A 595069
تور
GODOLPHIN SCHOOL.
MIDSUMMER, 1865.

ARTES
LIBRARY
1837
SCIENTIA
VERITAS
OF THE
UNIVERSITY OF MICHIGAN
PLURIBUS UNUM
ARABAN
TUEBUR
SI-QUAERIS PENINSULAM AMOE NAME,
CIRCUMSPICE

818
QL
50
.467
STUDIES IN ANIMAL LIFE.

STUDIES IN ANIMAL LIFE.
Day& Son Lifh to the Quem.
Published by Smith, Elder & Co 65. Cornhill London, 1862.

STUDIES IN ANIMAL LIFE.
41553
BY
GEORGE HENRY LEWES,
99 66
THE LIFE OF GOETHE," SEA-SIDE STUDIES,"
"PHYSIOLOGY OF COMMON LIFE," ETC.
AUTHOR OF
"Authentic tidings of invisible things-
Of ebb and flow, and ever-during power,
And central peace subsisting at the heart
Of endless agitation."-THE EXCURSION.
LONDON:
SMITH, ELDER AND CO., 65, CORNHILL.
M.DCCC.LXII.
[The right of Translation is reserved.]
PREFACE.
The following pages are reprinted from
the Cornhill Magazine. The additional
matter is confined to Notes at the end
of the chapters, on points where criticism,
and the advance of science, have caused me
to qualify, or retract, certain statements
made in the text.
It was my original intention to have con-
tinued these essays, so as to touch on Life
in the garden, the forest, and the sea. But
circumstances having prevented the execu-
tion of that project, and the publishers con-
sidering that the part already executed may
possibly not be unacceptable, I have agreed
to their proposal for its republication.
16, Blandford Square,
February, 1862.
Διὸ δεῖ μὴ δυσχεραίνειν παιδικῶς τὴν περὶ τῶν ἀτιμοτέρων ζῴων
ἐπίσκεψιν. ἐν πᾶσι γὰρ τοῖς φυσικοῖς ἔνεστί τι θαυμαστόν. . . εἰ
δὲ τις τὴν περὶ τῶν ἄλλων ζῴων θεωρίαν ἄτιμον εἶναι νενόμικε,
τὸν αὐτὸν τρόπον οἴεσθαι χρὴ καὶ περὶ αὐτοῦ.-ARISTOTLE, De
Partibus, I. 5.
"Nor must we childishly feel contempt for the study of the
lower animals, since in all Nature's work there is something
wonderful. . . . And if anyone thinks the study of other animals
despicable, he must despise the study of his own nature.”
CONTENTS.
CHAPTER I.
Omnipresence of Life-The Microscope-An Opalina and its
wonders-The uses of Cilia-How our lungs are protected from
dust and filings—Feeding without a mouth or stomach—What is
an organ ?-How a complex organism arises-Early stages of a
frog and a philosopher-How the plants feed-Parasites of the
frog-Metamorphoses and migrations of Parasites-Life within
Life-The budding of animals-A steady bore-Philosophy of
the infinitely little
Additional Note.-On the entrance of dust into the lungs
CHAPTER II.
Ponds and rock-pools-Our necessary tackle-Wimbledon Common
-Early memories-Gnat larvæ-Entomostraca and their para-
doxes—Races of animals dispensing with the sterner sex-In-
significance of males-Volvox globator: is it an animal?-Plants
swimming like animals-Animal retrogressions-The Dytiscus
and its larva―The Dragon-fly larva-Molluscs and their eggs—
Polypes, and how to find them-A new polype, Hydra rubra—
Nest-building fish-Contempt replaced by reverence
Additional Note.-On the Hydra Rubra
CHAPTER III.
•
A garden wall, and its traces of past life-Not a breath perishes
-A bit of dry Moss and its inhabitants-The "Wheel-bearers "
-Resuscitation of Rotifers: drowned into life-Current belief
that animals can be revived after complete desiccation-Experi-
ments contradicting the belief-Spallanzani's testimony-Value
of biology as a means of culture-Classification of animals: the
five great types-Criticism of Cuvier's arrangement
Additional Note.-On the resuscitation of animals
•
PAGE
Ι
•
42
46
73
A
.7
110
viii
CONTENTS.
CHAPTER IV.
An extinct animal recognized by its tooth: how came this to be
possible? — The task of classification-Artificial and natural
methods-Linnæus, and his baptism of the animal kingdom: his
scheme of classification-What is there underlying all true classi-
fication?—The chief groups-What is a species?-Re-statement
of.the question respecting the fixity or variability of species-The
two hypotheses-Illustration drawn from the Romance languages
-Caution to disputants
CHAPTER V.
Talking in beetles-Identity of Egyptian animals with those now
existing does this prove fixity of species?-Examination of the
celebrated argument of species not having altered in four thousand
years-Impossibility of distinguishing species from varieties-
The affinities of animals-New facts proving the fertility of
Hybrids-The hare and the rabbit contrasted-Doubts respect-
ing the development hypothesis-On hypothesis in Natural
History-Pliny, and his notion on the formation of pearls-Are
pearls owing to a disease of the oyster ?-Formation of the shell;
origin of pearls-How the Chinese manufacture pearls
CHAPTER VI.
Every organism a colony-What is a paradox?—An organ is an
independent individual, and a dependent one-A branch of coral
—A colony of polypes-The Siphonophora-Universal depend-
ence-Youthful aspirings-Our interest in the youth of great men
-Genius and labour-Cuvier's college life; his appearance in
youth; his arrival in Paris-Cuvier and Geoffroy St. Hilaire-
Causes of Cuvier's success-One of his early ambitions-M. le
Baron-Omnia vincit labor-Conclusion
•
Page
114
143
172
STUDIES IN ANIMAL LIFE,
CHAPTER I.
Omnipresence of Life-The Microscope-An Opalina and its
wonders-The uses of Cilia-How our lungs are protected
from dust and filings-Feeding without a mouth or stomach-
What is an organ?-How a complex organism arises-Early
stages of a frog and a philosopher-How the plants feed-
Parasites of the frog - Metamorphoses and migrations of
Parasites-Life within life-The budding of animals — A
steady bore-Philosophy of the infinitely little.
COME with me, and lovingly study Nature, as she
breathes, palpitates, and works under myriad
forms of Life-forms unseen, unsuspected, or
unheeded by the mass of ordinary men. Our
course may be through park and meadow, garden
and lane, over the swelling hills and spacious
heaths, beside the running and sequestered
streams, along the tawny coast, out on the dark
and dangerous reefs, or under dripping caves and
slippery ledges. It matters little where we go:
1
2
STUDIES IN ANIMAL LIFE.
everywhere—in the air above, the earth beneath,
and waters under the earth-we are surrounded
with Life. Avert the eyes awhile from our human
world, with its ceaseless anxieties, its noble sor-
row, poignant, yet sublime, of conscious imper-
fection aspiring to higher states, and contemplate
the calmer activities of that other world with
which we are so mysteriously related. It is an
exclusive philosophy which declares-
"The proper study of mankind is man ;"
and if it is going too far to say, as some enthu-
siastic students seem to think, that
"The proper study of mankind is cells;"
I would suggest that, if man is the noblest study,
yet under the noblest there are other problems
which demand our care. Man himself is imper-
fectly known, because the laws of universal Life
are imperfectly known. His Life forms but one
grand illustration of Biology—the science of Life.*
He forms but the apex of the animal world.
* The needful term Biology (from bios, life, and logos, dis-
course) is now becoming generally adopted in England, as in
Germany. It embraces all the separate sciences of Botany,
Zoology, Comparative Anatomy, and Physiology.
STUDIES IN ANIMAL LIFE.
3
Our studies in these pages will be of Life, and
chiefly of those minuter, or obscurer forms, which
seldom attract attention. In the air we breathe,
in the water we drink, in the earth we tread on,
Life is everywhere. Nature lives: every pore
is bursting with Life; every death is only a new
birth, every grave a cradle. And of this we know
Around us, above us,
so little, think so little!
beneath us, the great mystic drama of creation
is being enacted, and we will not even consent
to be spectators. Unless animals are obviously
useful, or obviously hurtful to us, we disregard
them. Yet they are not alien, but akin. The
Life that stirs within us, stirs within them.
We are all parts of one transcendent whole."
The scales fall from our eyes when we think of
this; it is as if a new sense had been vouch-
safed to us; and we learn to look at Nature
with a more intimate and personal love.
Life everywhere! The air is crowded with birds
-beautiful, tender, intelligent birds, to whom life
is a song and a thrilling anxiety, the anxiety of
love. The air is swarming with insects-those
1-2
4
STUDIES IN ANIMAL LIFE,
little animated miracles. The waters are peopled
with innumerable forms, from the animalcule, so
small that one hundred and fifty millions of them
would not weigh a grain, to the whale, so large
that it seems an island as it sleeps upon the
waves. The bed of the seas is alive with polypes,
crabs, star-fishes, and with myriads of shell-
animalcules. The rugged face of rocks is scarred
by the silent boring of soft creatures; and black-
ened with countless mussels, barnacles, and
limpets.
Life everywhere! on the earth, in the earth,
crawling, creeping, burrowing, boring, leaping,
running. If the sequestered coolness of the wood
tempt us to saunter into its chequered shade, we
are saluted by the murmurous din of insects, the
twitter of birds, the scrambling of squirrels, the
startled rush of unseen beasts, all telling how
populous is this seeming solitude. If we pause
before a tree, or shrub, or plant, our cursory
and half-abstracted glance detects a colony of
various inhabitants. We pluck a flower, and in
its bosom we see many a charming insect busy
STUDIES IN ANIMAL LIFE.
5
at its appointed labour. We pick up a fallen
leaf, and if nothing living is visible on it, there
is probably the trace of an insect larva hidden
in its tissue, and awaiting there development.
The drop of dew upon this leaf may possibly
contain its animals, visible under the micro-
scope. This same microscope reveals that the
blood-rain suddenly appearing on bread, and
awakening superstitious terrors, is nothing but
a collection of minute animals (Monas prodi-
giosa); and that the vast tracts of snow which
are reddened in a single night, owe their colour
to the marvellous rapidity in reproduction of a
minute plant (Protococcus nivalis). The very
mould which covers our cheese, our bread, our
jam, or our ink, and disfigures our damp walls,
is nothing but a collection of plants. The many-
coloured fire which sparkles on the surface of a
summer sea at night, as the vessel ploughs her
way, or which drips from the oars in lines of
jewelled light, is produced by millions of minute
animals.
Nor does the vast procession end here. Our
6
STUDIES IN ANIMAL LIFE.
very mother-earth is formed of the débris of
life. Plants and animals which have been, build
up its solid fabric.* We dig downwards, thou-
sands of feet below the surface, and discover with
surprise the skeletons of strange, uncouth animals,
which roamed the fens and struggled through
the woods, before man was.
Our surprise is
heightened when we learn that the very quarry
itself is mainly composed of the skeletons of
microscopic animals; the flints which grate
beneath the carriage wheels are but the remains
of countless skeletons. The Apennines and Cor-
dilleras, the chalk cliffs so dear to homeward-
nearing eyes-these are the pyramids of bygone
generations of atomies. Ages ago, these tiny
architects secreted the tiny shells, which were
their palaces; from the ruins of these palaces
we build our Parthenons, our St. Peters, and
our Louvres. So revolves the luminous orb of
Life! Generations follow generations; and the
* See EHRENBERG: Microgeologie: das Erden und Felsen
schaffende Wirken des unsichtbar kleinen selbstständigen Lebens
auf der Erde. 1854.
STUDIES IN ANIMAL LIFE.
17
↑
Present becomes the matrix of the Future, as
the Past was of the Present: the Life of one
epoch forming the prelude to a higher Life.
When we have thus ranged air, earth, and water,
finding everywhere a prodigality of living forms,
visible and invisible, it might seem as if the survey
were complete. And yet it is not so. Life cradles
within Life. The bodies of animals are little
worlds, having their own animals and plants. A
well known Frenchman has published a thick
octavo volume devoted to the classification and
description of "The plants which grow on Men
and Animals;"* and many Germans have
described the immense variety of animals which
grow on and in men and animals; so that science
can now boast of a parasitic Flora and Fauna.
In the fluids and tissues, in the eye, in the liver,
in the stomach, in the brain, in the muscles, are
found parasites; and these parasites have often
their parasites living in them!
We have thus taken a bird's-eye view of the
* CHARLES ROBIN: Histoire Naturelle des Végétaux Parasites
qui croissent sur l'Homme et sur les Animaux Vivants. 1853.
8
STUDIES IN ANIMAL LIFE.
field in which we may labour. It is truly inex-
haustible. We may begin where we please, we
shall never come to an end; our curiosity will
never slacken.
"And whosoc'er in youth
Has thro' ambition of his soul given way
To such desires, and grasp'd at such delights,
Shall feel congenial stirrings, late and long.”
If you
As a beginning, get a microscope.
cannot borrow, boldly buy one. Few purchases
will yield you so much pleasure; and while you
are about it, do, if possible, get a good one.
Spend as little money as you can on accessory
apparatus and expensive fittings, but get a good
stand and good glasses. Having got your instru-
ment, bear in mind these two important trifles-
work by daylight, seldom or never by lamplight ;
and keep the unoccupied eye open. With these
precautions you may work daily for hours without
serious fatigue to the eye.
Now where shall we begin? Anywhere will do.
This dead frog, for example, that has already
been made the subject of experiments, and is now
awaiting the removal of its spinal cord, will serve
STUDIES IN ANIMAL LIFE.
9
us as a text from which profitable lessons may be
drawn. We snip out a portion of its digestive
tube, which from its emptiness seems to promise
little; but a drop of the liquid we find in it is
placed on a glass slide, covered with a small piece
of very thin glass, and brought under the micro-
scope. Now look. There are several things which
might occupy your attention; but disregard them
Fig. 1.
A
B


OPALINA RANARUM.
A Front view
B
Side view
} Magnified.
now to watch that animalcule which you observe
swimming about. What is it? It is one of the
10
STUDIES IN ANIMAL LIFE.
largest of the Infusoria, and is named Opalina.
When I call this an Infusorium I am using the
language of text-books; but there seems to be a
growing belief among zoologists that the Opalina
is not an Infusorium, but the infantile condition
of some worm (Distoma ?). However, it will not
grow into a mature worm as long as it inhabits
the frog; it waits till some pike, or bird, has
devoured the frog, and then, in the stomach of its
new captor, it will develop into its mature form :
then, and not till then. This surprises you?
And well it may; but thereby hangs a tale, which
to unfold-for the present, however, it must be
postponed, because the Opalina itself needs all
our notice.
Observe how transparent it is, and with what
easy, undulating grace it swims about; yet this
swimmer has no arms, no legs, no tail, no back-
bone to serve as a fulcrum to moving muscles:
nay, it has no muscles to move with. 'Tis a
creature of the most absolute abnegations: sans
eyes, sans teeth, sans everything;-no, not sans
everything, for as we look attentively we see
STUDIES IN ANIMAL LIFE.
11
certain currents produced in the liquid, and on
applying a higher magnifying power we detect
how these currents are produced. All over the
surface of the Opalina there are delicate hairs, in
incessant vibration: these are the cilia.* They
lash the water, and the animal is propelled by
their strokes, as a galley by its hundred oars.
This is your first sight of that "ciliary action "
of which you have so often read, and which you
will henceforth find performing some important
service in almost every animal you examine.
Sometimes the cilia act as instruments of loco-
motion; sometimes as instruments of respiration,
by continually renewing the current of water ;
sometimes as the means of drawing in food-for
which purpose they surround the mouth, and by
their incessant action produce a small whirlpool
into which the food is sucked. An example of
this is seen in the Vorticella (Fig. 2).
Having studied the action of these cilia in micro-
scopic animals, you will be prepared to understand
* From cilium, a hair.
12
STUDIES IN ANIMAL LIFE.
their office in your own organism. The lining
membrane of your air-passages is covered with
Fig. 2.

