sulphocyanide of potassium is used instead of
ammonia, the crystals are more feathery, and resemble
sheaves of brilliant little lances.

Solution of hydrochlorate of strychnine with ammonia
gives an immediate precipitate of minute prismatic crystals,
well defined.

A solution of quinine with ammonia gives a perfectly
amorphous precipitate ; with sulphocyanide of potassium it
gives very pretty, irregular groups of circular crystals ; but
it is well to allow twenty-four hours for the formation of
these, as if hurried they are extremely minute, and not so
perfect.

IODO-DISULPHATE OF QUININE.

This is sold prepared for examination ; the crystals
possess a more intense polarizing power than any other
known substance. They are difficult to mount, though the
formation is an interesting process, and may be attempted.
The salt is prepared by dissolving disulphate of quinine in
strong acetic acid, warming the solution, and dropping into
it an alcoholic solution of iodine in small quantities at a
time, and placing the mixture aside for crystallization.
They dissolve in hot alcohol, but are not soluble in cold
alcohol or ether.

To prepare for mounting, a little of the liquid containing
the crystals should be placed on the slide, and the liquid

228

Objects for the Microscope .

removed with blotting paper. When the crystals are dry,
the Canada balsam, previously made thin with ether, may
be applied without heat.

BORAX, OR BI-BORATE OF SODA,

is soluble in twelve times its weight of cold and twice its
weight of boiling water, and crystallizes in very perfect
forms of oblique octohedral prisms. Dissolved in alcohol,
and dropped on a slide, it crystallizes immediately.

BORACIC ACID

is the acid of the salt borax, and is prepared by mixing
three parts of borax dissolved in twelve parts of boiling
water with one part of sulphuric acid.

When a little phosphoric acid is added to the boracic
acid, and the solution dropped upon a slide, then laid upon
a warm iron plate, most beautiful discs are obtained, which
exhibit the cross and coloured rings under polarized light.

From the simple solution of boracic acid we obtain
crystals belonging to the doubly oblique prismatic system,
having two optic axes. Sometimes, when rapidly crystal-
lized, the boracic acid forms arborescent crystals on the slide.

SULPHATE OF MAGNESIA.

(Epsom Salts.)

The solution will deposit crystals belonging to the
rhombic system, and varying in form according to the
treatment in crystallizing. They polarize brilliantly with
the selenite stage.

AMMONIO-PHOSPHATE OF MAGNESIA

is a salt frequently met with in animal secretions which
have undergone decomposition ; they belong to the rhombic
system, but their varieties are endless. Stellate and pen-
niform crystals are frequently found in urine.

URIC ACID, OR LITHIC ACID.

This acid abounds in animal secretions, in the excrement
of birds, serpents, &c., and the urine of mollusca and
carnivorous mammalia. The crystals belong to the right

229

Objects for the Microscope.

rhombic prismatic system, but are various in form and size.
They polarize light splendidly.

NITRATE OF POTASH, NITRE, OR SALTPETRE.

This salt is dimorphous ; it crystallizes in various forms,
but they all belong to the right rhombic prismatic system ;
sometimes six-sided prisms with dihedral summits are on
the slide, and sometimes obtuse rhombohedral crystals,
resembling those of nitrate of soda ; but they all polarize,
and exhibit the phenomena of analytic crystals.

Analytic crystals are those which possess the power of
analyzing light, like the tourmaline used in the ordinary
polariscope.

SALICINE,

an alkaloid extracted from the bark of the willow tree, and
crystallizing in beautiful forms, either in discs exhibiting the
cross and concentric circles of colour, or in prismatic crys-
tals in stellate and irregular groups, polarizing admirably.

NITRATE OF SILVER,

crystallized on a slide, shoots over the glass in most bril
liant feathery crystals, and is also a splendid object viewed
with a spotted lens or parabolic reflector.

I RECOMMEND THE FOLLOWING OBJECTS AS THE CONTENTS

of a good Educational Box :

Cuticles of Lily, Candytuft, and one or two others, tt
show cells and stomata.

Cuticle of Indian Corn, or Equisetum, to show siliceous
cuticle.

Cuticle of Hyacinth, to show raphides.

Cells of spiral fibre.

Scalariform vessels.

Starch grains.