A
D
B
C
Group of VORTICELLA NEBULIFERA, on a Stem of Weed,
Magnified.
A One undergoing spontaneous division.
B Another spirally retracted on its stalk.
C One with cilia retracted.
D A bud detached and swimming free.
cilia; which may be observed by following the
directions of Professor Sharpey, to whom science
STUDIES IN ANIMAL LIFE.
13
is indebted for a very exhaustive description of
these organs.
"To see them in motion, a portion
of the ciliated mucous membrane may be taken
from a recently-killed quadruped. The piece of
membrane is to be folded with its free, or ciliated,
surface outwards, placed on a slip of glass, with a
little water or serum of blood, and covered with
thin glass or mica. When it is now viewed with
a power of 200 diameters, or upwards, a very
obvious agitation will be perceived on the edge of
the fold, and this appearance is caused by the
moving cilia with which the surface of the mem-
brane is covered. Being set close together, and
moving simultaneously or in quick succession, the
cilia, when in brisk action, give rise to the
appearance of a bright transparent fringe along
the fold of the membrane, agitated by such a
rapid and incessant motion that the single threads
which compose it cannot be perceived.
motion here meant is that of the cilia themselves ;
but they also set in motion the adjoining fluid,
driving it along the ciliated surface, as is indi-
cated by the agitation of any little particles that
The
14
STUDIES IN ANIMAL LIFE.
The fact of the
may accidentally float in it.
conveyance of fluids and other matters along the
ciliated surface, as well as the direction in which
they are impelled, may also be made manifest by
immersing the membrane in fluid, and dropping
on it some finely-pulverized substance (such as
charcoal in fine powder), which will be slowly but
steadily carried along in a constant and deter-
minate direction.”*
•
It is an interesting fact, that while the direction
in which the cilia propel fluids and particles is
generally towards the interior of the organism,
it is sometimes reversed; and, instead of beating
the particles inwards, the cilia energetically beat
them back, if they attempt to enter. Fatal results
would ensue if this were not so. Our air-passages
would no longer protect the lungs from particles
of sand, coal-dust, and filings, flying about the
atmosphere; on the contrary, the lashing hairs
which cover the surface of these passages would
* Quain's Anatomy. By SHARPEY and ELLIS. Sixth edition.
I., p. lxxiii. See also SHARPET's article, Cilia, in the Cyclo-
pædia of Anatomy and Physiology.
STUDIES IN ANIMAL LIFE.
15
catch up every particle, and drive it onwards into
the lungs.
Fortunately for us, the direction of
the cilia is reversed, and they act as vigilant
janitors, driving back all vagrant particles with
a stern "No admittance-even on business!"
In vain does the whirlwind dash a column of
dust in our faces-in vain does the air, darkened
with coal-dust, impetuously rush up the nostrils :
the air is allowed to pass on, but the dust is
inexorably driven back. Were it not so, how
could miners, millers, iron-workers, and all the
modern Tubal Cains contrive to live in their
loaded atmospheres ? In a week their lungs would
be choked up.
Perhaps you will tell me that this is the case:
that manufacturers of iron and steel are very
subject to consumption; and that there is a
peculiar discoloration of the lungs which has
often been observed in coal miners, examined
after death.
Not being a physician, and not intending to
trouble you with medical questions, I must never-
theless place before you three considerations,
16
STUDIES IN ANIMAL LIFE.
which will show how questionable this notion is.
First, although consumption may be frequent
among the Sheffield workmen, the cause may
perhaps be sought less in their breathing filings,
than in the sedentary and unwholesome confine-
ment incidental to their occupation. Miners and
coal-heavers are not generally troubled with con-
sumption. Moreover, if the filings were the
cause, all the artisans would suffer, when all
breathe the same atmosphere. Secondly, while
it is true that discoloured lungs have been ob-
served in some miners, it has not been observed
in all, or in many; whereas, it has been observed
in men not miners, not exposed to any unusual
amount of coal-dust. Thirdly, and most con-
clusively, experiment has shown that the coal-
dust cannot penetrate to the lungs. Claude
Bernard, the brilliant experimenter, tied a blad-
der, containing a quantity of powdered charcoal,
to the muzzle of a rabbit. Whenever the animal
breathed, the powder within the bladder was seen
to be agitated. Except during feeding time, the
bladder was kept constantly on, so that the
STUDIES IN ANIMAL LIFE.
17
animal breathed only this dusty air.
If the
powder could have escaped the vigilance of the
cilia, and got into the lungs, this was a good
occasion. But when the rabbit was killed and
opened, many days afterwards, no powder what-
ever was found in the lungs, or bronchial tubes;
several patches were collected about the nostrils.
and throat; but the cilia had acted as a strainer,
keeping all particles from the air tubes.*
*
The swimming apparatus of the Opalina has led
us far away from the little animal, who has been
feeding while we have been discussing. At the
mention of feeding, you naturally look for the food
that is eaten, the mouth and stomach that eat.
But I hinted just now that this ethereal creature
dispenses with a stomach, as too gross for its
nature; and of course, by a similar refinement,
dispenses with a mouth. Indeed, it has no organs
whatever, except the cilia just spoken of. The
same is true of several of the Infusoria; for you
must know that naturalists no longer recognize
-
* See additional NOTE at the end of the chapter, p. 42.
2
18
STUDIES IN ANIMAL LIFE.
the complex organization which Ehrenberg fancied
he had detected in these microscopic beings. If
it pains you to relinquish the piquant notion of a
microscopic animalcule having a structure equal
in complexity to that of the elephant, there will
be ample compensation in the notion which re-
places it-the notion of an ascending complexity
of animal organisms, rising from the structureless
amaba to the complex frame of a mammal. On
a future occasion we shall see that, great as
Ehrenberg's services have been, his interpreta-
tions of what he saw have one by one been
replaced by truer notions. His immense class of
Infusoria has been, and is constantly being,
diminished; many of his animals turn out to be
plants; many of them larvæ of worms; and some
of them belong to the same divisions of the animal
kingdom as the oyster and the shrimp: that is
to say, they range with the Molluscs and Crus-
taceans. In these latter, of course, there is a
complex organization; but in the Infusoria, as
now understood, the organization is extremely
simple. No one now believes the clear spaces
STUDIES IN ANIMAL LIFE.
19
visible in their substance to be stomachs, as
Ehrenberg believed; and the idea of the Poly-
gastrica, or many-stomached Infusoria, is aban-
doned. No one believes the coloured specs to
be eyes; because, not to mention the difficulty
of conceiving eyes where there is no nervous
system, it has been found that even the spores
of some plants have these coloured specs; and
they are assuredly not eyes. If, then, we exclude
the highly-organized Rotifera, or "Wheel Ani-
malcules," we may say that all Infusoria, whether
they be the young of worms or not, are of very
simple organization.
And this leads us to consider what biologists
mean by an organ: it is a particular portion of
the body set apart for the performance of some
particular duty. The whole process of develop-
ment consists in this "setting apart" for special
purposes. The starting-point of Life is a single
cell-that is to say, a microscopic sac, filled with
liquid and granules, and having within it a
nucleus, or smaller sac. Paley has somewhere
remarked, that in the early stages, there is no
2-2
20
STUDIES IN ANIMAL LIFE.
difference discernible between a frog and a philo-
sopher. It is very true; truer than he conceived.
In the earliest stage of all, both the Batrachian
and the Philosopher are nothing but single cells;
although the one cell will develop into an Aris-
totle or a Newton, and the other will get no
higher than the cold, damp, croaking animal
which boys will pelt, anatomists dissect, and
Frenchmen eat. From the starting-point of a
single cell, this is the course taken: the cell
divides itself into two, the two become four, the
four eight, and so on, till a mass of cells is
formed, not unlike the shape of a mulberry.
This mulberry-mass then becomes a sac, with
double envelopes, or walls: the inner wall, turned
towards the yelk, or food, becomes the assimi-
lating surface for the whole; the outer wall,
turned towards the surrounding medium, becomes
the surface which is to bring frog and philo-
sopher into contact and relation with the external
world-the Non-Ego, as the philosopher, in after
life, will call it. Here we perceive the first
grand setting apart," or differentiation, has
66
A
STUDIES IN ANIMAL LIFE.
21
taken place: the embryo having an assimilating
surface, which has little to do with the external
world; and a sensitive, contractile surface, which
has little to do with the preparation and trans-
port of food. The embryo is no longer a mass
of similar cells; it is already become dissimilar,
different, as respects its inner and outer envelope.
But these envelopes are at present uniform; one
part of each is exactly like the rest.
Let us,
therefore, follow the history of Development, and
we shall find that the inner wall gradually
becomes unlike itself in various parts; and that
certain organs, constituting a very complex appa-
ratus of Digestion, Secretion, and Excretion,
are all one by one wrought out of it, by a
series of metamorphoses, or differentiations. The
inner wall of the original sac thus passes from
a simple assimilating surface into a complex
apparatus serving the functions of vegetative
life.
Now glance at the outer wall of the sac: from
it also various organs have gradually been
wrought it has developed into muscles, nerves,
22
STUDIES IN ANIMAL LIFE.
bones, organs of sense, and brain: all these from
a simple homogeneous membrane !
With this bird's-eye view of the course of
Development, you will be able to appreciate the
grand law first clearly enunciated by Goethe and
Von Baer, as the law of animal life, namely, that
Development is always from the general to the
special, from the simple to the complex, from
the homogeneous to the heterogeneous; and this
by a gradual series of differentiations.* Or to
put it into the music of our deeply meditative
Tennyson :-
“All nature widens upward. Evermore
The simpler essence lower lies:
More complex is more perfect-owning more
Discourse, more widely wise."
You are
now familiarized with the words
"differentiation" and "development," often met
with in modern writers; and have gained a
distinct idea of what an organ is; so that
on hearing of an animal without organs, you will
at once conclude that in such an animal there
""
* GOETHE: Zur Morphologie, 1807. VON BAER: Zur Ent-
wickelungsgeschichte, 1828. Part I., p. 158.
STUDIES IN ANIMAL LIFE.
23
has been no setting apart of any portion of the
body for special purposes, but that all parts serve
all purposes indiscriminately.
Here is our Opalina, for example, without
mouth, or stomach, or any other organ. It is an
assimilating surface in every part; in every part
a breathing, sensitive surface. Living on liquid
food, it does not need a mouth to seize, or a
stomach to digest, such food. The liquid, or
gas, passes through the Opalina's delicate skin,
by a process which is called endosmosis; it
there serves as food; and the refuse passes out
again by a similar process, called exosmosis.
This is the way in which many animals and all
plants are nourished. The cell at the end of a
rootlet, which the plant sends burrowing through
the earth, has no mouth to seize, no open pores
to admit the liquid which it needs; nevertheless
the liquid passes into the cell, through its delicate
cell-wall, and passes from this cell to other cells,
upwards from the rootlet to the bud. It is in
this way, also, that the Opalina feeds it is
all-mouth, no-mouth; all-stomach, no-stomach.
24
STUDIES IN ANIMAL LIFE.
Every part of its body performs the functions
which in more complex animals are performed
by organs specially set apart. It feeds without
mouth, breathes without lungs, and moves with-
out muscles.
The Opalina, as I said, is a parasite. It may be
found in various animals, and almost always in
the frog. You will, perhaps, ask why it should
be considered a parasite; why may it not have
been swallowed by the frog in a gulp of water ?
Certainly, nothing would have been easier. But
to remove your doubts, and to show that since
the Opalina is always found in one organ, we may
conclude that organ to be its natural habitat: and
further research shows that each organ has its
parasite. I open the skull of this frog, and care-
fully remove a drop of the liquid found inside,
which, on being brought under the microscope,
we shall most probably find containing some ani-
malcules, especially those named Monads. These
were not swallowed. They live in the cerebro-
spinal fluid, as the Opalina lives in the digestive
tube. Thus, if we extend our researches, we
STUDIES IN ANIMAL LIFE.
25
shall find that various organs have their various.
parasites.
Here, for instance, is a parasitic worm from
the frog's bladder.
ს
Place it under the micro-
Fig. 3.

a
d
C
e
e
POLYSTOMUM INTEGERRIMUM, Magnified.
scope, with a high power, and behold! It is
called Polystomum-many-mouthed, or, more pro-
perly, many-suckered.
You are looking at the
under side, and will observe six large suckers
with their starlike clasps (e), and the horny
26
STUDIES IN ANIMAL LIFE.
instrument (ƒ), with which the animal bores its
way. At a there is another sucker, which serves
also as a mouth; at b you perceive the rudiment
of a gullet, and at d the reproductive organs.
But pay attention to the pretty branchings of
the digestive tube (c), which ramifies through
the body like a blood-vessel.
This arrangement of the digestive tube is found
in many animals, and is often mistaken for a
system of blood-vessels. In one sense this is
correct; for these branching tubes are carriers of
nutriment, and the only circulating vessels such
animals possess; but the nutriment is chyme,
not blood these simple animals have not arrived
at the dignity of blood, which is a higher elabo-
ration of the food, fitted for higher organisms.
Thus may our frog, besides its own marvels,
afford us many "authentic tidings of invisible
things," being itself a little colony of life. Nature
is economic as well as prodigal of space. She
fills the illimitable heavens with planetary and
starry grandeurs, and she makes the tiny atoms.
moving over the crust of earth the homes of
STUDIES IN ANIMAL LIFE.
27
the infinitely little. Far as the mightiest tele-
scope can reach, it detects worlds in clusters,
like pebbles on the shores of Infinitude; deep
as the microscope can penetrate, it detects Life
within Life, generation within generation; as if
the very Universe itself were not vast enough
for the energies of Life.
That phrase, generation within generation, was
not a careless phrase; it is exact. Take the
tiny insect (Aphis) which, with its companions,
crowds your rose-tree; open it, in a solution of
sugar-water, under your miscroscope, and you
will find inside it a young insect nearly formed;
open that young insect with care, and you will
find in it, also, another young one, less advanced
in its development, but perfectly recognizable to
the experienced eye; and beside this embryo you
will find many eggs, which would in time become
insects!
Or take that lazy water-snail (Paludina vivi-
para), first made known to science by that in-
carnation of patience and exactness, the great
Swammerdamm, and you will find, as he found,
28
STUDIES IN ANIMAL LIFE.
forty or fifty young snails, in various stages of
development; and you will also find, as he found,
some tiny worms, which, if you cut them open,
will suffer three or four infusoria to escape from
the opening.* In your astonishment you will
ask, Where is this to end?
The observation recorded by Swammerdamm,
like so many others of this noble worker, fell
into neglect; but modern investigators have made
it the starting-point of a very curious inquiry.
The worms he found within the snail are now
called Cercaria-sacs, because they contain the
Cercaria, once classed as Infusoria, and which
are now known to be the early forms of parasitic
worms inhabiting the digestive tube, and other
cavities of higher animals. These Cercaria have
vigorous tails, with which they swim through
the water like tadpoles; and like tadpoles, they
lose their tails in after life. But how, think
you, did these sacs containing Cercaria get into
the water-snails? "By spontaneous generation,"
* SWAMMERDAMM. Bibel der Natur, pp. 75-77.
STUDIES IN ANIMAL LIFE.
29
formerly said the upholders of that hypothesis;
and those who condemned the hypothesis, were
forced to admit they had no better explanation.
It was a mystery, which they preferred leaving
unexplained, rather than fly to spontaneous gene-
ration. And they were right. The mystery has
at length been cleared up.* I will endeavour to
bring together the scattered details, and narrate
the curious story.
Under the eyelids of geese and ducks may be
constantly found a parasitic worm (of the Trema-
tode order), which naturalists have christened
Monostomum mutabile-Single-mouth Change-
able. This worm brings forth living young in
the likeness of active Infusoria, which, being
covered with cilia, swim about in the water, as
we saw the Opalina swim. Here is a portrait
of one. (Fig. 4.)
Each of these animalcules develops a sac in-
its interior. The sac you may notice in the
* By VON SIEBOLD. See his interesting work, Ueber die
Band-und-Blasenwürmer. It has been translated by HUXLEY,
and appended to the translation of KUECHENMEISTER on Para-
sites, published by the Sydenham Society.
I
30
STUDIES IN ANIMAL LIFE.
engraving.
Having managed to get into the
body of the water-snail, the animalcule's part
с
b
Fig. 4.
A
B

CL


A EMBRYO OF MONOSTOMUM MUTABIle.
a Mouth; b Pigment spots; c Sac.-Magnified.
B Cercaria sac, just set free.
in the drama is at an end. It dies, and in
dying liberates the sac, which is then very com-
fortably housed and fed by the sail. If you
examine this sac minutely (Fig. 5), you will ob-
serve that it has a mouth and digestive tube,
and is, therefore, very far from being, what its
name imports, a mere receptacle; it is an inde-
pendent animal, and lives an independent life.
It feeds generously on the juices of the snail,
and having fed, thinks generously of the coming
generations. It was born inside the animal-
STUDIES IN ANIMAL LIFE.
31
cule; why should it not in turn give birth to
children of its own? To found a dynasty, to
scatter progeny over the bounteous earth, is a
worthy ambition. The mysterious agency of
Reproduction begins in this sac-animal; and in
a short while a brood of Cercaria move within
Fig. 5.
C
B
A
Fig. 6.

A
C

B
D
B
B
CERCARIA SAC.
A Mouth;
B Digestive tube;
CA Cercaria newly
formed. Four others
are seen in different
stages.-Magnified.
CERCARIA DEVELOPED.
A Mouth;
B, B, B Excretory organ;
C Pigment spots;
D Tail.
it. The sac bursts, and the brood escapes. But
how is this? The children are by no means
the "
very image" of their parent. They are
not sacs, nor in the least resembling sacs, as
you see. (Fig. 6.)
32
STUDIES IN ANIMAL LIFE.
They have tails, and suckers, and sharp boring
instruments, with other organs which their parent
was without. To look at them you would as
soon suspect a shrimp to be the progeny of an
oyster, as these to be the progeny of the sac-
animal. And what makes the paradox more
paradoxical is, that not only are the Cercariæ
unlike their parent, but their parent was equally
unlike its parent, the embryo of Monostomum
(compare Fig. 4). However, if we pursue this
family history, we shall find the genealogy rights
itself at last, and that this Cercaria will develop
in the body of some bird into a Monostomum
mutabile like its ancestor. Thus the worm pro-
duces an animalcule, which produces a sac-animal,
which produces a Cercaria, which becomes a
worm exactly resembling its great-grandfather.
One peculiarity in this history is that while the
Monostomum produces its young in the usual
way, the two intermediate forms are produced
by a process of budding, analogous to that ob-
served in plants. Plants, as you know, are
reproduced in two ways, from the seed, and from
STUDIES IN ANIMAL LIFE.
33
the bud. For seed-reproduction, peculiar organs
are necessary; for bud-reproduction, there is no
such differentiation needed: it is simply an out-
growth. The same is true of many animals :
they also bud like plants, and produce seeds
(eggs) like plants. I have elsewhere argued that
the two processes are essentially identical; and
that both are but special forms of growth.* Not,
however, to discuss so abstruse a question here,
let us merely note that the Monostomum, into
which the Cercaria will develop, produces eggs,
from which young will issue; the second genera-
tion is not produced from eggs, but by internal
budding; the third generation is likewise budded
internally; but it, on acquiring maturity, will
produce eggs. For this maturity, it is indis-
pensable that the Cercaria should be swallowed
by some bird or animal; only in the diges-
tive tube can it acquire its egg-producing con-
dition. How is it to get there? The ways
are many; let us witness one:-
* Seaside Studies, pp. 308, sq.; 2nd edition, pp. 326, sq.
3
34
STUDIES IN ANIMAL LIFE.
In this watch-glass of water we have several
Cercaria swimming about. To them we add
three or four of those darting, twittering insects
which you have seen in every vase of pond-
water, and have learned to be the larvæ, or early
forms, of the Ephemeron. The Cercaria cease
flapping the water with their impatient tails,
and commence a severe scrutiny of the strangers.
When Odry, in the riotous farce, Les Saltim-
banques, finds a portmanteau, he exclaims, "Une
malle! ce doit être à moi!" ("Surely this
must belong to me!") This seems to be the
theory of property adopted by the Cercaria: “An
insect! surely this belongs to me!" Accord-
ingly every one begins creeping over the bodies
of the Ephemeron, giving an interrogatory poke
with the spine, which will pierce the first soft
place it can detect. Between the segments of
the insect's armour a soft and pierceable spot.
is found; and now, lads, to work! Onwards
they bore, never relaxing in their efforts till a
hole is made large enough for them to slip in
by elongating their bodies. Once in, they dis-
STUDIES IN ANIMAL LIFE.
35
miss their tails as useless appendages; and begin
what is called the process of encysting—that is,
of rolling themselves up into a ball, and secret-
ing a mucus from their surface, which hardens
round them like a shell. Thus they remain
snugly ensconced in the body of the insect, which
in time develops into a fly, hovers over the pond,
and is swallowed by some bird. The fly is
digested, and the liberated Cercaria finds com-
fortable quarters in the bird's digestive tube, its
shell is broken, and its progress to maturity is
rapid.
Von Siebold's description of another form of
emigration he has observed in parasites will be
read with interest. "For a long time," he says,
"the origin of the thread worm, known as Filaria
insectorum, that lives in the cavity of the bodies
of adult and larval insects, could not be accounted
for. Shut up within the abdominal cavity of
caterpillars, grasshoppers, beetles, and other in-
sects, these parasites were supposed to originate
by spontaneous generation, under the influence of
wet weather or from decayed food.
Helmintho-
3-2
36
STUDIES IN ANIMAL LIFE.
logists (students of parasitic worms) were obliged
to content themselves with this explanation, since
they were unable to find a better. Those who
dissected these threadworms and submitted them
to a careful inspection, could not deny the pro-
bability, since it was clear that they contained no
trace of sexual organs. But on directing my
attention to these entozoa, I became aware of
the fact that they were not true Filaria at all,
but belonged to a peculiar family of thread-
worms, embracing the genera of Gordius and
Mermis. Furthermore, I convinced myself that
these parasites wander away when full-grown,
boring their way from within through any soft
place in the body of their host, and creeping
out through the opening. These parasites do
not emigrate because they are uneasy, or because
the caterpillar is sickly; but from that same in-
ternal necessity which constrains the horsefly to
leave the stomach of the horse where he has been
reared, or which moves the gadfly to work its
way out through the skin of the oxen. The
larvæ of both these insects creep forth in order
STUDIES IN ANIMAL LIFE.
37
to become chrysalises, and thence to proceed to
their higher and perfect condition. I have de-
monstrated that the perfect, full-grown, but sexless
threadworms of insects are in like manner moved
by their desire to wander out of their previous
homes, in order to enter upon a new period of
their lives, which ends in the development of
their sex. As they leave the bodies of their
hosts they fall to the ground, and crawl away
into the deeper and moister parts of the soil.
Threadworms found in the damp earth, in dig-
ging up gardens and cutting ditches, have often
been brought to me, which presented no external
distinctions from the threadworms of insects.
This suggested to me that the wandering thread-
worms of insects might instinctively bury them-
selves in damp ground, and I therefore instituted
a series of experiments by placing the newly-
emigrated worms in flower-pots filled with damp
earth. To my delight I soon perceived that
they began to bore with their heads into the
earth and by degrees drew themselves entirely
in. For many months I kept the earth in the
38
STUDIES IN ANIMAL LIFE.
flower-pots moderately moist, and on examining
the worms from time to time I found they had
gradually attained their sex-development, and
eggs were deposited in hundreds. Towards the
conclusion of winter I could succeed in detecting
the commencing development of the embryos in
these eggs. By the end of spring they were fully
formed, and many of them having left their
shells were to be seen creeping about the earth.
I now conjectured that these young worms would
be impelled by their instincts to pursue a para-
sitic existence, and to seek out an animal to in-
habit and to grow to maturity in; and it seemed
not improbable that the brood I had reared
would, like their parents, thrive best in the cater-
pillar. In order, therefore, to induce my young
brood to immigrate, I procured a number of very
small caterpillars which the first spring sunshine
had just called into life. For the purpose of my
experiment I filled a watch-glass with damp earth,
taking it from amongst the flower-pots where the
threadworms had wintered. Upon this I placed
several of the young caterpillars." The result
STUDIES IN ANIMAL LIFE.
39
was as he expected; the caterpillars were soon
bored into by the worms, and served them at
once as food and home.*
Frogs and parasites, worms and infusoria-are
these worth the attention of a serious man?
They have a less imposing appearance than
planets and asteroids, I admit, but they are nearer
to us, and admit of being more intimately known;
and because they are thus accessible, they become
more important to us. The life that stirs within
us is also the life within them. It is for this
reason, as I said at the outset, that although
man's noblest study must always be man, there
are other studies less noble, yet not therefore
ignoble, which must be pursued, even if only
with a view to the perfection of the noblest.
Many men, and those not always the ignorant,
whose scorn of what they do not understand is
always ready, despise the labours which do not
obviously and directly tend to moral or political
advancement. Others there are, who, fascinated
* VON SIEBOLD: Ueber Band-und-Blasenwürmer. HUXLEY'S
translation is here adopted.
40
STUDIES IN ANIMAL LIFE.
by the grandeur of Astronomy and Geology, or
by the immediate practical results of Physics and
Chemistry, disregard all microscopic research as
little better than dilettante curiosity. But I can-
not think any serious study is without its serious
value to the human race; and I know that the
great problem of Life can never be solved while
we are in ignorance of its simpler forms. Nor
can anything be more unwise than the attempt
to limit the sphere of human inquiry, especially
by applying the test of immediate utility. All
truths are related; and however remote from our
daily needs some particular truth may seem, the
time will surely come when its value will be felt.
To the majority of our countrymen during the
Revolution, when the conduct of James II.
seemed of incalculable importance, there would
have seemed something ludicrously absurd in the
assertion that the newly-discovered differential
calculus was infinitely more important to Eng-
land and to Europe than the fate of all the
dynasties; and few things could have seemed
more remote from any useful end than this pro-
STUDIES IN ANIMAL LIFE.
41
duct of mathematical genius; yet it is now clear
to every one that the conduct of James was
supremely insignificant in comparison with this
discovery. I do not say that men were unwise
to throw themselves body and soul into the
Revolution; I only say they would have been
unwise to condemn the researches of mathe-
maticians.
From
Let all who have a longing to study Nature
in any of her manifold aspects, do so without
regard to the sneers or objections of men whose
tastes and faculties are directed elsewhere.
the illumination of many minds on many points,
Truth must finally emerge. Man is, in Bacon's
noble phrase, the minister and interpreter of
Nature; let him be careful lest he suffer this
ministry to sink into a priesthood, and this
interpretation to degenerate into an immovable
dogma. The suggestions of apathy, and the
prejudices of ignorance, have at all times inspired
the wish to close the temple against new comers.
Let us be vigilant against such suggestions, and
keep the door of the temple ever open.
42
STUDIES IN ANIMAL LIFE.
ADDITIONAL NOTE.
ON THE ENTRANCE OF DUST INTO THE LUNGS.
On this important subject of the possibility of
dust and filings gaining entrance to the lungs,
in spite of the opposing cilia, I have received
so many communications from correspondents
and medical friends, that although I have left
the passage in the text, it seems necessary to
add an important qualification here. It appears,
from information volunteered to me, that dust
and filings, recognizable under the microscope
and under chemical reactions, have very fre-
quently been found in the lungs of miners and
Sheffield artisans. There is no resisting the
evidence. It is further shown that when the
quantity of filings in the atmosphere is dimi-
nished by wet-grinding, or other mechanical con-
trivances, the amount of lung disease among
the workmen is considerably lessened.
Let these facts be duly considered. But, on
the other hand, let not these facts lead to a
STUDIES IN ANIMAL LIFE.
43
denial of the important physiological results of
Claude Bernard's experiments. In Nature there
is no contradiction. One positive fact is not to
be set aside by twenty other positive facts;
not to be set aside, but if possible to be ranged
with them under some more general fact.
While I am perfectly ready to admit the cor-
rectness of the statements made by my corre-
spondents, and to withdraw the absolute denial
formerly made, as to the possibility of dust
entering the lungs; I can only replace it by
the assertion, that this possibility is usually
counteracted by the presence of the cilia; and
that in normal cases healthy animals do not
admit dust into their lungs. Were there no
such normal rule, the continued existence of
animals in a smoky, dusty, filing-loaded atmo-
sphere would be impossible, except under con-
ditions of perpetual lung-disease. The particles
of coal, sand, and steel would be carried by
the bronchial vessels into their ultimate rami-
fications, and there form deposits, or work
through into the parenchyma of the lungs. This,
44
STUDIES IN ANIMAL LIFE.
it appears, is actually the case in some miners
and steel-grinders. But why is it not so in
all? and even in those who are thus affected,
why is the deposit so small? Surely it is not
so in all, because the healthy organism is con-
structed not to allow the entrance of such par-
ticles; and if in certain feebler organisms there
be a possibility of entrance, even this must be
but slight, seeing how long a period of exposure
elapses before the disease becomes manifest.
The reader will be pleased to understand, that
in these remarks I wish to throw no sort of
doubt on the fact of miners and steel-grinders
being liable to lung disease in the course of
their avocations. On the contrary, great em-
phasis should be laid upon this liability, and
every means taken to counteract it. But this
is a special question. It is a matter of indus-
trial hygiène. The question originally mooted
by me was a general physiological question relat-
ing to the function of cilia in the animal
organism; and if I was misled into a state-
ment, too absolute in its terms, by reliance on
STUDIES IN ANIMAL LIFE.
45
Claude Bernard's experiments and deductions—
which statement I at once retract in its abso-
lute form there still remains unimpeachable
evidence for the general physiological law, that
the cilia prevent the entrance of dust into the
lungs; and those who deny this, on the strength
of the evidence furnished in exceptional cases,
must be imperfectly acquainted with the facts,
or strangely oblivious of them.
46
STUDIES IN ANIMAL LIFE.
CHAPTER II.
Ponds and rock-pools-Our necessary tackle-Wimbledon Com-
mon-Early memories—Gnat larvæ-Entomostraca and their
paradoxes-Races of animals dispensing with the sterner scx-
Insignificance of males-Volvox globator: is it an animal?-
Plants swimming like animals-Animal retrogressions-The
Dytiscus and its larva-The Dragon-fly larva-Molluscs and
their eggs-Polypes, and how to find them-A new polype,
Hydra rubra - Nest-building fish-Contempt replaced by
reverence.
THE day is bright with a late autumn sun; the
sky is clear with a keen autumn wind, which
lashes our blood into a canter as we press against
it; and the cantering blood sets the thoughts
into hurrying excitement. Wimbledon Common
is not far off; its five thousand acres of undu-
lating heather, furze, and fern tempt us across
it, health streaming in at every step as we snuff
the keen breeze. We are tempted also to bring
net and wide-mouthed jar, to ransack the many
ponds for visible and invisible wonders.
Ponds, indeed, are not so rich and lovely as
STUDIES IN ANIMAL LIFE.
47
rock-pools; the heath is less alluring than the
coast-the dear-loved coast, with its gleaming
mystery, the sea, and its sweeps of sand, its
reefs, its dripping boulders. I admit the com-
parative inferiority of ponds; but we are not
near the coast, and the heath is close at hand.
Nay, if the case were otherwise, I should object
to dwarfing comparisons. It argues a pitiful
thinness of nature (and the majority in this
respect are lean) when present excellence is
depreciated because some greater excellence is to
be found elsewhere. We are not elsewhere; we
must do the best we can with what is here.
Because ours is not the Elizabethan age, shall we
express no reverence for our great men, but
reserve it for Shakspeare, Bacon, and Raleigh,
whose traditional renown is to overshadow our
contemporaries ? Not so. To each age its
honour. Let us be thankful for all greatness,
past or present, and never speak slightingly of
noble work, or honest endeavour, because it is
not, or we choose to say it is not, equal to
something else. No comparisons then, I beg.
48
STUDIES IN ANIMAL LIFE.
If I said ponds were finer than rock-pools, you
might demur; but I only say ponds are excellent
things; let us dabble in them; ponds are rich in
wonders, let us enjoy them.
And first we must look to our tackle. It is
extremely simple. A landing-net, lined with
muslin; a wide-mouthed glass jar, say a foot
high and six inches in diameter, but the size
optional, with a bit of string tied under the lip,
and forming a loop over the top, to serve as a
handle which will let the jar swing without
spilling the water; a camel-hair brush; a quinine
bottle, or any wide-mouthed phial, for worms and
tiny animals which we desire to keep separated
from the dangers and confusions of the larger jar;
and when to these a pocket lens is added, our
equipment is complete.
As we emerge upon the common, and tread its
springy heather, what a wild wind dashes the hair
into our eyes, and the blood into our cheeks!
and what a fine sweep of horizon lies before us!
The lingering splendours and the beautiful decays
of autumn vary the scene, and touch it with a
STUDIES IN ANIMAL LIFE.
49
certain pensive charm. The ferns mingle har-
moniously their rich browns with the dark green
of the furze, now robbed of its golden summer-
glory, but still pleasant to the eye, and exquisite
to memory. The gaunt windmill on the rising
ground is stretching its stiff, starred arms into
the silent air: a landmark for the wanderer, a
landmark, too, for the wandering mind, since it
serves to recall the dim early feelings, and sweet
broken associations of childhood when we gazed
at it with awe, and listened to the rushing of its
mighty arms.
Ah! well may the mind with the sweet insist-
ance of sadness linger on those scenes of the
irrecoverable past, and try, by lingering there,
to feel that it is not wholly lost, wholly irrecover-
able, vanished for ever from the Life which, as
these decays of autumn and these changing trees
too feelingly remind us, is gliding away, leaving
our cherished ambitions still unfulfilled, and our
deeper affections still but half expressed. The
vanishing visions of elapsing life bring with them
thoughts which lie too deep for tears; and this
4
50
STUDIES IN ANIMAL LIFE.
windmill recalls such visions by the subtle laws of
association.
Let us go towards it, and stand once more
under its shadow. See the intelligent and tail-
less sheep-dog which bounds out at our approach,
eager and minatory; now his quick eye at once
recognizes that we are neither tramps, nor thieves,
and he ceases barking to commence a lively inter-
change of sniffs and amenities with our Pug, who
seems also glad of a passing interchange of com-
monplace remarks. While these dogs travel over
each other's minds, let us sun ourselves upon this
bench, and look down on the embrowned valley,
with its gipsy encampment, or abroad on the
purple Surrey hills, and the varied-tinted trees of
Combe Wood and Richmond Park.
There are
not many such prospects so near London.
But, in spite of the sun, we must not linger
here the wind is much too analytical in its
remarks; and, moreover, we came out to hunt.
Here is a pond with a mantling surface of green
promise. Dip the jar into the water. Hold it
now up to the light, and you will see an immense
STUDIES IN ANIMAL LIFE.
51
variety of tiny animals swimming about. Some
are large enough to be recognized at once;
others require a pocket-lens, unless familiarity
has already enabled you to infer the forms you
cannot distinctly see. Here (Fig. 7) are two
larvæ (or grubs) of the common gnat. That
large-headed fellow (A) bobbing about with such
B
Fig. 7.

A
LARVE OF THE GNAT in two different stages of development.
(Magnified.)
grotesque movements, is very near the last stage
of his metamorphosis; and to-morrow, or the
next day, you may see him cast aside this mask
(larva means a mask), and emerge a perfect
insect. The other (B) is in a much less matured
4-2
52
STUDIES IN ANIMAL LIFE.
condition, but leads an active predatory life,
jerking through the water, and fastening to the,
stems of weed or sides of the jar by means of
the tiny hooks at the end of its tail. The hairy
appendage forming the angle is not another tail,
but a breathing apparatus.
Fig. 8.
Fig. 9.


C
α
ს
C
CYCLOPS.
a large antennæ; b smaller do.;
c egg-sacs (Magnified).
DAPHNIA:
a pulsatile sac, or heart;
beggs; c digestive tube
(Magnified).
Observe, also, those grotesque Entomostracas,*
popularly called "water-fleas," although, as you
perceive, they have little resemblance in form or
* Entomostraca (from entomos, an insect, and ostracon, a shell)
are not really insects, but belong to the same large group of
animals as the lobster, the crab, or the shrimp, i. e. crustaceans.
STUDIES IN ANIMAL LIFE.
53
manners to our familiar (somewhat too familiar)
bedfellows. This (Fig. 8) is a Cyclops, with
only one eye in the centre of its forehead, and
carrying two sacs, filled with eggs, like panniers.
You observe he has no legs; or, rather, legs and
arms are hoisted up to the head, and become
antennæ (or feelers). Here (Fig. 9) is a Daphnia,
grotesque enough, throwing up his arms in asto-
nished awkwardness, and keeping his legs actively
at work inside the shell-as respirators, in fact.
Here (Fig. 10) is an Eurycercus, less grotesque,
Fig. 10.

b
b
α
EURYCERCUS.
a heart; beggs; c digestive tube (Magnified).
and with a much smaller eye. Talking of eyes,
there is one of these Entomostraca named Poly-
phemus, whose head is all eye; and another,
54
STUDIES IN ANIMAL LIFE.
named Caligus, who has no head at all. Other
paradoxes and wonders are presented by this
interesting group of animals;* but they all sink
into insignificance beside the paradox of the
amazonian entomostracon, the Apus-a
which dispenses with masculine services alto-
gether, a race of which there are no males!
race
I well remember the pleasant evening on which
I first made the personal acquaintance of this
amazing amazon. It was at Munich, and in the
house of a celebrated naturalist, in whose garden
an agreeable assemblage of poets, professors, and
their wives, sauntered in the light of a setting
sun, breaking up into groups and tête-à-têtes,
to re-form into larger groups. We had taken
coffee under the branching coolness of trees, and
were now loitering through the brief interval till
supper. Our host had just returned from an
expedition of some fifty miles to a particular
pond, known to be inhabited by the Apus. He
had made this journey because the race, although
* The student will find ample information in BAIRD's British
Entomostraca, published by the Ray Society.
STUDIES IN ANIMAL LIFE.
55
prolific, is rare, and is not to be found in every
spot. For three successive years had he gone to
the same pond, in quest of the male: but no male
was to be found among thousands of egg-bearing
females, some of which he had brought away with
him, and was showing us. We were amused to
see them swimming about, sometimes on their
backs, using their long oars; sometimes floating,
but always incessantly agitating the water with
their ten pairs of breathing legs; and the ladies,
gathered round the jar, were hugely elated at the
idea of animals getting rid altogether of the
sterner sex-clearly a useless incumbrance in the
scheme of things!
The fact that no male Apus has yet been found*
is not without precedent. Léon Dufour, the cele-
brated entomologist, declares that he never found
the male of the gall insect (Diplolepis galle
tinctoria), though he has examined thousands:
they were all females, and bore well-developed
* In WIEGMANN's Archiv for 1857 there is a paper by
KOZUBOSKI on the Male Apus; but VON SIEBOLD assured
me it was altogether erroneous.
56
STUDIES IN ANIMAL LIFE.
eggs on emerging from the gall-nut in which
their infancy had passed. In two other species
of gall insect-Cynips divisa and Cynips folii-
Hartig says he was unable to find a male; and
he examined about thirteen thousand. Brogniart
never found the male of another entomostracon
(Limnadia gigas), nor could Jurine find that of
our Polyphemus. These negatives prove, at least,
that if the males exist at all, they must be exces-
sively rare, and their services can be dispensed
with;
a conclusion which becomes acceptable
when we learn that bees, moths, plant-lice
(Aphides), and our grotesque friend Daphnia
(Fig. 9) lay eggs which may be reared apart,
will develop into females, and these will pro-
duce eggs which will in turn produce other
females, and so on, generation after generation,
although each animal be reared in a vessel apart
from all others.
While on this subject, I cannot forbear making
a reflection. It must be confessed that our sex
cuts but a poor figure in some great families.
If the male is in some families grander, fiercer,
STUDIES IN ANIMAL LIFE.
57
more splendid, and more highly endowed than
the female, this occasional superiority is more
than counterbalanced by the still greater infe-
riority of the sex in other families. The male
is often but a contemptible partner, puny in
size, insignificant in powers, stinted even of a
due allowance of organs. If the peacock and
the pheasant swagger in greater splendour, what
a pitiful creature is the male falcon-no falconer
will look at him. And what is the drone com-
pared with the queen bee, or even with the
workers? What figure does the male spider
make beside his large and irascible female,-
who not unfrequently eats him? Nay, worse
than this, what can be said for the male Rotifer,
the male Barnacle, the male Lernæa-gentlemen
who cannot even boast of a perfect digestive
apparatus, sometimes not of a digestive organ
at all? Nor is this meagreness confined to the
digestive system only. In some cases,* as in some
* Compare GEGENBAUR: Grundzüge der vergleichende Ana-
tomie, 1859, pp. 229 und 269; also LEYDIG über Hydatina senta,
in Müller's Archiv, 1857, p. 411.
58
STUDIES IN ANIMAL LIFE.
male Rotifers, the usual organs of sense and
locomotion are wanting; and in a parasitic
Lernæa, the degradation is moral as well as
physical: the female lives in the gills of a fish,
sucking its juices, and the ignoble husband lives
as a parasite upon her!
But this digression is becoming humiliating,
and meanwhile our hands are getting benumbed
with cold. In spite of that, I hold the jar up
to the light, and make a background of my fore-
fingers, to throw into relief some of the trans-
Fig. 11.

VOLVOX GLOBATOR, with eight volvoces enclosed (Magnified).
parent animals.
Look at those light green
crystal spheres sailing along with slow revolv-
STUDIES IN ANIMAL LIFE.
59
ing motion, like planets revolving through space,
except that their orbits are more eccentric. Each
of these spheres is a Volvox globator. Under
the microscope it looks like a crystalline sphere,
studded with bright green specs, from each of
which arise two cilia (hairs), serving as oars to
row the animal through the water. The specs
are united by a delicate network, which is not
always visible, however. Inside this sphere is
a fluid, in which several dark-green smaller
spheres are seen revolving, as the parent-sphere
revolved in the water. Press this Volvox gently
under your compressorium, or between the two
pieces of glass, and you will see these internal
spheres, when duly magnified, disclose them-
selves as identical with their parent; and in-
side them, smaller Volvoces are seen. This is
one of the many illustrations of Life within
Life, of which something was said in the last
chapter.
Nor is this all. Those bright green specs
which stud the surface, if examined with high
powers, will turn out to be not specs, but
60
STUDIES IN ANIMAL LIFE.
animals,* and as Ehrenberg believes (though
the belief is little shared), highly organized
animals, possessing a mouth, many stomachs,
and an eye. It is right to add that not only
are microscopists at variance with Ehrenberg on
the supposed organization of these specs, but
the majority deny that the Volvox itself is an
animal. Von Siebold in Germany, and Pro-
fessor George Busk and Professor Williamson in
England, have argued with so much force against
the animal nature of the Volvox, which they call
a plant, that in most modern works you will
find this opinion adopted. But the latest of
the eminent authorities on the subject of Infu-
soria, in his magnificent work just published,
returns to the old idea that the Volvox is an
animal after all, although of very simple organi-
zation.†
*To avoid the equivoque of calling the parts of an animal,
which are capable of independent existence, by the same term as
the whole mass, we may adopt HUXLEY's suggestion, and call
all such individual parts zöoids, instead of animals. DUGE
suggested zöonites in the same sense.-Sur la Conformité
Organique, p. 13.
† STEIN: Der Organismus der Infusionsthiere, 1859, pp. 36-38.
STUDIES IN ANIMAL LIFE.
61
The dispute may perhaps excite your surprise.
You are perplexed at the idea of a plant (if
plant it be) moving about, swimming with all
the vigour and dexterity of an animal, and swim-
ming by means of animal organs, the cilia. But
this difficulty is one of our own creation. We
first employ the word Plant to designate a vast
group of objects which have no powers of loco-
motion, and then ask, with triumph, How can
a plant move? But we have only to enlarge
our knowledge of plant-life to see that loco-
motion is not absolutely excluded from it
; for
many of the simpler plants-Confervæ and Algæ
-can, and do, move spontaneously in the early
stages of their existence: they escape from their
parents as free swimming rovers, and do not
settle into solid and sober respectability till
later in life. In their roving condition they
are called, improperly enough, "zoospores,
and once gave rise to the opinion that they
were animals in infancy, and became degraded
* Zoospores, from zoon, an animal, and sporos, a seed.
62
STUDIES IN ANIMAL LIFE.
""
into plants as their growth went on. But loco-
motion is no true mark of animal-nature, neither
is fixture to one spot the true mark of plant-
nature. Many animals (Polypes, Polyzoa, Bar-
nacles, Mussels, &c.), after passing a vagabond
youth, ´ settle once and for ever in maturer
age, and then become as fixed as plants. Nay,
human animals not unfrequently exhibit a some-
what similar metempsychosis, and make up for
the fitful capriciousness of wandering youth, by
the steady severity of their application to busi-
ness, when width of waistcoat and smoothness
of cranium suggest a sense of their responsi-
bilities.
Whether this loss of locomotion is to be
regarded as a retrogression on the part of the
plant, or animal, which becomes fixed, may be
questioned; but there are curious indications
of positive retrogression from a higher standard
in the metamorphoses of some animals. Thus
the beautiful marine worm, Terebella, which
secretes a tube for itself, and lives in it, fixed
to the rock, or oyster-shell, has in early life a
STUDIES IN ANIMAL LIFE.
63
distinct head, eyes, and feelers; but in growing
to maturity, it loses all trace of head, eyes,
and even of feelers, unless the beautiful tuft of
streaming threads which it waves in the water
be considered as replacing the feelers. There
are the Barnacles, too, which in the first stage
of their existence have three pairs of legs, a
very simple single eye, and a mouth furnished
with a proboscis. In the second stage they have
six pairs of legs, two compound eyes, complex
in structure, two feelers, but no mouth. In the
third, or final stage, their legs are transformed
into prehensile organs, and they have recovered
a mouth, but have lost their feelers, and their
two complex eyes are degraded to a single and
very simple eye-spot.
But to break up these digressions, let us try
a sweep with our net. We skim it along the
surface, and draw up a quantity of duckweed,
dead leaves, bits of stick, and masses of green
thread, of great fineness, called Conferva by
botanists. The water runs away, and we turn
over the mass. Here is a fine water-beetle,
64
STUDIES IN ANIMAL LIFE.
Dytiscus, and a larva of the same beetle, called
the "Water-tiger," from its ferocity (Fig. 12).
Fig. 12.


WATER BEETLE and its larva.
You would hardly suspect that the slim, big-
headed, long-tailed Water-tiger would grow into
the squat, small-headed, tailless beetle: nor
would you imagine that this Water-tiger would
be so "high fantastical" as to breathe by his
tail. Yet he does both, as you will find if you
watch him in your aquarium.
Continuing our search, we light upon the fat,
sluggish, ungraceful larva of the graceful and
brilliant Dragon-fly, the falcon of insects (Fig. 13).
He is useful for dissection, so pop him in. Among
STUDIES IN ANIMAL LIFE.
65
the dead leaves you perceive several small leeches,
and flat oval Planaria, white and brown; and

Fig. 13.
A
B

DRAGON-FLY LARVÆ.
A ordinary aspect; B with the huge nipper-like jaw extended.
here also is a jelly-like mass, of pale yellow
colour, which we know to be a mass of eggs
deposited by some shell-fish; and as there are
few objects of greater interest than an egg in
course of development, we pop the mass in.
Here (Fig. 14) are two molluscs, Limnæus and
5
66
STUDIES IN ANIMAL LIFE.
Planorbis, one of which is probably the parent
of those eggs.
And here is one which lays no.

A
Fig. 14.

B
A LIMNÆUS STAGNALIS, or water snail.
B PLANORBIS.
Fig. 15.