Hairs of Deutzia leaf.

Scales on leaf of Elseagnus or Tillandsia.

230

Objects for the Microscope,

Pollen of Hollyhock or Mallow.

Stamens.

Sections of Wool, Endogens and Exogens.

A capsule of Moss.

Spore-cases of Eern.

Elaters of Equisetum.

Elaters of Jungermannia.

Leaf of Moss or Jungermannia.

Specimens of Eungi.

Mould, Arsyria, Phragmidium, or Puccinea, blight of
Wheat.

Heads of Insects. — Bee, Wasp, Beetle, Butterfly, Hyme-
noptera, Blow-fly, Panorpa, Tipula, to show the tongues and
eyes, and study them comparatively.

Antennae of Syrphus, of Cockchafer.

Leg of Dytiscus, Gyrinus, a Ely, a Beetle, a Saw-fly.
Wing of Wasp, for hamuli ; wing of Syrphus, of Hemip-
tera, of Moth, to show scales.

Spiracles of Dytiscus ; Trachea of ditto, or Silkworm ;
Aerating leaflets of Libellulae, or Ephemera.

Sting of Wasp or Bee, of Gnat, of Horse-fly.

Elytra of Diamond-beetle, of Hemiptera.

Saws of Saw-fly.

Egg of Breeze-fly.

Acarus of Sugar.

Palate of Whelk and Helix, Limpet, Doris.

Zoophytes. — Sertularia, Laomeda, Notamia, Gemellaria,
Cellularia, Elustera, Plumularia.

Sections of Bone and Teeth. — Human bone, reptile bone ;
one of fish, of bird, of quadruped.

Hairs of Animals. — Elephant, Mouse, Bat.

Spicules of a Sponge.

Spicules of Gorgonia and Holothuria.

Section of Echinus spine.

Infusorial Earths, three or four specimens, especially
Discs from Guano and Naviculse.

Sea-weeds, Callithamnion.

Ptilota Poly siphon ia.

Useful Practical Manuals.

PRICE TWO SHILLINGS EACH.

The DESK BOOK of ENGLISH SYNONYMS.

By John Sherer.

A very valuable help to the Art of Composition, as well as
a useful Book of Reference to the Student and the Secretary.
Besides the etymology of words, their general acceptation is
also explained. An Analytical Index, containing the whole
of the Synonyms indicated by the pages where they occur,
arranged in alphabetical order facilitates the search for a
word.

A SHORTHAND DICTIONARY. By J. Dimbleby.

Being a complete Alphabetical Arrangement of All English
Words, written without vowels; adapted to aU systems of
Shorthand. The design of this book is to assist writers of
Shorthand to read what they have written, and to make
the introduction of vowels less necessary by reporters.

The DICTIONARY of BOTANICAL TERMS.

By Rev. J. S. Henslow.

Illustrated by nearly Two Hundred Woodcuts.

The recognised Standard Work on the subject.

GROOMBRIDGE & SONS, 6, Panyer Alley, London.

Useful Practical Manuals.

PRICE TWO SHILLINGS EACH.

PROFITABLE GARDENING. By Shirley Hibbekd.
A Practical Guide to the Culture of Vegetables, Fruits, and
other useful outdoor Garden Products ; intended for the use of
Amateurs, Gentlemen’s Gardeners, Allottees, and Growers for
Market. Illustrated.

THE WINDOW GARDENER. By J. R. Mollison.

Being Practical Directions for the Cultivation of Flowering
and Foliage Plants in Windows and Glazed Cases, and the
Arrangement of Plants and Flowers for the embellishment
of the House.

Illustrated with, numerous Wood Engvavings.

THE FERN GARDEN. By Shirley Hibberd. How

to make, keep, and enjoy it; or Fern Culture made easy.

Illustrated throughout with Wood Engravings.

Contents : Ferns in General — Fern Collecting —How to farm
an outdoor Fernery — Rock Ferns — Marsh Ferns — Ferns in
Pots — The Fern House — Fern Cases — The Art of Multi-
plying Ferns — British Ferns— Greenhouse and Stove Ferns —
Tree Ferns— Fern Allies.

GROOMBRIDGE & SONS, 6, Panyer Alley, London.

b*ham. field

DIOBETH institute.
CLUB LIBRARY.