PALUDINA VIVIPARA.
eggs, but brings forth its young alive it is the
Paludina vivipara (Fig. 15), of which we learned
some interesting details last month.
Scattered
STUDIES IN ANIMAL LIFE.
67
over the surface of the net and dead leaves, are
little dabs of dirty-looking jelly-some of them,
instead of the dirty hue, are almost blood-red.
Experience makes me aware that these dirty dabs
are certainly Polypes—the Hydra fusca, of syste-
matists. I can't tell how it is I know them,
nor how you may know them again. The power
of recognition must be acquired by familiarity:
and it is because men can't begin with fami-
liarity, and can't recognize these Polypes without
it, that so few persons really ever see them.
But the familiarity may be acquired by a very
simple method. Make it a rule to pop every un-
known object into your wide-mouthed phial. In
the water it will probably at once reveal its nature:
if it be a Polype, it will expand its tentacles; if
not, you can identify it at leisure on reaching
home, by the aid of pictures and descriptions.
See, as I drop one of these into the water, it
at once assumes the well-known shape of the
Polype. And now we will see what these blood-
red dabs may be; in spite of their unusual colour,
I cannot help suspecting them to be Polypes also.
Give me the camel-hair brush. Gently the dab
5-2
68
STUDIES IN ANIMAL LIFE.
is removed, and transferred to the phial. Shade
of Trembley! it is a Polype.
*
Is it possible that this discovery leaves you
imperturbable, even when I assure you it is of a
species hitherto undescribed in text-books? Now,
don't be provokingly indifferent! rouse yourself
to a little enthusiasm, and prove that you have
something of the naturalist in you by delighting
in the detection of a new species. "You didn't
know that it was new?" That explains your
calmness. There must be a basis of knowledge
before wonder can be felt-wonder being, as Bacon
says, "broken knowledge." Learn, then, that
hitherto only three species of fresh-water Polypes
have been described: Hydra viridis, hydra fusca,
and Hydra grisea. We have now a fourth to
swell the list; we will christen it Hydra rubra,
and be as modest in our glory as we can.
If any
one puts it to us, whether we seriously attach
importance to such trivialities as specific distinc-
* TREMBLEY in his admirable work, Mémoires pour servir
à l'histoire d'une genre de Polypes d'eau douce, 1744, furnished
science with the fullest and most accurate account of fresh-water
Polypes; but it is a mistake to suppose that he was the original
discoverer of this genus: old LEUWENHOEK had been before him.
STUDIES IN ANIMAL LIFE.
69
tions resting solely upon colour, or size, we can
look profound, you know, and repudiate the
charge. But this is a public and official attitude.
In private, we can despise the distinctions esta-
blished by others, but keep a corner of favouritism
for our own.*
I remember once showing a bottle containing
Polypes to a philosopher: he beheld them with
great calmness. They appeared to him as insig-
nificant as so many stems of duckweed; and lest
you should be equally indifferent, I will at once
inform you that these creatures will interest you
as much as any that can be found in ponds, if
you take the trouble of studying them. They
can be cut into many pieces, and each piece will
grow into a perfect Polype; they may be pricked,
or irritated, and the irritated spot will bud a
young Polype, as a plant buds; they may be
* The editors of the Annals of Natural History append a note
to the account I sent them of this new Polype, from which it
appears that Dr. Gray found this very species, and apparently in
the same spot, nearly thirty years ago. But the latest work of
authority, VAN DER HOEVEN's Handbook of Zoology, only
enumerates the three species. Sce Additional Note at the end of
the chapter, p. 73.
70
STUDIES IN ANIMAL LIFE.
turned inside out, and their skin will become a
stomach, their stomach a skin. They have acute
sensibility to light (towards which they always
move), and to the slightest touch; yet not a
trace of a nervous tissue is to be found in them.
They have powers of motion and locomotion, yet
their muscles are simply a network of large con-
tractile cells. If the water in which they are
kept be not very pure, they will be found infested
with parasites; and quite recently I have noticed
an animal, or vegetal, parasite-I know not which
-forming an elegant sort of fringe to the ten-
tacles clusters of skittle-shaped bodies, too
entirely transparent for any structure whatever
to be made out, in active agitation, like leaves
fluttering on a twig. Some day or other we may
have occasion to treat of the Polypes in detail,
and to narrate the amusing story of their dis-
covery; but what has already been said will
serve to sharpen your attention and awaken some
curiosity in them.
Again and again the net sweeps among the
weed, or dredges the bottom of the pond, bring-
STUDIES IN ANIMAL LIFE.
71
ing up mud, stones, sticks, with a fish, worms,
molluscs, and tritons. The fish we must secure,
for it is a stickleback-a pretty and interesting
inhabitant of an aquarium, on account of its
nest-building propensities. We are surprised at
a fish building a nest, and caring for its young,
like the tenderest of birds (and there are two
other fishes, the Goramy and the Hassar, which
have this instinct); but why not a fish as well
as a bird? The cat-fish swims about in com-
pany with her young, like a proud hen with her
chickens; and the sun-fish hovers for weeks
over her eggs, protecting them against danger.
The wind is so piercing, and my fingers are
so benumbed, I can scarcely hold the brush.
Moreover, continual stooping over the net makes
the muscles ache unpleasantly, and suggests that
each cast shall be the final one. But somehow
I have made this resolution and broken it twenty
times: either the cast has been unsuccessful, and
one is provoked to try again, or it is so suc-
cessful that, as l'appétit vient en mangeant, one
is seduced again. Very unintelligible this would
72
STUDIES IN ANIMAL LIFE.
be to the passers-by, who generally cast con-
temptuous glances at us, when they find we are
not fishing, but are only removing Nothings into
a glass jar.
One day an Irish labourer stopped and asked
me if I were fishing for salmon. I quietly
answered, "Yes." He drew near. I continued
turning over the weed, occasionally dropping an
invisible thing into the water. At last, a large
yellow-bellied Triton was dropped in. He begged
to see it; and seeing at the same time how alive
the water was with tiny animals, became curious,
and asked many questions. I went on with my
work; his interest and curiosity increased; his
questions multiplied; he volunteered assistance;
and remained beside me till I prepared to go
away, when he said seriously: "Och! then, and
it's a fine thing to be able to name all God's
creatures." Contempt had given place to reve-
rence; and so it would be with others, could
they check the first rising of scorn at what they
do not understand, and patiently learn what even
a roadside pond has of Nature's wonders.
STUDIES IN ANIMAL LIFE.
73
ADDITIONAL NOTE.
ON THE HYDRA RUBRA.
Had I thrown any zoological amour propre into
the discovery of new species, it would have been
much disturbed when in the following autumn
I found these very Polypes, kept in a vase by
themselves and with weed from a different pond,
gradually losing their red colour, and becoming
indistinguishable from the Hydra fusca. It was
clearly something in the food which gave them
their red tone; and this is why hitherto they have
only been found in the ponds of Wimbledon
common.
The following passage from a former work may
be cited in point: "Apropos of the peculiarity of
colour, I may remark on the great variations
observable in the colour of Anemones, and the
impropriety of making colour the distinguishing
mark of species. Thus, to select a striking
example, Mr. Gosse makes two distinct species
of the orange-disked and orange-tentacled Ane-
mones, naming them Venusta and Aurora; but,
*
74
STUDIES IN ANIMAL LIFE.
as if to prove the indifference of all such charac-
teristics, I brought with me from Tenby an
orange-disked—and only one-which before it
had been home a fortnight, I discovered with
great surprise was changed into an orange-
tentacled-disc and tentacles being of a rich
orange hue, the only traces of white being just
at the tips. If there had been any other speci-
men in the vase I might have doubted, but
having only one in company with a white Daisy
and a smooth Anemone, there was no avoiding
the conclusion.
"I have had an Authea with brilliant green
tentacles turn to a pale gray in the course of
two days and back again to green; and a Wey-
mouth Anemone turn from pearly white to a soft
reddish brown. In fact, the changes of colour,
except in the Crassicornis, which appears to
retain its hues with tolerable constancy, are too
frequent to admit of colour forming a specific
character."*
* Seaside Studies, 2nd edition, p. 150.
STUDIES IN ANIMAL LIFE.
75
CHAPTER III.
A garden wall, and its traces of past life-Not a breath perishes
-A bit of dry moss and its inhabitants-The "Wheel-
bearers "-Resuscitation of Rotifers: drowned into life-
Current belief that animals can be revived after complete
desiccation-Experiments contradicting the belief-Spallan-
zani's testimony-Value of biology as a means of culture-
Classification of animals: the five great types-Criticism of
Cuvier's arrangement.
""
PLEASANT, both to eye and mind, is an old garden
wall, dark with age, gray with lichens, green with
mosses of beautiful hues and fairy elegance of
form: a wall shutting in some sequestered home,
far from the din of murmurous cities vast:
a home where, as we fondly, foolishly think, Life
must needs throb placidly, and all its tragedies
and pettinesses be unknown. As we pass along-
side this wall, the sight of the overhanging
branches suggests an image of some charming
nook or our thoughts wander about the wall
76
STUDIES IN ANIMAL LIFE.
itself, calling up the years during which it has
been warmed by the sun, chilled by the night airs
and the dews, and dashed against by the wild
winds of March: all of which have made it quite
another wall from what it was when the trowel
first settled its bricks. The old wall has a past,
a life, a story; as Wordsworth finely says of the
mountain, it is "familiar with forgotten years.'
Not only are there obvious traces of age in
the crumbling mortar and the battered brick,
but there are traces, not obvious, except to the
inner eye, left by every ray of light, every rain-
drop, every gust. Nothing perishes. In the
wondrous metamorphosis momently going on
everywhere in the universe, there is change, but
no loss.
Lest you should imagine this to be poetry, and
not science, I will touch on the evidence that
every beam of light, or every breath of air, which
falls upon an object, permanently affects it. In
photography we see the effect of light very
strikingly exhibited; but perhaps you will object
that this proves nothing more than that light acts
STUDIES IN ANIMAL LIFE,
77
upon an iodized surface. Yet in truth light acts
upon, and more or less alters, the structure of
every object on which it falls. Nor is this all. If
a wafer be laid on a surface of polished metal,
which is then breathed upon, and if, when the
moisture of the breath has evaporated, the wafer
be shaken off, we shall find that the whole polished
surface is not as it was before, although our senses
can detect no difference; for if we breath again
upon it, the surface will be moist everywhere
except on the spot previously sheltered by the
wafer, which will now appear as a
"spectral
image" on the surface. Again and again we
breath, and the moisture evaporates, but still the
spectral wafer reappears.
This experiment succeeds even after a lapse of
many months, if the metal be carefully put aside
where its surface cannot be disturbed. If a sheet
of paper, on which a key has been laid, be exposed
for some minutes to the sunshine, and then
instantaneously viewed in the dark, the key being
removed, a fading spectre of the key will be
visible. Let this paper be put aside for many
7.8
STUDIES IN ANIMAL LIFE.
months where nothing can disturb it, and then
in darkness be laid on a plate of hot metal, the
spectre of the key will again appear. In the case
of bodies more highly phosphorescent than paper,
the spectres of many different objects which may
have been laid on in succession will, on warming,
emerge in their proper order.*
This is equally true of our bodies, and our
minds. We are involved in the universal meta-
morphosis. Nothing leaves us wholly as it found
us. Every man we meet, every book we read,
every picture or landscape we see, every word or
tone we hear, mingles with our being and modifies
it. There are cases on record of ignorant women,
in states of insanity, uttering Greek and Hebrew
phrases, which in past years they had heard their
masters utter, without of course comprehending
them. These tones had long been forgotten: the
traces were so faint that under ordinary conditions
they were invisible; but the traces were there,
and in the intense light of cerebral excitement
* DRAPER: Human Physiology, p. 228.
STUDIES IN ANIMAL LIFE,
79
1
they started into prominence, just as the spectral
image of the key started into sight on the appli-
cation of heat. It is thus with all the influences
to which we are subjected.
If a garden wall can lead our vagabond thoughts
into such speculations as these, surely it may also
furnish us with matter for our Studies in Animal
Life? Those patches of moss must be colonies.
Suppose we examine them? I pull away a small
bit, which is so dry that the dust crumbles at
a touch; this may be wrapped in a piece of paper
-dirt and all-and carried home. Get the micro-
scope ready, and now attend.
I moisten a fragment of this moss with distilled
water. Any water will do as well, but the use of
distilled water prevents your supposing that the
animals you are about to watch were brought in it,
and were not already in the moss. I now squeeze
the bit between my fingers, and a drop of the
contained water-somewhat turbid with dirt-falls
on the glass slide, which we may now put on the
microscope stage. A rapid survey assures us that
there is no animal visible. The moss is squeezed
80
STUDIES IN ANIMAL LIFE.
again; and this time little yellowish bodies of an
irregular oval are noticeable among the particles
of dust and moss. Watch one of these, and pre-
sently you will observe a slow bulging at one end,
and then a bulging at the other end. The oval
has elongated itself into a form not unlike that
of a fat caterpillar, except that there is a tapering
at one end. Now a forked tail is visible; this
fixes on to the glass, while the body sways to
and fro. Now the head is drawn in-as if it were
swallowed-and, suddenly, in its place are un-
folded two broad membranes, having each a circle
of waving cilia. The lifeless oval has become
a living animal! You have assisted at a resusci-
tation, not from death by drowning, but by
drying the animal has been drowned into life!
The unfolded membranes, with their cilia, have so
much the appearance of wheels that the name of
"Wheel-bearer" (Rotifera) or "Wheel Animal-
cule" has been given to the animal.
:
The Rotifera (also—and more correctly-called
Rotatoria) form an interesting study. Let us
glance at their organization :-
STUDIES IN ANIMAL LIFE.
81
A
b
Fig. 16.

B

C
e
e
h
g
h
g
k
k
ROTIFER VULGARIS. A, with the wheels drawn in (at c). B
with wheels expanded; b, eye spots; e, jaws and teeth; ƒ
alimentary canal; g, embryo; h, embryo further developed ;
i, water-vascular system; k, vent.
There are many different kinds of Rotifers,
varying very materially in size and shape; the
males, as was stated in the last chapter, being
more imperfectly organized than the females.
They may be seen either swimming rapidly
through the water by means of the vibratile cilia
6
82
STUDIES IN ANIMAL LIFE.
called "wheels," because the optical effect is very
much that of a toothed-wheel; or crawling along
the side of the glass, fastening to it by the head,
and then curving the body till the tail is brought
up to the spot, which is then fastened on by the
tail, and the head is set free. They may also be
seen fastened to a weed, or the glass, by the
tail, the body waving to and fro, or thrusting
itself straight out, and setting the wheels in
active motion. In this attitude the aspect of the
jaws is very striking. Leuwenhoek mistook it
for the pulsation of a heart, which its incessant
rhythm much resembles. The tail, and the upper
part of the body, have a singular power of being
drawn out, or drawn in, like the tube of a
telescope. There is sometimes a shell, or cara-
pace, but often the body is covered only with a
smooth firm skin, which, however, presents
decided indications of being segmented.
The first person who described these Rotifers
was the excellent old Leuwenhoek; and his
*
* LEUWENHOEK: Select Works, ii. p. 210. His figures, how-
ever, are very incorrect.
STUDIES IN ANIMAL LIFE.
83
animals were got from the gutter of a house-top.
Since then, they have been minutely studied, and
have been showed to be, not Infusoria, as Ehren-
berg imagined, but Crustacea. Your attention is
requested to the one point which has most
contributed to the celebrity of these creatures
their power of resuscitation. Leuwenhoek
described-what you have just witnessed, namely
-the slow resuscitation of the animal (which
seemed as dry as dust, and might have been
blown about like any particle of dust,) directly a
little moisture was brought to it. Spallanzani
startled the world with the announcement that
this process of drying and moistening-of killing
and reviving-could be repeated fifteen times in
succession; so that the Rotifer, whose natural
term of life is about eighteen days, might, it was
said, be dried and kept for years, and at any
time revived by moisture. That which seems now
no better than a grain of dust will suddenly
* See LEYDIG: Ueber den Bau und die systematiche Stellung
der Räderthiere, in SIEBOLD und KÖLLIKER's Zeitschrift, vi.,
and Ueber Hydatina Senta, in MÜLLER'S Archiv: 1857.
6—2
84
STUDIES IN ANIMAL LIFE.
awaken to the energetic life of a complex organism,
and may again be made as dust by evaporation of
the water.
This is very marvellous: so marvellous that a
mind, trained in the cultivated caution of science,
will demand the evidence on which it is based.
Two months ago I should have dismissed the
doubt with the assurance that the evidence was
ample and rigorous, and the fact indisputable.
For not only had the fact been confirmed by the
united experience of several investigators: it had
stood the test of very severe experiment. Thus
in 1842, M. Doyère published experiments which
seemed to place it beyond scepticism. Under
the air-pump he set some moss, together with
vessels containing sculphuric acid, which would
absorb every trace of moisure. After leaving the
moss thus for a week, he removed it into an oven,
the temperature of which was raised to 300°
Fahrenheit. Yet even this treatment did not
prevent the animals from resuscitating when
water was added.
In presence of testimony like this, doubt will
STUDIES IN ANIMAL LIFE.
85
seem next to impossible. Nevertheless, my own
experiments leave me no choice but to doubt.
Not having witnessed M. Doyère's experiment,
I am not prepared to say wherein its fallacy lies;
but that there is a fallacy, seems to me probable.
In M. Pouchet's recent work* I first read a distinct
denial of the pretended resuscitation of the
Rotifers; this denial was the more startling to
me, because I had myself often witnessed the
reawakening of these dried animals. Never-
theless, whenever a doubt is fairly started, we
have not done justice to it until we have brought
it to the test of experiment; accordingly I tested
this, and quickly came upon what seemed to me
the source of the general misconception. Day
after day experiments were repeated, varied, and
controlled, and with results so unvarying that
hesitation vanished; and as some of these experi-
ments are of extreme simplicity, you may verify
what I say with little trouble. Squeeze a drop
of water from the moss, taking care that there is
* POUCHET: Hétérogénie, ou Traité de la Génération Spon-
tanée, 1859, p. 453.
86
STUDIES IN ANIMAL LIFE.
scarcely any dirt in it; and, having ascertained
that it contains Rotifers, or Tardigrades,* alive and
moving, place the glass-slide under a bell-glass,
to shield it from currents of air, and there allow
the water to evaporate slowly, but completely,
by means of chloride of calcium, or sulphuric
acid, placed under the bell-glass; or what is
still simpler, place a slide with the live animals
on the mantelpiece when a fire is burning in the
grate. If on the day following you examine this
perfectly dry glass, you will see the contracted
bodies of the Rotifers, presenting the aspect of
yellowish oval bodies; but attempt to resuscitate
them by the addition of a little fresh water, and
you will find that they do not revive, as they
revived when dried in the moss: they sometimes
swell a little, and elongate themselves, and you
imagine this is a commencement of resuscitation;
*The Tardigrade, or microscopic Sloth, belongs to the order
of Arachnida, and is occasionally found in moss, stagnant ponds,
&c. I have only met with four specimens in all my investiga-
tions, and they were all found in moss. SPALLANZANI described
and figured it (very badly), and M. DOYERE has given a fuller
description in the Annales des Sciences, 2nd series, vols. xiv.,
xvii. and xviii.
STUDIES IN ANIMAL LIFE.
87
but continue watching for two or three days, and
you will find it goes no further. Never do these
oval bodies become active crawling Rotifers; never
do they expand their wheels, and set the œsophagus
at work. No: the Rotifer once dried is dead, and
dead for ever.
But if, like a cautious experimenter, you vary
and control the experiment, and beside the glass-
slide place a watch-glass containing Rotifers with
dirt, or moss, you will find that the addition of
water to the contents of the watch-glass will often
(not always) revive the animals. What you cannot
effect on a glass-slide without dirt, or with very
little, you easily effect in a watch-glass with dirt,
or moss; and if you give due attention you will
find that in each case the result depends upon
the quantity of the dirt. And this leads to a
clear understanding of the whole mystery; this
reconciles the conflicting statements. The reason
why Rotifers ever revive is, because they have
not been dried-they have not lost by evapora-
tion that small quantity of water which forms
an integral constituent of their tissues; and it is
88
STUDIES IN ANIMAL LIFE.
the presence of dirt, or moss, which prevents
this complete evaporation. No one, I suppose,
believes that the Rotifer actually revives after
once being dead. If it has a power of remain-
ing in a state of suspended animation, like that
of a frozen frog, it can do so only on the condition
that its organism is not destroyed; and destroyed
it would be, if the water were removed from its
tissues; for, strange as it may seem, water is not
an accessory, but a contsituent element of every
tissue; and this cannot be replaced mechanically
-it can only be replaced by vital processee.
Every one who has made microscopic prepara-
tions must be aware that when once a tissue is
desiccated, it is spoiled: it will not recover its
form and properties on the application of water ;
because the water was not originally worked into
the web by a mere process of imbibition-like
water in a sponge-but by a molecular process
of assimilation, like albumen in a muscle.
Therefore, I say, that desiccation is necessarily
death; and the Rotifer which revives cannot have
been desiccated. This being granted, we have
STUDIES IN ANIMAL LIFE.
89
only to ask, What prevents the Rotifer from
becoming completely dried? Experiment shows
that it is the presence of dirt, or moss, which
does this. The whole marvel of the Rotifer's
resuscitation, therefore, amounts to this:-that
if the water in which it lives be evaporated, the
animal passes into a state of suspended animation,
and remains so, as long as its own water is pro-
tected from evaporation.
I am aware that this is not easily to be re-
conciled with M. Doyère's experiments, since the
application of a temperature so high as 300° Fahr.
(nearly a hundred degrees above boiling water)
must, one would imagine, have completely desic-
cated the animals, in spite of any amount of
protecting dirt. It is possible that M. Doyère
may have mistaken that previously-noted swelling-
up of the bodies, on the application of water, for
a return to vital activity. If not, I am at a loss
to explain the contradiction; for certainly in my
experience a much more moderate desiccation-
namely, that obtained by simple evaporation over
a mantelpiece, or under a large bell-glass—always
90
STUDIES IN ANIMAL LIFE.
destroyed the animals, if little or no dirt were
present.
The subject has recently been brought before
the French Academy of Sciences by M. Davaine,
whose experiments* lead him to the conclusion
that those Rotifers which habitually live in ponds
will not revive after desiccation: whereas those
which live in moss always do so. I believe the
explanation to be this: the Rotifers living in ponds
are dried without any protecting dirt, or moss,
and that is the reason they do not revive.
After having satisfied myself on this point, I
did what perhaps would have saved me some
trouble if thought of before. I took down Spallan-
zani, and read his account of his celebrated ex-
periments. To my surprise and satisfaction, it
appeared that he had accurately observed the same
facts, but curiously missed their real significance.
Nothing can be plainer than the following passage:
"But there is one condition indispensable to the
resurrection of wheel-animals: it is absolutely
necessary that there should be a certain quantity
* DAVAINE in Annales des Sciences Naturelles, 1858, x. p. 335.
STUDIES IN ANIMAL LIFE.
91
One
of sand; without it they will not revive.
day I had two wheel-animals traversing a drop
of water about to evaporate, which contained very
little sand. Three quarters of an hour after evapo-
ration they were dry and motionless. I moistened
them with water to revive them; but in vain,
notwithstanding that they were immersed in water
many hours. Their members swelled to thrice
the original size, but they remained motionless.
To ascertain whether the fact was accidental, I
spread a portion of sand, containing animals, on
a glass slide, and waited till it became dry in
order to wet it anew. The sand was carelessly
scattered on the glass, so as to be a thin covering
on some parts, and on others in a very small
quantity: here the animal did not revive: but
all that were in those parts with abundance of sand
revived."*
He further says that if sand be spread
out in considerable quantites in some places, much
less in others, and very little in the rest, on
moistening it the revived animals will be numerous
* SPALLANZANI: Tracts on the Natural History of Animals
and Vegetables: Translated by Dalyell, ii. p. 129.
92
STUDIES IN ANIMAL LIFE.
in the first, less numerous in the second, and none
at all in the third.
It is not a little remarkable that observations so
precise as these should have for many years passed
unregarded, and not led to the true explanation of
the mystery. Perhaps an inherent love of the
marvellous made men greedily accept the idea of
resuscitation, and indisposed them to attempt an
explanation of it. Spallanzani's own attempt is
certainly not felicitous. He supposes that the
dust prevents the lacerating influence of the air
from irritating and injuring the animals. And
this explanation is accepted by his Translator.
[Since the foregoing remarks were in type,
M. Gavarret has published (Annales des Sciences
Naturelles, 1859, xi. p. 315) the account of his
experiments on Rotifers and Tardigrades, in which
he found that after subjecting the moss to a desic-
cation the most complete according to our present
means, the animals revived after twenty-four
hours' immersion of the moss in water. This
result seems flatly to contradict the result I
arrived at; but only seems to contradict it, for
STUDIES IN ANIMAL LIFE.
93
in my experiments the animals, not the moss,
were subjected to desiccation. Nevertheless, I
confess that my confidence was shaken by experi-
ments so precise, and performed by so distin-
guished an investigator, and I once more resumed
the experiments, feeling persuaded that the detec-
tion of the fallacy, wherever it might be, would be
well worth the trouble. The results of these con-
trolling experiments are all I can find room for
here :-Whenever the animals were completely
separated from the dirt, they perished; in two
cases there was a very little dirt-a mere film, so
to speak-in the watch-glass, and glass-cell, and
this, slight as it was, sufficed to protect two out
of eight, and three out of ten Rotifers, which
revived on the second day; the others did not
revive even on the third day after their immersion.
In one instance, a thin covering-glass was placed
over the water on the slide, and the evaporation of the
water seemed complete, yet this glass-cover sufficed
to protect a Rotifer, which revived in three hours.
If we compare these results with those obtained
by M. Davaine, we can scarcely avoid the conclu-
94
STUDIES IN ANIMAL LIFE.
sion that it is only when the desiccation of the
Rotifers is prevented by the presence of a small
quantity of moss, or of dirt-between the particles
of which they find shelter—that they revive on the
application of water. And even in the severe
experiments of M. Doyère and M. Gavarret, some
of the animals must have been thus protected; and
I call particular attention to the fact that, although
some animals revived, others always perished.
But if the organization of the Rotifer, or Tardi-
grade, is such that it can withstand desiccation-if
it only needs the fresh applications of moisture to
restore its activity-all, or almost all, the animals
experimented on ought to revive; and the fact that
only some revive leads us to suspect that these
have not been desiccated-a suspicion which is
warranted by direct experiments. I believe, then,
that the discrepancy amounts to this: investigators
who have desiccated the moss containing animals,
find some of the animals revive on the application
of moisture; but those who desiccate the animals
themselves, will find no instances of revival.]*
* See Additional Note at the end of the chapter, p. 110.
STUDIES IN ANIMAL LIFE.
95
The time spent on these Rotifers will not have
been misspent if it has taught us the necessity of
caution in all experimental inquiries. Although
Experiment is valuable-nay, indispensable—as a
means of interrogating Nature, it is constantly
liable to mislead us into the idea that we have
rightly interrogated, and rightly interpreted the
replies; and this danger arises from the com-
plexity of the cases with which we are dealing, and
our proneness to overlook, or disregard, some
seemingly trifling condition-a trifle which may
turn out of the utmost importance. The one
reason why the study of Science is valuable as a
means of culture, over and above its own immediate
objects, is that in it the mind learns to submit to
realities, instead of thrusting its figments in the
place of realities-endeavours to ascertain accu-
rately what the order of Nature is, and not what it
ought to be, or might be. The one reason why, of
all sciences, Biology is pre-eminent as a means of
culture is, that owing to the great complexity of
all the cases it investigates, it familiarizes the mind
with the necessity of attending to all the conditions,
96
STUDIES IN ANIMAL LIFE.
and it thus keeps the mind alert. It cultivates
caution, which, considering the tendency there is in
men to "anticipate Nature," is a mental tonic of
inestimable worth. I am far from asserting that
biologists are more accurate reasoners than other
men; indeed, the mass of crude hypothesis which
passes unchallenged by them, is against such an
idea. But whether its advantages be used or
neglected, the truth nevertheless is, that Biology,
from the complexity of its problems, and the
necessity of incessant verification of its details,
offers greater advantages for culture than any other
branch of science.
I have once or twice mentioned the words Mol-
lusc and Crustacean, to which the reader unfa-
miliar with the language of Natural History
will have attached but vague ideas; and although
I wanted to explain these, and convey a distinct
conception of the general facts of Classification,
it would have then been too great an interrup-
tion. So I will here make an opportunity, and
finish the chapter with an indication of the five
Types, or plans of structure, under one of which
STUDIES IN ANIMAL LIFE.
97
every animal is classed. Without being versed in
science, you discern at once whether the book before
you is mathematical, physical, chemical, botanical,
or physiological. In like manner, without being
versed in Natural History, you ought to know whe-
ther the animal before you belongs to the Verte-
brata, Mollusca, Articulata, Radiata, or Protozoa.
A glance at the contents of our glass vases will
yield us samples of each of these five divisions of
the animal kingdom. We begin with this Triton.
Fig. 17.

MALE TRITON, or WATER-NEWT.
7
98
STUDIES IN ANIMAL LIFE.
It is a representative of the VERTEBRATE division,
or sub-kingdom. You have merely to remember
that it possesses a backbone and an internal
skeleton, and you will at once recognize the
cardinal character which makes this Triton range
under the same general head as men, elephants,
whales, birds, reptiles, or fishes. All these, in
spite of their manifold differences, have this
one character in common :- they are all back-
boned; they have all an internal skeleton;
they are all formed according to one general
type.
In all vertebrate animals the skeleton is found
to be identical in plan. Every bone in the body
of a triton has its corresponding bone in the body
of a man, or of a mouse; and every bone preserves
the same connection with other bones, no matter
how unlike may be the various limbs in which
we detect its presence. Thus, widely as the arm
of a man differs from the fin of a whale, or the
wing of a bird, or the wing of a bat, or the leg
of a horse, the same number of bones, and the
same connections of the bones, are found in each.
STUDIES IN ANIMAL LIFE.
99
A fin is one modified form of the typical limb;
an arm is another; a wing another.
That which is true of the limbs, is also true
of all the organs; and it is on this ground that
we speak of the vertebrate type. From fish to
man one common plan of structure prevails; and
the presence of a backbone is the index by which
to recognize this plan.
The Triton has been wriggling grotesquely in
our grasp while we have made him our text, and,
now he is restored to his vase, plunges to the
bottom with great satisfaction at his escape. This
water-snail, crawling slowly up the side of the
vase, and cleaning it of the green growth of
microscopic plants, which he devours, shall be
our representative of the second great division-
the MOLLUSCA.
I cannot suggest any obvious character so dis-
tinctive as a backbone, by which the word Mollusc
may at once call up an idea of the type which
prevails in the group. It won't do to say "shell-
fish," because many molluscs have no shells, and
many animals which have shells are not molluscs.
7-2
100
STUDIES IN ANIMAL LIFE.
The name was originally bestowed on account of
the softness of the animals. But they are not
softer than worms, and much less soft than jelly-
fish. You may know that snails and slugs, oysters
and cuttlefish, are molluscs; but if you want some
one character by which the type may be remem-
bered, you must fix on the imperfect symmetry
of the mollusc's organs.
I say imperfect symmetry, because it is an
error, though a common one, to speak of the
mollusc's body not being bilateral—that is to
say, of its not being composed of two symme-
trical halves. A vertebrate animal may be divided
lengthwise, and each half will closely resemble
the other; the backbone forms, as it were, an
axis, on either side of which the organs are dis-
posed; but the mollusc is said to have no such
axis, no such symmetry. I admit the absence of
an axis, but I deny the total absence of symmetry.
Many of its organs are as symmetrical as those
of a vertebrate animal-i. e. the eyes, the feelers,
the jaws—and the gills in Cuttlefish, Eolids, and
Pteropods; while, on the other hand, several
STUDIES IN ANIMAL LIFE.
101
organs in the vertebrate animal are as unsym-
metrical as any of those in the mollusc—such
organs are the liver, spleen, pancreas, stomach,
and intestines.*
As regards bilateral structure, therefore, it is
only a question of degree. The vertebrate animal
is not entirely symmetrical, nor is the mollusc
entirely unsymmetrical. But there is a charac-
teristic disposition of the nervous system peculiar
to molluscs: it neither forms an axis for the body
-as it does in the Vertebrata and Articulata-
nor a centre-as it does in the Radiata-but is
altogether irregular and unsymmetrical.
will be intelligible from the following diagram
of the nervous systems of a Mollusc and an Insect
(Fig. 18), with which that of a Star-fish may be
compared (Fig. 19). Here you perceive how the
nervous centres, and the nerves which issue from
This
* In some cases of monstrosity, these organs are transposed,
the liver being on the left, and the pancreas on the right side.
It was in allusion to a case of this kind, then occupying the
attention of Paris, that MOLIÈRE made his Medecin malgré Lui
describe the heart as on the right side, the liver on the left; on
the mistake being noticed, he replies: Oui, autrefois; mais
nous avons changé tout cela."
""
102
STUDIES IN ANIMAL LIFE.
them, are irregularly disposed in the molluscs, and
symmetrically disposed in the insect.
But the recognition of a mollusc will be easier

Fig. 18.
A
B

NERVOUS SYSTEM OF SEA-HARE (A) and CENTIPEde (B).
when you have learned to distinguish it from
one of the ARTICULATA, forming the third great
division,—the third animal Type. Of these, our
vases present numerous representatives: prawns,
STUDIES IN ANIMAL LIFE.
103
beetles, water-spiders, insect-larvæ, entomostraca,
and worms. There is a very obvious character
by which these may be recognized: they have
all bodies composed of numerous segments, and
their limbs are jointed, and they have mostly an
external skeleton from which their limbs are
developed. Sometimes the segments of their
bodies are numerous, as in the centipede, lobster,
&c.; sometimes several segments are fused to-
gether, as in the crab; and sometimes, as in
worms, they are indicated by slight markings or
depressions of the skin, which give the appear-
ance of little rings, and hence the worms have
been named Annelida, or Annulata, or Annulosa.
In these last-named cases the segmental nature
of the type is detected in the fact that the worms
grow, segment by segment; and also in the fact
that in most of them each segment has its own
nerves, heart, stomach, &c.-each segment is, in
fact, a zöoid.*
Just as we recognize a vertebrate animal by the
* The term zcoid was explaired, rage Co.
104
STUDIES IN ANIMAL LIFE.
*
presence of a backbone and internal skeleton, we
recognize an articulate animal by its jointed
body and external skeleton. In both, the nervous
system forms the axis of the body. The Mollusc,
on the contrary, has no skeleton, internal or ex-
ternal; and its nervous system does not form
an axis. As a rule, both vertebrates and articu-
lates have limbs-although there are exceptions
in serpents, fishes, and worms. The Molluscs
have no limbs. Backboned,-jointed,—and non-
jointed, therefore, are the three leading character-
istics of the three types.
Let us now glance at the fourth division-
the RADIATA, so called because of the disposition
of the organs round a centre, which is the mouth.
Our fresh-water vases afford us only one repre-
sentative of this type-the Hydra, or fresh-water
Polype, whose capture was recorded in the last
chapter. Is it not strange that while all the
Radiata are aquatic, not a single terrestrial repre-
sentative having been discovered, only one should
*In the cuttlefish there is the commencement of an internal
skeleton in the cartilage-plates protecting the brain.
STUDIES IN ANIMAL LIFE.
105
be found in fresh water? Think of the richness
of the seas, with their hosts of Polypes, Actiniæ,
Jelly-fish, Star-fishes, Sea-urchins, Sea-pens,
(Pennatula), Lily-stars (Comatula), and Sea-
cucumbers (Holothuria), and then compare the
poverty of rivers, lakes, and ponds, reduced to
their single representative, the Hydra. The
radiate structure may best be exhibited by this
diagram of the nervous system of the Star-fish.*
Fig. 19.

NERVOUS SYSTEM OF STAR-FISH.
Cuvier, to whom we owe this classification of
the animal kingdom into four great divisions,
* It is right to add, that there are serious doubts entertained
respecting the claim of a star-fish to the possession of a nervous
system at all; but the radiate structure of the body is represented
in the diagram; as it also is, very clearly, in a Sea-anemone.
106
STUDIES IN ANIMAL LIFE.
would have been the first to recognize the chaotic
condition in which he left this last division, and
would have acquiesced in the separation of the
PROTOZOA, which has since been made. This
fifth division includes many of the microscopic
animals known as Infusoria; and receives its
name from the idea that these simplest of all
animals represent, as it were, the beginnings of
life.*
But Cuvier's arrangement is open to a more
serious objection. The state of science in his day
excused the imperfection of classing the Infusoria
and parasites under the Radiata; but it was
owing, I conceive, to an unphilosophical view of
morphology, that he placed the molluscs next to
the Vertebrata, instead of placing the Articulata
in that position. He was secretly determined by
the desire to show that there are four very distinct
types, or plans of structure, which cannot by any
transitions be brought under one law of develop-
ment. Lamarck and Geoffrey St. Hilaire main-
tained the doctrine of unity of composition
* Protozoa, from proton, first, and zoon, animal.
STUDIES IN ANIMAL LIFE.
107 -
throughout the animal kingdom;-in other words,
that all the varieties of animal forms were pro-
duced by successive modifications: and several of
the German naturalists maintained that the verte-
brata in their embryonic stages passed through
forms which were permanent in the lower animals.
This idea Cuvier always opposed. He held that
the four types were altogether distinct; and by
his arrangement of them, their distinctness cer-
tainly appears much greater than would be the
case on another arrangement.
But without discussing this question here, it
is enough to point out the fact of the enormous
superiority in intelligence, in sociality, and in
complexity of animal functions, exhibited by insects
and spiders, when compared with the highest of
the molluscs, to justify the removal of the mollusca,
and the elevation of the articulata to the second
place in the animal hierarchy.
Nor is this all. If we divide animals into four
groups, these four naturally dispose themselves
into two larger groups: the first of these, com-
prising Vertebrata and Articulata, is characterized
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STUDIES IN ANIMAL LIFE.
by a nervous axis and a skeleton; the second,
comprising Mollusca and Radiata, is charac-
terized by the absence of both nervous axis and
skeleton. It is obvious that a bee much more
closely resembles a bird, than any mollusc re-
sembles any vertebrate. If there are many and
important differences between the vertebrate and
articulate types, there are also many and impor-
tant resemblances; if the nervous axis is above
the viscera, and forms the dorsal line of the
vertebrate, whereas it is underneath the viscera,
and forms the ventral line in the articulate, it
is, nevertheless, in both, the axis of the body, and
in both it sends off nerves to supply symmetrical
limbs; in both it has similar functions. And
while the articulata thus approach in structure
the vertebrate type, the mollusca are not only
removed from that type by many diversities, but
a number of them have such affinities with the
Radiate type, that it is only in quite recent days
that the whole class of Polyzoa (or Bryozoa, as
they are also called) has been removed from the
Radiata, and ranged under the Mollusca.
STUDIES IN ANIMAL LIFE.
109
To quit this topic, and recur once more to the
five divisions, we have only the broad outlines of
the picture in Vertebrata, Mollusca, Articulata,
Radiata, and Protozoa; but this is a good begin-
ning, and we can now proceed to the further
sub-divisions.
Each of these five sub-kingdoms is divided into
Classes; these again into Orders; these into
Families; these into Genera; these in Species;
and these finally into Varieties.
Thus suppose a dwarf-terrier is presented to
us with a request that we should indicate its
various titles in the scheme of classification: we
begin by calling it a vertebrate; we proceed to
assign its Class as the mammalian; its Order is
obviously that of the carnivora; its Family is that
of the fox, wolf, jackal, &c., named Canidæ; its
Genus is, of course, that of Canis; its Species,
terrier; its Variety, dwarf-terrier.
Inasmuch as all these denominations are the
expressions of scientific research, and not at all
arbitrary or fanciful, they imply an immense
amount of labour and sagacity in their establish-
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STUDIES IN ANIMAL LIFE.
ment; and when we remember that naturalists
have thus classed upwards of half a million of
distinct species, it becomes an interesting inquiry,
-What has been the guiding principle of this
successful labour? on what basis is so large a
superstructure raised? This question we shall
answer in the next chapter.
ADDITIONAL NOTE.
ON THE RESUSCITATION OF ANIMALS.
This subject, which was being hotly debated
before the French Academy at the time I wrote, has
been kept up on both sides with spirit; but I am
forced to confess that the decision must be given
against the view I have advocated. The Société
de Biologie appointed a commission to examine this
question; the commission, composed of Balbiani,
Berthelot, Broca, Brown Séquard, Camille Dareste,
Guillemin, and Charles Robin, justified its labours
by the masterly Report, drawn up by Paul Broca,
and published in the Mémoires of the Society for
1860, tom. II. pp. 33–139.
STUDIES IN ANIMAL LIFE.
111
It would, of course, occupy far too much space.
here to repeat the experimental evidence on which
this commission bases its conclusion, but the con-
clusion itself may be given in the following trans-
lation:-
"The resistance of Tardigrades and Rotifers to
elevated temperatures appears to increase in pro-
portion to their previous desiccation. Rotifers
will revive after remaining eighty-two days in dry
vacuo, and subsequently placed in a temperature
of 212° Fahr. during thirty minutes. Consequently,
animals which have been desiccated successively
in vacuo, and in a temperature of 212° Fahr.-
that is to say, reduced to the most complete
desiccation possible to be realized under those
conditions and in the present state of science—
can still preserve the property of reviving on the
contact of water.”
This conclusion must, I think, be adopted by
almost every one who attentively considers the
experimental evidence-I, for one, give way. But,
in doing so, I wish very distinctly to state, that
one position on which my argument rested, so far
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STUDIES IN ANIMAL LIFE.
from being shaken by M. Broca's Report, is con-
firmed by the assent of all physiologists. The
position alluded to is, that "desiccation is neces-
sarily death." It was impugned by one of my
correspondents in the following passage, which
contains an interesting fact :-"In Chap. III. of
your Studies, there is a discussion on the subject
of the revival of desiccated animals, which is
summed up at p. 288 by the axiom, that, 'desic-
cation is necessarily death.' From very numerous
experiments, conducted with great care, I am
convinced that this is entirely incorrect. To
avoid the errors mentioned in the paper, I experi-
mented upon creatures of much larger size than
the Rotifera-such as the fresh-water crustaceans,
the Daphne, &c.-creatures where the circulation
and respiration can be observed with ease by the
microscope. I have dried these animals so per-
fectly that they would splinter into dust at the
touch of a needle; I have observed the gradual
and entire cessation of every function; I have
taken care that neither moss nor dirt nor moisture
remained. In this state I have kept them for
STUDIES IN ANIMAL LIFE.
113
variable and indefinite periods; and have found
that in almost every instance, the moistening of
the tissues was attended by a renewal of the action
of the heart and branchiæ-in short, a renewal of
life. I believe the same result is attainable, with
ordinary care, by any experimentalist, who may
doubt its authenticity."
If my correspondent will take the trouble of con-
sulting M. Broca's Report, he will see in detail
what M. Broca summarily declares, namely, that
all the physiologists who have written for or
against the resuscitation of animals have, in spite
of their differences, admitted with one accord, as an
incontestable axiom of biology, "that complete de-
siccation is the certain index of complete death."
And this unanimity only gives a deeper interest
to the question under discussion. Because if
absolute desiccation is death, the sole difficulty
remains in determining whether it is possible for
an animal so desiccated to become once more
permeated with water, and thus actually revive-
regain its lost life?
8
114
STUDIES IN ANIMAL LIFE.
CHAPTER IV.
An extinct animal recognized by its tooth: how came this to be
possible?-The task of classification-Artificial and natural
methods-Linnæus, and his baptism of the animal kingdom:
his scheme of classification-What is there underlying all
true classification ?—The chief groups-What is a species ?—
Re-statement of the question respecting the fixity or variability
of species-The two hypotheses-Illustration drawn from the
Romance languages-Caution to disputants.
I was one day talking with Professor Owen in the
Hunterian Museum, when a gentleman approached
with a request to be informed respecting the nature
of a curious fossil, which had been dug up by one
of his workmen. As he drew the fossil from
a small bag and was about to hand it for examina-
tion, Owen quietly remarked :-"That is the third
molar of the under-jaw of an extinct species of
rhinoceros." The astonishment of the gentleman
at this precise and confident description of the
fossil, before even it had quitted his hands, was
doubtless very great. I know that mine was;
STUDIES IN ANIMAL LIFE.
115
until the reflection occurred that if some one, little
acquainted with editions, had drawn a volume from
his pocket, declaring he had found it in an old
chest, any bibliophile would have been able to say
at a glance: "That is an Elzevir; " or, "That is
one of the Tauchnitz classics, stereotyped at
Leipzig." Owen is as familiar with the aspect
of the teeth of animals, living and extinct, as a
student is with the aspect of editions. Yet before
that knowledge could have been acquired, before
he could say thus confidently that the tooth
belonged to an extinct species of rhinoceros, the
united labours of thousands of diligent inquirers
must have been directed to the classification of
animals. How could he know that the rhinoceros
was of that particular species rather than another?
and what is meant by species? To trace the
history of this confidence would be to tell the long
story of zoological investigation: a story too long
for narration here, though we may pause awhile to
consider its difficulties.
To make a classified catalogue of the books in
the British Museum would be a gigantic task; but
8-2
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STUDIES IN ANIMAL LIFE.
imagine what that task would be if all the title-
pages and other external indications were de-
stroyed! The first attempts would necessarily be ·
of a rough approximative kind, merely endeavouring
to make a sort of provisional order amid the chaos,
after which succeeding labours might introduce
better and better arrangements. The books might
first be grouped according to size; but having
got them together, it would soon be discovered
that size was no indication of their contents:
quarto poems and duodecimo histories, octavo
grammars and folio dictionaries, would imme-
diately give warning that some other arrangement
was needed. Nor would it be better to separate
the books according to the languages in which
they were written. The presence or absence of
"illustrations would furnish no better guide;
while the bindings would soon be found to follow
no rule. Indeed, one by one all the external
characters would prove unsatisfactory, and the
labourers would finally have to decide upon some
internal characters. Having read enough of each
book to ascertain whether it was poetry or prose :
""
STUDIES IN ANIMAL LIFE.
117
and if poetry, whether dramatic, epic, lyric, or
satiric; and if prose, whether history, philosophy,
theology, philology, science, fiction, or essay: a
rough classification could be made; but even then
there would be many difficulties: such as where
to place a work on the philosophy of history-or
the history of science,—or theology under the
guise of science-or essays on very different
subjects; while some works would defy classifi-
cation.
Gigantic as this labour would be, it would be
trifling compared with the labour of classifying
all the animals now living (not to mention extinct
species), so that the place of any one might be
securely and rapidly determined; yet the persis-
tent zeal and sagacity of zoologists have done for
the animal kingdom what has not yet been done
for the library of the Museum, although the titles
of the books are not absent. It has been done
by patient reading of the contents-by anatomical
investigation of the internal structure of animals.
Except on a basis of comparative anatomy, there
could have been no better classification of animals
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than a classification of books according to size,
language, binding, &c.
An unscientific Pliny could group animals
according to their habitat; but when it was known
that whales, though living in the water and
swimming like fish, were in reality constructed
like air-breathing quadrupeds-when it was known
that animals differing so widely as bees, birds,
bats, and flying squirrels, or as otters, scals, and
cuttle-fish, lived together in the same element, it
became obvious that such a principle of arrange-
ment could lead to no practical result.
Nor would it suffice to class animals according
to their modes of feeding; since in all classes
there are samples of each mode. Equally unsatis-
factory would be external form-the seal and the
whale resembling fishes, the worm resembling the
eel, and the eel the serpent.
Two things were necessary: first, that the
structure of various animals should be minutely
studied and described which is equivalent to
reading the books to be classified;-and secondly,
that some artificial method should be devised of
STUDIES IN ANIMAL LIFE.
119
so arranging the immense mass of details as to
enable them to be remembered, and also to enable
fresh discoveries readily to find a place in the
system. We may be perfectly familiar with the
contents of a book, yet wholly at a loss where to
place it. If we have to catalogue Hegel's Philo-
sophy of History, for example, it becomes a diffi-
cult question whether to place it under the rubric
of philosophy, or under that of history. To
decide this point, we must have some system of
classification.
In the attempts to construct a system, naturalists
are commonly said to have followed two methods:
the artificial and the natural. The artificial
method seizes some one prominent characteristic,
and groups all the individuals together which
agree in this one respect. In Botany the artifi-
cial method classes plants according to the organs
of reproduction; but this has been found so very
imperfect that it has been abandoned, and the
natural method has been substituted, according to
which the whole structure of the plant determines
its place. If flying were taken as the artificial
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STUDIES IN ANIMAL LIFE.
basis for the grouping of some animals, we should
find insects and birds, bats and flying squirrels,
grouped together; but the natural method, taking
into consideration not one character, but all essen-
tial characters, finds that insects, birds, and bats
differ profoundly in their organization: the insect
has wings, but its wings are not formed like those
of the bird, nor are those of the bird formed like
those of the bat. The insect does not breathe
by lungs, like the bird and the bat: it has no
internal skeleton, like the bird and the bat; and
the bird, although it has many points in common
with the bat, does not, like it, suckle its young;
and thus we may run over the characters of each
organism, and find that the three animals belong
to widely different groups.
It is to Linnæus that we are indebted for the
most ingenious and comprehensive of the many
schemes invented for the cataloguing of animal
forms; and modern attempts at classification are
only improvements on the plan he laid down.
First we may notice his admirable invention of
the double names. It had been the custom to
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121
""
designate plants and animals according to some
name common to a large group, to which was
added a description more or less characteristic.
An idea may be formed of the necessity of a
reform, by conceiving what a laborious and up-
certain process it would be if our friends spoke
to us of having seen a dog in the garden, and
on our asking what kind of dog, instead of their
saying "a terrier, a bull-terrier, or a skye-terrier,'
they were to attempt a description of the dog.
Something of this kind was the labour of under-
standing the nature of an animal from the vague
description of it given by naturalists. Linnæus
rebaptized the whole animal kingdom upon one
intelligible principle. He continued to employ the
name common to each group, such as that of Felis
for the cats, which became the generic name; and
in lieu of the description which was given of
each different kind, to indicate that it was a lion,
a tiger, a leopard, or a domestic cat, he affixed
a specific name: thus the animal bearing the
description of a lion became Felis leo; the tiger,
Felis tigris; the leopard, Felis leopardus; and
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STUDIES IN ANIMAL LIFE.
our domestic friend, Felis catus. These double.
names, as Vogt remarks, are like the Christian-
and sur-names by which we distinguish the various
members of one family; and instead of speaking
of Tomkinson with the flabby face, and Tomkinson
with the square forehead, we simply say John
and William Tomkinson.
Linnæus did more than this. He not only
fixed definite conceptions of Species and Genera,
but introduced those of Orders and Classes. Cuvier
added Families to Genera, and Sub-kingdoms
(embranchements) to Classes. Thus a scheme
was elaborated by which the whole animal king-
dom was arranged in subordinate groups: the
sub-kingdoms were divided into classes, the classes
into orders, the orders into families, the families
into genera, the genera into species, and the
species into varieties.
The guiding principle of anatomical resemblance
determined each of these divisions. Those largest
groups, which resemble each other only in having
what is called the typical character in common,
are brought together under the first head. Thus
STUDIES IN ANIMAL LIFE.
123
1
all the groups which agree in possessing a back-
bone and internal skeleton, although they differ
widely in form, structure, and habitat, do neverthe-
less resemble each other more than they resemble
the groups which have no backbone.
This great division having been formed, it is seen
to arrange itself in very obvious minor divisions,
or Classes the mammalia, birds, reptiles, and
fishes. All mammals resemble each other more
than they resemble birds; all reptiles resemble
each other more than they resemble fishes (in spite
of the superficial resemblance between serpents
and eels or lampreys).
Each Class again falls into the minor groups of
Orders; and on the same principles: the monkeys
being obviously distinguished from rodents, and
the carnivora from the ruminating animals; and
so of the rest.
In each Order there are generally Families, and
the Families fall into Genera, which differ from
each other only in fewer and less important
characters.
The Genera include groups which have still
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STUDIES IN ANIMAL LIFE.
fewer differences, and are called Species; and
these again include groups which have only minute
and unimportant differences of colour, size, and
the like, and are called Sub-species, or Varieties.
Whoever looks at the immensity of the animal
kingdom, and observes how intelligibly and syste-
matically it is arranged in these various divisions,
will admit that, however imperfect, the scheme is
a magnificent product of human ingenuity and
labour. It is not an arbitrary arrangement, like
the grouping of the stars in constellations; it
expresses, though obscurely, the real order of
Nature. All true Classifications should be to
forms what laws are to phenomena: the one
reducing varieties to systematic order, as the
other reduces phenomena to their relation of
sequence.
Now if it be true that the classification expresses
the real order of nature, and not simply the order
which we may find convenient, there will be
something more than mere resemblance indicated
in the various groups; or, rather, let me say,
this resemblance itself is the consequence of some
STUDIES IN ANIMAL LIFE.
125
community in the things compared, and will there-
fore be the mark of some deeper cause. What
is this cause? Mr. Darwin holds that "pro-
pinquity of descent-the only known cause of the
similarity of organic beings-is the bond, hidden
as it is by various degrees of modification, which
is partially revealed to us by our classifications"*
-"that the characters which naturalists consider
as showing true affinity between any two or more
species are those which have been inherited from
a common parent, and in so far all true classifica-
tion is genealogical; that community of descent
is the hidden bond which naturalists have been
unconsciously seeking, and not some unknown
plan of creation, or the enunciation of general
propositions, and the mere putting together and
separating objects more or less alike."†
Before proceeding to open the philosophical
discussion which inevitably rises on the mention
of Mr. Darwin's book, I will here set down the
chief groups, according to Cuvier's classification,
for the benefit of the tyro in natural history, who
* DARWIN: Origin of Species, p. 414. † Ibid. p. 420.
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STUDIES IN ANIMAL LIFE.
will easily remember them, and will find the
knowledge constantly invoked.
There are four Sub-kingdoms, or Branches :-
1. Vertebrata.
Radiata.
2. Mollusca. 3. Articulata. 4.
The VERTEBRATA consist of four classes:-
Mammalia, Birds, Reptiles, and Fishes.
The MOLLUSCA consist of six classes :-Cepha-
lopoda (cuttlefish), Pteropoda, Gasteropoda (snails,
&c.), Acephala (oysters, &c.), Brachiopoda, and
Cirrhopoda (barnacles).-N.B. This last class of
barnacles is now removed from the Molluscs and
placed among the Crustaceans.
The ARTICULATA are composed of four classes:
Annelids (worms), Crustacea (lobsters, crabs, &c.),
Arachnida (spiders), and Insecta.
The RADIATA embrace all the remaining forms;
but this group has been so altered since Cuvier's
time, that I will not burden your memory just
now with an enumeration of the details.
The reader is now in a condition to appreciate
the general line of argument adopted in the dis-
cussion of Mr. Darwin's book, which is at present
STUDIES IN ANIMAL LIFE.
127
exciting very great attention, and which will, at
any rate, aid in general culture by opening to
many minds new tracts of thought. The benefit
in this direction is, however, considerably lessened
by the extreme vagueness which is commonly
attached to the word "species," as well as by the
great want of philosophic culture which im-
poverishes the majority of our naturalists. I have
heard, or read, few arguments on this subject
which have not impressed me with the sense that
the disputants really attached no distinct ideas to
many of the phrases they were uttering. Yet it
is obvious that we must first settle what are the
facts grouped together and indicated by the word
"species," before we can carry on any discussion
as to the origin of species. To be battling about
the fixity or variability of species, without having
rigorously settled what species is, can lead to no
edifying result.
It is notorious that if you ask even a zoologist,
What is a species? you will almost always find
that he has only a very vague answer to give ;
and if his answer be precise, it will be the pre-
128
STUDIES IN ANIMAL LIFE.
cision of error, and will vanish into contradictions
directly it is examined. The consequence of this
is, that even the ablest zoologists are constantly
at variance as to specific characters, and often
cannot agree whether an animal shall be con-
sidered of a new species, or only a variety.
There could be no such disagreements if specific
characters were definite: if we knew what species
meant, once and for all. Ask a chemist, What
is a salt? What an acid? and his reply will be
definite, and uniformly the same: what he says,
all chemists will repeat. Not so the zoologist.
Sometimes he will class two animals as of
different species, when they only differ in colour,
in size, or in the numbers of tentacles, &c.; at
other times he will class animals as belonging
to the same species, although they differ in size,
colour, shape, instincts, habits, &c.
The dog,
for example, is said to be one species with many
varieties, or races. But contrast the pug-dog with
the greyhound, the spaniel with the mastiff, the
bulldog with the Newfoundland, the setter with
the terrier, the sheepdog with the pointer: note
STUDIES IN ANIMAL LIFE.
129
the striking differences in their structure and
their instincts and you will find that they
differ as widely as some genera, and as most
species. If these varieties inhabited different
countries—if the pug were peculiar to Australia,
and the mastiff to Spain-there is not a naturalist
but would class them as of different species. The
same remark applies to pigeons and ducks, oxen
and sheep.
The reason of this uncertainty is that the thing
Species does not exist: the term expresses an
abstraction, like Virtue, or Whiteness; not a
definite concrete reality, which can be separated
from other things, and always be found the same.
Nature produces individuals; these individuals
resemble each other in varying degrees; according
to their resemblances we group them together as
classes, orders, genera, and species; but these
terms only express the relations of resemblance,
they do not indicate the existence of such things
as classes, orders, genera, or species.
*
* CUVIER says, in so many words, that classes, orders, and
genera, are abstractions, et rien de pareil n'existe dans la nature ;
but that species is not an abstraction!-See Lettres à Pfaff, p. 179.
9
130
STUDIES IN ANIMAL LIFE.
There is a reality indicated by each term-that is
to say, a real relation; but there is no objective
existence of which we could say, This is variable,
This is immutable. Pecisely as there is a real
relation indicated by the term Goodness, but there
is no Goodness apart from the virtuous actions
and feelings which we group together under this
term. It is true that metaphysicians in past
ages angrily debated respecting the Immutability
of Virtue, and had no more suspicion of their
absurdity, than moderns have who debate respect-
ing the Fixity of Species. Yet no sooner do we
understand that Species means a relation of
resemblance between animals, than the question of
the Fixity, or Variability, of Species resolves
itself into this: Can there be any variation in
the resemblances of closely allied animals? A
question which would never be asked.
No one has thought of raising the question of
the fixity of varieties, yet it is as legitimate as that
of the fixity of species; and we might also argue
for the fixity of genera, orders, classes; the fixity
of all these being implied in the very terms; since.
STUDIES IN ANIMAL LIFE.
131
no sooner does any departure from the type
present itself, than by that it is excluded from
the category; no sooner does a white object
become gray, or yellow, than it is excluded from
the class of white objects. Here, therefore, is a
sense in which the phrase "fixity of species is
indisputable; but in this sense the phrase has
never been disputed. When zoologists have
maintained that species are variable, they have
meant that animal forms are variable; and these
variations, gradually accumulating, result at last
in such differences as are called specific. Although
some zoologists, and speculators who were not
zoologists, have believed that the possibility of
variation is so great that one species may actually
be transmuted into another, i.e., that an ass may
be developed into a horse,-yet most thinkers
are now agreed that such violent changes are
impossible; and that every new form becomes
established only through the long and gradual
accumulation of minute differences in divergent
directions.
+
It is clear, from what has just been said, that
9—2
132
STUDIES IN ANIMAL LIFE.
the many angry discussions respecting the fixity
of species, which, since the days of Lamarck, have
disturbed the amity of zoologists and speculative
philosophers, would have been considerably ab-
breviated, had men distinctly appreciated the
equivoque which rendered their arguments hazy.
I am far from implying that the battle was purely
a verbal one. I believe there was a real and
important distinction in the doctrines of the two
camps; but it seems to me that had a clear
understanding of the fact that Species was an
abstract term, been uniformly present to their
minds, they would have sooner come to an agree-
ment. Instead of the confusing disputes as to
whether one Species could ever become another
Species, the question would have been, Are animal
forms changeable? Can the descendants of animals.
become so unlike their ancestors, in certain pecu-
liarities of structure or instinct, as to be classed by
naturalists as a different species ?
No sooner is the question thus disengaged from
equivoque, than its discussion becomes narrowed
within well-marked limits. That animal forms
STUDIES IN ANIMAL LIFE.
133
are variable, is disputed by no zoologist. The
only question which remains is this: To what
extent are animal forms variable? The answers
given have been two: one school declaring that
the extent of variability is limited to those trifling
characteristics which mark the different varieties
of each species; the other school declaring that
the variability is indefinite, and that all animal
forms may have arisen from successive modifi-
cations of a very few types, or even of one type.
Now, I would call your attention to one point
in this discussion, which ought to be remembered
when antagonists are growing angry and bitter
over the subject: it is, that both these opinions
are necessarily hypothetical-there can be nothing
like positive proof adduced on either side. The
utmost that either hypothesis can claim is, that it
is more consistent with general analogies, and
better serves to bring our knowledge of various
points into harmony. Neither of them can claim
to be a truth which warrants dogmatic decision.
Of these two hypotheses, the first has the
weight and majority of authoritative adherents.
134
STUDIES IN ANIMAL LIFE.
It declares that all the different kinds of Cats, for
example, were distinct and independent creations,
each species being originally what we see it to be
now, and what it will continue to be as long as it
exists lions, panthers, pumas, leopards, tigers,
jaguars, ocelots, and domestic cats, being so many
original stocks, and not so many divergent forms of
one original stock. The second hypothesis declares
that all these kinds of cats represent divergencies
of the original stock, precisely as the Varieties of
each kind represent the divergencies of each Species.
It is true that each species, when once formed,
only admits of limited variations; any cause
which should push the variation beyond certain
limits would destroy the species, because by
species is meant the group of animals contained
within those limits. Let us suppose the original
stock from which all these kinds of cats have
sprung, to have become modified into lions,
leopards, and tigers-in other words, that the
gradual accumulation of divergencies has resulted
in the whole family of cats existing under these
three forms. The lions will form a distinct
STUDIES IN ANIMAL LIFE.
135
species; this species varies, and in the course
of long variation a new species, the puma, rises
by the side of it. The leopards also vary, and
let us suppose their variation at length assumes
so marked a form,-in the ocelot,-that we class
it as a new species. There is nothing in this
hypothesis but what is strictly consonant with
analogies; it is only extending to Species what
we know to be the fact with respect to Varieties;
and these Varieties which we know to have been
produced from one and the same Species are often
more widely separated from each other than the
lion is from the puma, or the leopard from the
ocelot. Mr. Darwin remarks that "at least a
score of pigeons might be chosen, which, if shown
to an ornithologist, and he were told that they
were wild birds, would certainly, I think, be
ranked by him as well-defined species. Moreover,
I do not believe that any ornithologist would
place the English carrier, the short-faced tumbler,
the runt, the barb, the pouter and fantail in the
same genus! more especially as in each of these
breeds several truly-inherited sub-breeds or species,
136
STUDIES IN ANIMAL LIFE.
as he might have called them, could be shown
him."
The development of numerous specific forms,
widely distinguished from each other, out of one
common stock, is not a whit more improbable
than the development of numerous distinct lan-
guages out of a common parent language, which
modern philologists have proved to be indubitably
the case. Indeed, there is a very remarkable
analogy between philology and zoology in this
respect just as the comparative anatomist traces
the existence of similar organs, and similar
connections of these organs, throughout the
various animals classed under one type, so does
the comparative philologist detect the family
likeness in the various languages scattered from
China to the Basque provinces, and from Cape
Comorin across the Caucasus to Lapland—a like-
ness which assures him that the Teutonic, Celtic,
Windic, Italic, Hellenic, Iranic, and Indic lan-
guages are of common origin, and separated from
the Arabian, Aramean, and Hebrew languages,
which have another origin. Let us bring together
STUDIES IN ANIMAL LIFE.
137
a Frenchman, a Spaniard, an Italian, a Portu-
guese, a Wallachian, and a Rhætian, and we shall
hear six very different languages spoken, the
speakers severally unintelligible to each other,
their languages differing so widely that one cannot
be regarded as the modification of the other; yet
we know most positively that all these languages
are offshoots from the Latin, which was once a
living language, but which is now, so to speak, a
fossil. The various species of cats do not differ
more than these six languages differ: and yet the
resemblances point in each case to a common
origin. Max Müller, in his brilliant essay on
Comparative Mythology,* has said :-
"If we knew nothing of the existence of Latin
-if all historical documents previous to the
fifteenth century had been lost-if tradition, even,
was silent as to the former existence of a Roman
empire, a mere comparison of the six Roman
dialects would enable us to say, that at some time
there must have been a language from which all
these modern dialects derived their origin in
* See Oxford Essays, 1856.
138
STUDIES IN ANIMAL LIFE.
common; for without this supposition it would be
impossible to account for the facts exhibited by
these dialects. Let us look at the auxiliary verb.
We find :-
Italian.
Wallachian.
Rhatian.
I am
sono
sum sunt
sunt
Thou art.
sci
es
eis
He is
We are
e
•
é (este)
ei
siamo
suntemu
essen
You are
They are
siete
sunteti
esses
sono
sunt
cân (sun)
Spanish.
Portuguese.
French.
I am
soy
Sou
Thou art
eres
es
He is
es
he
We are
somos
somos
You are
sois
sois
They are
son
são
sont
suis
es
est
sommes
êtes (estes)
It is clear, even from a short consideration of
these forms, first, that all are but varieties of one
common type; secondly, that it is impossible to
consider any one of these six paradigms as the
original from which the others had been borrowed.
To this we may add, thirdly, that in none of the
languages to which these verbal forms belong, do
we find the elements of which they could have
been composed. If we find such forms as j'ai
aimé, we can explain them by a mere reference
STUDIES IN ANIMAL LIFE.
139
to the radical means which French has still at its
command, and the same may be said even of
compounds like j'aimerai, i.e. je-aimer-ai, I have
to love, I shall love. But a change from je suis
to tu es is inexplicable by the light of French
These forms could not have grown,
grammar.
so to speak, on French soil, but must have been
handed down as relics from a former period-must
have existed in some language antecedent to any
of the Roman dialects. Now, fortunately, in this
case, we are not left to a mere inference, but as we
possess the Latin verb, we can prove how, by
phonetic corruption, and by mistaken analogies,
every one of the six paradigms is but a national
metamorphosis of the Latin original.
"Let us now look at another set of paradigms:-
Sanskrit. Lithuanian. Zend.
Doric.
I am
ásmi
esmi
ahmi
έμμι
Thou art
ási
essi
ahi
ἐσσὶ
He is
ásti
esti
Basti
ἐστί
We (two) are
'svás
esva
You (two) are
'sthás
esta
stho?
ἕστόν
They (two) are.
'stás
(esti)
sto?
ἐστόν
We are
'smás
esmi
hmahi
ἐσμές
You are
stha
este
stha
ἐστέ
They are.
sánti
(esti)
hĕnti
ἐντί
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STUDIES IN ANIMAL LIFE.
Old Slavonic.
Latin.
Gothic.
Armen.
I am.
yesmě
sum
im
em
Thou art
yesi
es
is
es
He is
yestŏ
est
ist
ê
We (two) are
yesva
siju
You (two) are
·
yesta
sijuts
They (two) are.
yesta
We are
yesmo
sumus
sijum
emq
You are
yeste
estis
sijup
êq
They are
somtě
sunt
sind
en
"From a careful consideration of these forms,
we ought to draw exactly the same conclusion;
firstly, that all are but varieties of one common
type; secondly, that it is impossible to consider
any of them as the original from which the others
have been borrowed; and thirdly, that here again,
none of the languages in which these verbal forms
occur possess the elements of which they are
composed."
All these languages resemble each other so
closely that they point to some more ancient
language which was to them what Latin was to
the six Romance languages; and in the same
way we are justified in supposing that all the
classes of the vertebrate animals point to the
existence of some elder type, now extinct, from
which they were all developed.
STUDIES IN ANIMAL LIFE.
141
I have thus stated what are the two hypotheses
on this question. There is only one more pre-
liminary which it is needful to notice here, and
that is, to caution the reader against the tendency,
unhappily too common, of supposing that an
adversary holds opinions which are transparently
absurd. When we hear an hypothesis which is
either novel, or unacceptable to us, we are apt to
draw some very ridiculous conclusion from it, and
to assume that this conclusion is seriously held by
its upholders. Thus the zoologists who maintain
the variability of species, are sometimes asked if
they believe a goose was developed out of an
oyster, or a rhinoceros from a mouse? the ques-
tioner apparently having no misgiving as to the
candour of his ridicule.
There are three modes of combating a doctrine.
The first is to point out its strongest positions,
and then show them to be erroneous or incom-
plete; but this plan is generally difficult, and
sometimes impossible; it is not, therefore, much
in vogue. The second is to render the doctrine
ridiculous, by pretending that it includes certain
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STUDIES IN ANIMAL LIFE.
extravagant propositions, of which it is entirely
innocent. The third is to render the doctrine
odious, by forcing on it certain conclusions, which
it would repudiate, but which are declared to be
"the inevitable consequences" of such a doctrine.
Now it is undoubtedly true that men frequently
maintain very absurd opinions; but it is neither
candid, nor wise, to assume that men who other-
wise are certainly not fools, hold opinions the
absurdity of which is transparent.
Let us not, therefore, tax the followers of
Lamarck, Geoffroy St. Hilaire, or Mr. Darwin
with absurdities they have not advocated; but
rather endeavour to see what solid argument they
have for the basis of their hypothesis.
STUDIES IN ANIMAL LIFE,
143
CHAPTER V.
Talking in beetles-Identity of Egyptian animals with those now
existing: does this prove fixity of species ?-Examination of
the celebrated argument of species not having altered in four
thousand years-Impossibility of distinguishing species from
varieties-The affinities of animals-New facts proving the
fertility of Hybrids-The hare and the rabbit contrasted-
Doubts respecting the development hypothesis-On hypothesis
in Natural History-Pliny, and his notion on the formation of
pearls-Are pearls owing to a disease of the oyster ?-Forma-
tion of the shell; origin of pearls-How the Chinese manu-
facture pearls.
A WITTY friend of mine expressed her sense of
the remoteness of the ancient Egyptians, and her
difficulty in sympathizing with them, by declaring
that "they talked in beetles, you know." She
referred, of course, to the hieroglyphics in which
that curious people now speak to us from ancient
tombs.
Whether in
Whether in their beetle-speech those
swarthy sages were eloquent and wise, or obscure
and otherwise, it is certain that entomologists of
our day recognize their beetles as belonging to
the same species that are now gathered into
144
STUDIES IN ANIMAL LIFE.
collections.
our
Such as the Egyptians knew them,
such we know them now. Nay, the sacred cats
found in those ancient tombs, are cats of the
same kind as our own familiar mousers they
purred before Pharaoh as they purr on
hearthrugs; and the descendants of the very
dogs which irreligiously worried those cats, are
to this day worrying the descendants of those
sacred cats. The grains of wheat, which the
savans found in the Egyptian tombs, were planted
in the soil of France, and grew into waving corn,
in no respect distinguishable from the corn grown
from the grain of the previous year.
Have these familiar facts any important signi-
ficance? Are we entitled to draw any conclusion
from the testimony of paintings and sculptures,
at least four thousand years old, which show that
several of our well-known Species of animals,
and several of the well-marked Races of men,
existed then, and have not changed since then?
Nimrod hunted with dogs and horses, which
would be claimed as ancestors by the dogs and
horses at Melton Mowbray. The Negroes who
STUDIES IN ANIMAL LIFE.
145
attended Semiramis and Rhamses are in every
respect similar to the Negroes now toiling amid
the sugar-canes of Alabama. If, during four
thousand years Species and Races have not
changed, why should we suppose that they ever
will change? Why should we not take our stand
on that testimony, and assert that Species are
unchangeable.
Such has been the argument of Cuvier and
his followers; an argument on which they have
laid great stress, and which they have further
strengthened by a challenge to adversaries to
produce one single case where a transmutation
of species has taken place :-"Here we show
you evidence that Species have persisted un-
altered during four thousand years, and you
cannot show us a single case of Species having
changed-you cannot show us one case of a
wolf becoming a dog, an ass becoming a horse,
a hare becoming a rabbit. Yet you must admit
that if there were any inherent tendency to
change, four thousand years is a long enough
period for that tendency to display itself in; and
10
146
STUDIES IN ANIMAL LIFE.
we ought to see a very marked difference between
the Species which lived under Semiramis, and
those which are living under Victoria. Instead
of this, we see that there has been no change:
the dog has remained a dog, the horse has re-
mained a horse; every Species retains its well-
marked characters.'
No one will say that I have not done justice
to this argument. I have stated it as clearly
and forcibly as possible, not with any design to
captivate your assent, but to make the answer
complete. This argument is the cheval de bataille
of the Cuvier school; but like many other argu-
mentative war-horses, it proves, on close inspection,
to be spavined and brokenwinded.
The first criticism we must pass on it is, that
it implies the existence of Species as a thing,
which can be spoken of as fixed or variable;
whereas, as we saw in the last chapter, Species
is an abstraction, like Whiteness or Strength.
No one supposes that there exists any whiteness
apart from white things, or strength apart from
strong things; yet the naturalists who maintain
STUDIES IN ANIMAL LIFE.
147
the fixity of Species, constantly talk as if Species
existed independently of the individual animals.
Instead of saying that by the word Species is
indicated a certain group of characters, and that
whenever we meet with this group we say, here
is an animal of the same Species; they explicitly
declare, or tacitly imply, that although an indi-
vidual dog may vary, there is something above
all individuals-the Species-and that cannot
vary.
As it is possible some. readers may protest
that no respectable authority in modern times.
ever held the opinion here imputed to a school,
I will quote the very explicit language of one of
Cuvier's disciples-the last editor of Buffon—
who, no later than 1856, could declare that
"Species are the primitive forms of Nature.
Individuals are nothing but the representatives—
the copies of these forms: Les espèces sont les
formes primitives de la Nature. Les individus
n'en sont que des représentations, des copies."
According to this very explicit, but very extra-
* FLOURENS: Cours de Physiologie Comparée, 1856, p. 9.
-
10-2
148
STUDIES IN ANIMAL LIFE.
vagant statement, an individual dog is nothing
but a copy of the primitive form-the typical
dog-the idea of a dog, as Plato would say;
and of course, if this be true, it matters little
how widely individual dogs may vary, the type,
or species, of which it is the representative,
remains unaltered.
Indeed it is on this ground that many physio-
logists explain the fact of hereditary transmission:
the individual may vary, it is said, but the species
is preserved; and if a dog, without its fore paws,
has offspring, every one of which possesses the
fore paws, the reason is, that l'idée de l'espèce
se reproduit dans le fruit, et lui donne des
organes qui manquaient au père ou à la mère.*
It is not easy to understand how the idea of
species can reproduce itself, and give the off-
spring of a dog the organs which were wanting
in the parents; but to those who believe that
Species exist independently of individuals, and
* BURDACH: Physiologie, ii. 245.-"The idea of the species
is reproduced in the offspring, and bestows the organs which
the parent had lost."
STUDIES IN ANIMAL LIFE.
149
form the only real existences, the conception may
be easier.
I have too much respect for the reader to drag
him through a refutation of such philosophy as
this; the statement of the opinion is enough.
And yet, unless some such opinion be main-
tained, the doctrine of Fixity of Species is
without a basis; for if it be said that the group
of characters which constitute the dog are incap-
able of change, and in this sense Species are
fixed, we have to ask what evidence there can
be for such an assertion ? since it is notorious
that individual dogs do show a change in some
of the characters of the group. We shall be
referred to the Egyptian tombs for evidence.
M. Flourens assures us that not only are these
tombs evidence that Species have not changed
in four thousand years, but that no species has
changed―aucune espèce n'a changé—which is
surely stepping a long way beyond the precincts
of the tombs ?
It may be paradoxical, but it is strictly true,
that the fact of particular species having remained
150
STUDIES IN ANIMAL LIFE.
CC
unaltered during four thousand years, does not
add the slightest weight to the evidence in favour
of the fixity of Species. "What!" some may
exclaim, do you pretend that four thousand
years is not a period long enough to prove the
fixity of animal forms?" Yes; I affirm that
four thousand, or forty thousand, prove no more
than four. You would not suppose that I had
strengthened my case if, instead of contenting
myself with stating reasons once, I repeated these
same reasons during forty successive pages; you
would remind me that this iteration was not
cumulation, and that no force was given to my
fortieth assertion which the first wanted. Why,
then, do you ask me to accept the repetition of
the same fact four thousand times over, as an
increase of evidence? It is a familiar fact that
like produces like, that dogs resemble dogs, and
do not resemble buffaloes; this fact is, of course,
deepened in our conviction by the unvarying
evidence we see around us, and is guaranteed
by the philosophical axiom that like causes pro-
duce like effects; but when once such a con-
STUDIES IN ANIMAL LIFE.
151
ception is formed, it can gain no fresh strength
from any particular instance. If we believe that
crows are black, we do not hold that belief
more firmly when we are shown that crows were
black four thousand years ago. In like manner,
if it is an admitted fact that individuals always
reproduce individuals closely resembling them-
selves, it is not a whit more surprising that the
dogs of Victoria should resemble the dogs of
Semiramis, than that they should resemble their
parents: the chain of four thousand years is
made up of many links, each link being a
repetition of the other. So long as a singlë
pair of dogs, resembling each other, unite, sọ
long will there be specimens of that species ;
simply because the children inherit the charac-
teristics of the parents. So long as Negroes
marry with Negroes, and Jews with Jews, so
long must there be a perpetuation of the Negro
and Jewish types; but the tenth generation adds
nothing to the evidence of the first, nor the ten-
thousandth to the tenth.
I believe that this fallacy, which destroys the
152
STUDIES IN ANIMAL LIFE.
whole value of the Cuvierian argument, has not
before been pointed out; and even now, you may,
perhaps, ask if the fixity of Species is not proved
by the fact that like produces like? Not so. Nay
it is only by the aid of such a fact in organic nature
that we can imagine new species to have arisen :
in other words, those who believe in the variability
of Species, and the introduction of new forms by
means of modification from the old, always invoke
the law of hereditary transmission as the means
of establishing accidental variations.
Thus, let us suppose the Egyptian king to have
had one hundred dogs, all of them staghounds, and
no other form of dog to have existed at that time
in that country; the dog species would be repre-
sented by the staghound. These staghounds would
transmit to their offspring all their specific charac-
ters. But, as every one knows, however much dogs
may resemble each other, they always present
individual differences in size, colour, strength,
intelligence, &c. Now, if any one of these dif-
ferences should happen to become marked, and to
increase by the intermarriage of two dogs similarly
STUDIES IN ANIMAL LIFE.
153
distinguished by the marked peculiarity, this pecu-
liarity would in time become established by
hereditary transmission, and would form the start-
ing-point of a new race of dogs-say the greyhound
-unless it were obliterated by intermarriage with
dogs of the old type. In the former case, we
should have two races of dogs among the descend-
ants of those figured on the Egyptian tombs; but
as one of these races would still preserve the
original staghound type, Cuvier would refer to it
as a proof that species had not varied. We, on
the other hand, should point to the greyhound
as proof that animal forms are variable, and that
a new form had arisen from modification of the
old.
An objection will at once be raised to this illus-
tration, to the effect that all zoologists admit the
possibility of new Varieties, or Races, being
formed; but they deny that new Species can be
formed. It is here that the equivoque of the
word Species prevents a clear understanding of
each other's argument. Whiteness may justly be
said to be unalterable; but white things may vary
154
STUDIES IN ANIMAL LIFE.
-they may become gray, or yellow. In like
manner Species must be invariable, because Species
is a word indicating a particular group of characters;
but animals may vary in these characters; they
may present some of the characters less, or more,
developed; and they may even want some of them.
Now as there is no absolute standard of what
constitutes Species, what Sub-species, and what
Varieties, it becomes impossible to say whether any
individual variation in an animal form shall consti-
tute a new Variety, or a new Species. With regard
to dogs the differences between the various races
are so numerous, and so marked, as would suffice
to constitute species and even genera, in other
groups of animals.
We must reliquish the idea of proving anything
by the paintings and sculptures of the ancients.
When we find an Egyptian plough closely re-
sembling the plough still in use in some places, we
may identify it as of the same "Species" as our
own; but this does not disprove the fact that
steam-ploughs, and ploughs of various construction,
have been since invented, all of them being modi-
STUDIES IN ANIMAL LIFE.
155
fications of the original type. Formerly, and for
many years, the stage-coach was our approved
mode of conveyance and it is still kept up in
some districts; nevertheless, modifications of coach-
road into tramroad, and tramroad into railroad,
have gradually resulted in a mode of conveyance
utterly unlike the stage-coach. It is the same with
animals. Let us never forget that Species have no
existence. Only individuals exist, and these all
vary more or less from each other. When the
variations are slight, they have no name; when
they are more marked, and are transmitted from
one generation to another, they constitute particu-
lar Races, or Varieties; when the differences are
still more marked they constitute Sub-species; but,
as Mr. Darwin says, "Certainly no clear line of
demarcation has yet been drawn between Species
and Sub-species; that is, the forms which in the
opinion of some naturalists come very near to, but
do not quite arrive at the rank of Species; or again,
between Sub-species and well-marked Varieties, or
between lesser Varieties and individual differences.
These differences blend into each other in an
156
STUDIES IN ANIMAL LIFE.
insensible series; and a series impresses the mind
with the idea of an actual passage."
But the same process of divergence which esta-
blishes Varieties out of individual differences, and
Species out of Varieties, also serves to establish
Genera out of Species, Orders out of Genera, and
Classes out of Orders.
It is, doubtless, difficult to conceive by what
process of modification, two animals of distinct
Genera, say a dog and a cat, were produced from a
common stock; but organic analogies in abundance
render it easy of belief. If we knew as much of
zoology as we do of embryology, in respect of the
affinities of divergent forms, it would be far less
surprising that two different Genera should arise
from a common stock, than that all the various
parts of the skeleton should arise from a common
osseous element. We know that the jaws are
identical with arms and legs-both being divergent
modifications of a common osseous structure. We
know that the arm of a man is identical with the fin
of a whale, or the wing of a bird. The differences
here in form, size, and function are much greater
STUDIES IN ANIMAL LIFE.
157
than the differences which establish orders and
classes in the animal series.
Unless animal forms were modifications of some
common type, it would be difficult to explain their
remarkable affinities. As Mr. Darwin says, "It is
a truly wonderful fact-the wonder of which we are
apt to overlook from familiarity-that all animals
and all plants throughout all time and space should
be related to each other in group, subordinate to
group, in the manner which we everywhere behold,
namely, varieties of the same species most closely
related together, species of the same genus less
closely and unequally related together, forming
sections and sub-genera, species of distinct genera
much less closely related, and genera related in
different degrees, forming sub-families, families,
orders, sub-classes, and classes. The several sub-
ordinate groups in any class cannot be ranked in a
single file, but seem rather to be clustered round
points, and these round other points, and so on in
almost endless circles. On the view that each
species has been independently created, I can see
no explanation of this great fact in the classification
153
STUDIES IN ANIMAL LIFE.
of all organic beings; but to the best of my judg-
ment it is explained through inheritance, and the
complex action of natural selection, entailing ex-
tinction and divergence of character. The affinities
of all the beings of the same class have sometimes
been represented by a great tree. I believe this
simile largely speaks the truth. The green and
budding twigs may represent existing species; and
those produced during each former year may repre-
sent the long succession of extinct species. At
each period of growth all the growing twigs have
tried to branch out on all sides, and to overtop and
kill the surrounding twigs and branches, in the
same manner as species and groups of species have
tried to overmaster other species in the great
struggle for life. The limbs divided into great
branches, and these into lesser branches, were
themselves once, when the tree was small, budding
twigs; and this connection of the former and
present buds by ramifying branches, may well
represent the classification of all extinct and living
species in groups subordinate to groups. Of the
many twigs which flourished when the tree was a
STUDIES IN ANIMAL LIFE.
159
A
mere bush, only two or three, now grown into great
branches, yet survive and bear all the other
branches. So with the species which lived during
long-past geological periods, very few now have
living and modified descendants.
As buds
give rise by growth to fresh buds, and these, if
vigorous, branch out and overtop on all sides many
a feebler branch: so by generation, I believe, it has
been with the great Tree of Life, which fills with
its dead and broken branches the crust of the earth,
and covers the surface with its ever-branching and
beautiful ramifications."*
It will not be expected that in these brief and
desultory remarks I should touch on all, or nearly
all, the important points in the discussion re-
specting the Fixity of Species. Mr. Darwin's book
is in everybody's hands, and my object has been to
facilitate, if possible, the comprehension of his
book, and the adoption of a more philosophical
hypothesis, by pointing out the weakness of the
chief argument on the other side. There is one
more argument which may be noticed-the more
* DARWIN: Origin of Species, p. 128.
160
STUDIES IN ANIMAL LIFE.
so as it is constantly adduced with triumph by the
one school, and admitted as a difficulty by the
other. Its force is so great that it prevents many
from accepting the development hypothesis. It is
the argument founded on the alleged impossibility
of Hybrids continuing the race. More than two
or three generations of Hybrids, it is said, can
never be maintained; after that, the new form
perishes thus clearly showing how Nature repu-
diates such amalgamations, and keeps her species
jealously distinct and invariable. This argument
is held to be the touchstone of the doctrine of
species. I wish it were so; because, in that case,
the question would no longer be one of hypothesis,
since we have now the indubitable proof that some
Hybrids are fertile unto the thirteenth generation
and onwards.
A history of the various attempts which have
been made to prove and disprove the fertility of
Hybrids, would lead us beyond our limits; the
curious reader is referred to the works cited below.*
* ISIDORE GEOFFROY ST. HILAIRE: Hist. Nat. Générale des
Règnes Organiques, 1860. iii. 207 sq. BROCA: Mémoire sur
l’Hybridité, in Brown-Sequard's Journal de la Physiologie, 1859.
STUDIES IN ANIMAL LIFE.
161
One decisive case alone shall be given here, and
no one will dispute that it is decisive.
The hare (lepus timidus) is assuredly of a
distinct species from the rabbit (lepus cuniculus).
So distinct are these species, that any classification
which should range them as one, would violate
every accepted principle. The hare is solitary, the
rabbit gregarious; the hare lives on the surface of
the earth, the rabbit burrows under the surface;
the hare makes her home among the bushes, the
rabbit makes a sort of nest for her young in her
burrow-keeping them there till they are weaned;
the hare has reddish-brown flesh, the rabbit white
flesh; while the odour exhaled by each, and the
flavour of each, are unmistakeably different. The
hare has many anatomical characters differing from
those of the rabbit: such as greater length and
strength of the hind legs, larger body, shorter
intestine, thicker skin, firmer hair, and different
colour. The hare breeds only twice or thrice
a year, and at each litter has only two or four; the
rabbit will breed eight times a year, and each time
has four, six, seven, and even eight young ones,
11
162
STUDIES IN ANIMAL LIFE.
Finally, the two are violent foes: the rabbits
always destroy the hares, and all sportsmen are
aware that if the rabbits be suffered to multiply on
an estate, there will be small chance of hares.
Nevertheless, between species so distinct as these,
a new hybrid race has been reared by M. Rouy, of
Angoulême, who each year sends to market up-
wards of a thousand of his Leporides, as he calls
them. His object was primarily commercial, not
scientific. His experiments, extending from 1847
to the present time, have not only been of great
commercial value-introducing a new and valuable
breed-but have excited the attention of scientific
men, who are now availing themselves of his skill
and experience to help them in the solution of
minor problems. It is enough to note here, that
these hybrids of the hare and the rabbit are fertile,
not only with either hares or rabbits, but with each
other. Thirteen generations have already been
enumerated, and the last remains so vigorous that
no cessation whatever is to be anticipated.
In presence of this case (and others, though less
striking, might be named) there is but one alter-
STUDIES IN ANIMAL LIFE.
163
native; either we must declare that rabbits and
hares form one and the same species-which is
absurd-or we must admit that new types may
be formed by the union of two existing types; and
consequently that species are valuable. If the
docrine of Fixity of Species acknowledges the
touchstone of hybridity, the fate of the doctrine
is settled for ever.
he
Although I conceive the doctrine of Fixity of
Species to be altogether wrong, I cannot say that
the arguments adduced in favour of the develop-
ment hypothesis rise higher than a high degree
of probability, still very far from demonstration;
they will leave even the most willing disciple
beset with difficulties and doubts. When stated
in general terms, that hypothesis has a fascinating
symmetry and simplicity, but no sooner do we
apply it to particular cases, than a thick veil of
mystery descends, and our pathway becomes a
mere blind groping towards the light. There is
nothing but what is perfectly conceivable, and in
harmony with all analogies, in the idea of all
animal forms having arisen from successive modi-
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STUDIES IN ANIMAL LIFE.
fications of one original form; but there are many
things perfectly conceivable, which have neverthe-
less no existence; there are many explanations
perfectly probable, which are not true; and when
we come to seek for the evidence of the develop-
ment hypothesis, that evidence fails us. It may
be true, but we cannot say that it is true. Ten
years ago, I espoused the hypothesis, and believed
that it was the truth; but ten years of study,
instead of deepening, have loosened that convic-
tion: they have strengthened my opposition to
the hypothesis of fixity of species, but they have
given greater force to the difficulties which beset
the development hypothesis, and have made me
feel that at present the requisite evidence is
wanting. I conclude with reminding the reader
that the question of the origin of species is at
present incapable of a positive answer; of the
two hypotheses, that of development seems the
more harmonious with our knowledge; but it is
no more than an hypothesis, and will probably
for ever remain one. Now, an hypothesis,
although indispensable as a provisional mode of
STUDIES IN ANIMAL LIFE.
165
grouping together facts, and giving them some
sort of explanation, is after all only a guess, and
it
may be absurdly wide of the truth. In Natural
History, as in all other departments of specula-
tive ingenuity, there have been a goodly number
of outrageously extravagant hypotheses, gravely
propounded, and credulously accepted. Men prefer
an absurd guess to a blank; they would rather
have a false opinion than no opinion; and one
of the last developments of philosophic culture,
is the power of abstaining from forming an opinion,
where the necessary data are absent.
If you wish to see how easily hypotheses are
formed and accepted, you need only turn over
the history of any science. If you want a laugh
at credulity, read a chapter of Pliny's Natural
History. Pliny is a classic, and was for cen-
turies an authority; but looked at with impartial
eyes, he appears the veriest old woman
(C
that
ever wrote in a beautiful style. He was a mere
bookworm, without a particle of scientific insight.
His was not an age when men had much regard
to evidence; but to him the suspicion never seems
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STUDIES IN ANIMAL LIFE.
to have occurred that Gossip Report could be given
to romancing, or that travellers could "see strange
things." No fable is too monstrous for his cre-
dulity.
One of the pretty fables Pliny repeats, is, that
pearls are formed by drops of dew falling into
the gaping valves of the oyster. It never occurred
to him to ask whether oysters were ever exposed
to the dew? whether the drops could fall into their
valves? whether oysters kept their valves open,
except when under water? or, finally, whether,
if the dew did fall in, it would remain a rounded
drop? The drop of dew had a certain superficial
resemblance to the pearl, and that was enough.
Elian's hypothesis was somewhat better: he
supposed that the pearls were produced by light-
ning flashing into the open shells.
Turning from these ancient sages, you will ask
how pearls are formed? And almost any inge-
nious modern, not a zoologist, will tell you (and
tell you falsely), that the pearl is a disease of the
oyster. One is somewhat fatigued with the merci-
less frequency with which this notion has been
STUDIES IN ANIMAL LIFE.
167
dragged in, as an illustration of genius issuing
out of sorrow and adversity; and it is time to
stop that "damnable iteration" by discrediting
the notion. Know then, that if
"most wretched men
Are cradled into poetry by wrong :
They learn in suffering what they teach in
song
""
it is not true that oysters secrete in suffering what
women wear as necklaces. Disease would be the
very worst cradle for pearls. The idea of disease
originated in a fanciful supposition of pearls being
to the oyster and mussel what gall-stones and
urinary calculi are to higher and more suffering
animals. Réaumur, to whom we owe so many
good observations and suggestive ideas, came near
the truth when, in 1717, he showed that the
structure of pearls was identical with the structure
of the shells in which they grow. He attributed
their formation to the morbid effusion of coagula-
ting shell-material.
I presume you know that shells are formed by
a secretion from the mantle? The mantle is that
delicate semi-transparent membrane which you
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STUDIES IN ANIMAL LIFE.
observe, on opening a mussel or oyster, lining
the whole interior of the shells, and having at its
free margins a sort of fringe of delicate tentacles,
which are sensitive and retractile. A microscopic
examination of these fringes shows them to be
glandular in structure—that is, they are secreting
organs. The whole mantle, indeed, is a secreting
organ, and its secretion is the shell material: the
fringes secrete the colouring matters of the shell,
and enlarge its circumference; the rest of the
mantle secretes the nacre, or mother-of-pearl, and
increases the thickness of the shell. Now it is
obvious that the formation of pearl nacre, and of
pearls, depends on the healthy condition of the
mantle, not on its diseases. If the mantle be
injured the nacre is not secreted at all, or in less
quantities.
But although pearls depend upon the healthy, not
the diseased, activity of the mantle, it is clear that
there must be some unusual condition present for
their formation; since the secretion of nacre does
not spontaneously assume the form of pearls.
What is the unusual condition? Naturalists are
STUDIES IN ANIMAL LIFE.
169
at present divided into two camps, fighting vigor-
ously for victory. The one side maintains that the
origin of a pearl is this-an egg of the oyster has
escaped and strayed under the mantle; or the egg
of a parasite has been deposited there; this egg
forms the nucleus, round which the nacre forms,
and thus we have the pearl.
The other side maintains with great positiveness
that anything will form a nucleus, a grain of sand,
no less than the egg of a parasite. 'Tis a pretty
quarrel, which we may leave them to settle. Some
aver that grains of sand are more numerous than
anything else; but Möbius says that of forty-four
sea pearls, and fifteen fresh-water pearls, examined
by him, not one contained a grain of sand; and
Filippi, who has extensively investigated this sub-
ject, denies that a grain of sand ever forms the
nucleus of a true pearl. Both Filippi and Küchen-
meister declare that a parasite gets into the
mussel or oyster, and its presence there stimulates
an active secretion of nacre.
There are pearls, according to Möbius, which
* See their interesting essays in MÜLLER'S Archiv, 1856.
170
STUDIES IN ANIMAL LIFE.
consist of three different systems of layers, like the
shells in which they are formed; with this differ-
ence, that these layers are reversed in the shell
the nacre forms the innermost layer, in the
pearl it forms the outermost. Hence the quali-
ties of the pearl depend on the shell, and on the
different proportions of nacre and carbonate of
lime.
Since we know how pearls are made, may it not
be expected that we should learn to make them?
Ever since the days of Linnæus the hope has been
entertained, and it is now becoming every day more
likely to be realized. Imperfect pearls have been
made in abundance. The Chinese have long
practised the art. They simply remove the large
fresh-water mussel from the water, insert a foreign
substance under the mantle, and in two or three
years (if I remember rightly) they take the mussels
up again, and find the pearls formed. In this way
they make little mother-of-pearl Josses, which are
sold for a penny each; and I remember seeing a
couple of large shells in the Anatomical Museum at
Munich, the whole length of which was occupied by
STUDIES IN ANIMAL LIFE.
171
rows of little squab Josses, very comical to behold..
I was informed that a copper chain of these deities
had been inserted under the mollusc's mantle, and
this was the result.
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STUDIES IN ANIMAL LIFE.
CHAPTER VI.
Every organism a colony-What is a paradox ?—An organ is an
independent individual, and a dependent one-A branch of
coral-A colony of polypes-The Siphonophora-Universal
dependence-Youthful aspirings-Our interest in the youth of
great men-Genius and labour-Cuvier's college life; his
appearance in youth; his arrival in Paris-Cuvier and Geoffroy
St. Hilaire-Causes of Cuvier's success-One of his early
ambitions-M. le Baron-Omnia vincit labor-Conclusion.
THAT an animal Organism is made up of several
distinct organs, and these the more numerous in
proportion to the rank of the animal in the scale
of beings, is one those familiar facts which have
their significance concealed from us by familiarity.
But it is only necessary to express this fact in
language slightly altered, and to say that an
animal Organism is made up of several distinct
individuals, and our attention is at once arrested.
Doubtless, it has a paradoxical air to say so; but
Natural History is full of paradoxes; and you are
aware that a paradox is far from being necessarily
STUDIES IN ANIMAL LIFE.
173
an absurdity, as some inaccurate writers would
lead us to suppose: the word meaning simply,
"contrary to what is thought,"-a meaning by no
means equivalant to "contrary to what is the
fact." It is paradoxical to call an animal an
aggregate of individuals; but it is so because our
thoughts are not very precise on the subject of
individuality-one of the many abstractions which
remain extremely vague. To justify this applica-
tion of the word individual to every distinct organ,
would be difficult in ordinary speech, but in
philosophy there is ample warrant for it.
An organ, in the physiological sense, is an
instrument whereby certain functions are performed.
In the morphological sense, it arises in a differen-
tiation, or setting apart, of a particular portion of
the body for the performance of particular functions
-a group of cells, instead of being an exact repeti-
tion of all the other cells, takes on a difference, and
becomes distinguished from the rest as an organ.
Combining these two meanings, we have the
third, or philosophical sense of the word, which
* See on this point what was said in our first Chapter.
*
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STUDIES IN ANIMAL LIFE.
indicates that every organ is an individual exis-
tence, dependent more or less upon other organs
for its maintenance and activity, yet biologically
distinct. I do not mean that the heart will live
independent of the body, at least, not for long,
although it does continue to live and manifest
its vital activity for some time after the animal's
death; and, in the cold-blooded animals, even
after removal from the body. Nor do I mean that
the legs of an animal will manifest vivacity after
amputation: although even the legs of a man
are not dead for some time after amputation; and
the parts of some of the lower animals are often
vigorously independent. Thus I have had the
long tentacles of a Terebella (a marine worm)
living and wriggling for a whole week after ampu-
tation.*
In speaking of the independence of an organ,
I must be understood to mean a very dependent
independence because, strictly speaking, absolute
independence is nowhere to be found; and, in
* Seaside Studies, 2nd edit. p. 59, sq
STUDIES IN ANIMAL LIFE.
175
the case of an organ, it is of course dependent
on other organs for the securing, preparing, and dis-
tributing of its necessary nutriment. The tentacles
of my Terebella could find no nutriment, and they
perished from the want of it, as the Terebella
itself would have perished under like circum-
stances. The frog's heart now beating on our
table with such regular systole and diastole, as if
it were pumping the blood through the living
animal, gradually uses up all its force; and since
this force is not replaced, the beatings gradually
cease. A current of electricity will awaken its
activity, for a time; but, at last, every stimulus
will fail to elicit a response. The heart will then
be dead, and decomposition will begin.
Dependent, therefore, every organ must be on
some other organs. Let us see how it is also
independent; and for this purpose we glance, as
usual, at the simpler forms of Life to make the
lesson easier. Here is a branch of coral, which
you know to be in its living state a colony of
polypes. Each of these multitudinous polypes is
an individual, and each exactly resembles the
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STUDIES IN ANIMAL LIFE.
other. But the whole colony has one nutritive
fluid in common. They are all actively engaged
Fig. 20.

CAMPANULARIA (Magnified, and Natural Size).
in securing food, and the labours of each enrich
all. It is animal Socialism of the purest kind—
there are no rich and no poor, neither are there
any idlers.
Formerly, the coral-branch was regarded as one
STUDIES IN ANIMAL LIFE.
177
animal-an individual; and a tree was, and is,
commonly regarded as one plant-an individual.
But no zoologist now is unaware of the fact that
each polype on the branch is a distinct individual,
in spite of its connections with the rest; and
philosophic botanists are agreed that the tree is a
colony of individual plants—not one plant.
Letus pass from the coral to the stem of some other
polype, say a Campanularia. Here is (Fig. 20.) the
representation of such a stem, of the natural size,
and beside it a tiny twig much magnified. You
observe the ordinary polype issuing from one of
the capsules, and expanding its coronal of tentacles
in the water. The food it secures will pass along
the digestive tract to each of the other capsules.
Under the microscope, you may watch this oscilla-
tion of the food. But your eye detects a notice-
able difference between this polype in its capsule,
and the six semi-transparent masses in the second
capsule: although the two capsules are obviously
identical, they are not the same: a differentiation
has taken place. Perhaps you think that six
polypes are here crowding into one capsule ?
12
178
STUDIES IN ANIMAL LIFE.
Error! If you watch with patience, or if you are
impatient yet tolerably dexterous, you may press
these six masses out, and then will observe them
swim away, so many tiny jelly-fish. Not polypes
at all, but jelly-fish, are in this capsule: and these
in due time will produce polypes, like that one
now waving its tentacles.
Having made this observation, it will naturally
occur to you that the polype stem which bore such
different capsules as are represented by these two,
may perhaps be called a colony, but it is a colony of
different individuals. While they have all one skele-
ton in common, nutrition in common, and respira-
tion in common, they have at least one differentiation,
or setting apart for a particular purpose, and that is,
the reproductive capsule. This is an individual, as
much as any of the others, but it is an individual
that does nothing for the general good; it takes
upon itself the care of the race, and becomes an
organ" for the community; the others feed it,
and it is absolved from the labour of nutrition,
as much as the arm or the brain of a man are.
From this case, let us pass to the group of
STUDIES IN ANIMAL LIFE.
179
jelly-fish called Siphonophora (siphonbearers) by
naturalists, and we shall see this union of very
different individualities into one inseparable colony
still more strikingly exhibited: there are distinct
individuals to feed the colony, individuals to float
it through the water, individuals to act as feelers,
and to keep certain parts distended with fluid, and
finally reproductive individuals. All these are
identical in origin, and differ only by slight
differentiations.* Here we have obviously an
approach to the more complex organism in which
various distinct organs perform the several func-
tions; only no one calls the Organism a colony.
The individuals composing one of these Siphono-
phora are so manifestly analogous to organs, that
their individuality may, perhaps, be disputed, the
more so as they do not live separately. But the
gradations of separation are very fine. You would
never hesitate to call a bee, or an ant, an indivi-
dual, yet no bee or ant could exist if separated
* Compare LEUCKART: Ueber den Polymorphismus der Indivi-
duen. GEGENBAUR: Grundzüge der Vergleichende Anatomie;
and HUXLEY's splendid monograph on the Oceanic Hydrozca,
published by the Ray Society.
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130
STUDIES IN ANIMAL LIFE.
from its colony. So great is "the physiological
division of labour," which has taken place among
these insects, that one cannot get food, another
cannot feed itself, but it will fight for the com-
munity; another cannot work, but it will breed
for the community; another cannot breed, but
it will work. Each of these is little more than
separated organs of the great insect-Organism; as
the heart, stomach, and brain are united organs of
the human-Organism. Remove one of these
insects from the community, and it will soon
perish, for its life is bound up with the whole.
And so it is everywhere; the dependence is
universal:-
"Nothing in this world is single;
All things, by a law divine,
In one another's being mingle."
We are dependent on the air, the earth, the sun-
light, the flowers, the plants, the animals, and all
created things, directly or indirectly. Nor is the
moral dependence less than the physical.
cannot isolate ourselves if we would.
We
The
thoughts of others, the sympathies of others, the
STUDIES IN ANIMAL LIFE.
131
needs of others, these two make up our life;
without these we should quickly perish.
It was a dream of the youth Cuvier, that a
History of Nature might be written which would
systematically display this universal dependence.
I know few parts of biography so interesting as
those which show us great men in their early
aspirings, when dreams of achievements vaster
than the world has seen, fill their souls with
energy to achieve the something they do after-
wards achieve. It is, unhappily, too often but the
ambition of youth we have to contemplate; and
yet the knowledge that in after-life there came
less of hope, less of devotion, and less of generous
self-sacrifice, renders these early days doubly
interesting. Let the abatement of high hopes
come when it may, the existence of an aspiration
is itself important. I have been lately reading
over again the letters of Cuvier when an obscure
youth, and they have given me quite a new feeling
with regard to him.
There is a good reason why novels always end
with the marriage of the hero and heroine: our
182
STUDIES IN ANIMAL LIFE.
interest is always more excited by the struggles,
than by the results of victory. So long as the
lovers are unhappy, or apart, and are eager to
vanquish obstacles, our sympathy is active; but
no sooner are they happy, than we begin to look
elsewhere, for other strugglers on whom to bestow
our interest. It is the same with biography.
We follow the hero through the early years of
struggle with intense interest, and as long as he
remains unsuccessful, baffled by rivals or neglected
by the world, we stand by him and want him to
succeed; but the day after he is recognized by
the world our sympathy begins to slacken.
It is this which gives Cuvier's Letters to Pfaff*
their charm. I confess that, M. le Baron Cuvier,
administrator, politician, academician, professor,
dictator, has always had but a very tepid interest
for me; probably because his career early became
a continuous success, and Europe heaped rewards
upon him; whereas, his unsuccessful rival,
Geoffroy St. Hilaire, claims my sympathy to the
* Lettres de Georges Cuvier à C. M. Pfaff, 1788-92. Tra-
duites de l'Allemand, par Louis Marchant, 1858.
STUDIES IN ANIMAL LIFE.
183
close. If, however, M. le Baron is a somewhat
dim figure in my biographical gallery, it is far
otherwise with the youth Cuvier, as seen in his
letters; and, as at this present moment there is
nothing under our Microscope which can seduce
us from the pleasant volume, suppose we let our
“Studies" take a biographical direction.
"Genius," says Carlyle, "means transcendent
capacity for taking trouble, first of all." There
are many young gentlemen devoutly persuaded of
their own genius, and yet candidly avowing their
imperfect capacity for taking trouble, who will
vehemently protest against this doctrine. With-
out discussing it here, let us say that genius, or
no genius, success of any value is only to be
purchased by immense labour; and in science,
assuredly, no one will expect success without first
paying this price. In Cuvier's history may be
seen what "capacity for taking trouble" was
required before his success could be achieved; and
this gives these Lettres à Pfaff a moral as well as
an interest.
It was in the Rittersaal of the Academia
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STUDIES IN ANIMAL LIFE.
Carolina of Stuttgardt, and in 1787, that Pfaff,
the once famous supporter of Volta, first became
personally acquainted with him, his fellow-student
Cuvier. Although they had been three years
together at the same university, the classification
of students there adopted had prevented any
personal acquaintance. Pupils were admitted at
the age of nine, and commenced their studies with
the classic languages. Thence they passed to the
philosophical class, and from that they went to
one of the four faculties: Law, Medicine, Admi-
nistration, and Military Science. Each faculty,
of course, was kept distinct: and as Pfaff was
studying philosophy at the time Cuvier was
occupied with the administrative sciences, they
never met; the more so as the dormitories and
hours of recreation were different. The academy
was organized on military principle. The three
hundred students were divided into six classes,
two of which comprised the nobles, and the other
four the bourgeoisie. Each of these classes had
its own dormitory, and was placed under the
charge of a captain, a lieutenant, and two inferior
STUDIES IN ANIMAL LIFE.
185
officers.
These six classes in which the students
were entered according to their age, size, and time
of admission, were kept separate in their recrea-
tions, as in their studies. But those of the
students who particularly distinguished themselves
in the public examinations were raised to the rank
of knights, and had a dormitory to themselves,
besides dining at the same table with the young
princes who were then studying at the university.
Pfaff and Cuvier were raised to this dignity at the
same time, and here commenced their friendship.
What a charm there is in school friendships,
when youth is not less eager to communicate its
plans and hopes, than to believe in the plans and
hopes of others; when studies are pursued in
common, opinions frankly interchanged, and the
superiority of a friend is gladly acknowledged,
even becoming a source of pride, instead of being,
as in after years, a thorn in the side of friend-
ship! This charm was felt by Cuvier and Pfaff,
and a small circle of fellow-students who parti-
cularly devoted themselves to Natural History.
They formed themselves into a society, of which
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STUDIES IN ANIMAL LIFE.
Cuvier drew up the statutes and became the
president. They read memoirs, and discussed
discoveries with all the gravity of older societies,
and even published, among themselves, a sort of
Comptes Rendus. They made botanical, entomo-
logical, and geological excursions; and, still
further to stimulate their zeal, Cuvier instituted
an Order of Merit, painting the medallion himself:
it represented a star, with the portrait of Linnæus
in the centre, and between the rays various
treasures of the animal and vegetable world. And
do you think these boys were not proud when
their president awarded them this medal for some
happy observation of a new species, or some well-
considered essay on a scientific question ?
At this period, Cuvier's outward appearance was
as unlike M. le Baron, as the grub is unlike the
butterfly. Absorbed in his multifarious studies,
he was careless about disguising the want of
elegance in his aspect. His face was pale, very
thin, and long, covered with freckles, and encircled
by a shock of red hair. His physiognomy was
severe and melancholy. He never played at any
STUDIES IN ANIMAL LIFE.
187
of the boys' games, and seemed as insensible of all
that was going on around him as a somnambulist.
His eye seemed turned inwards; his thoughts
moved amid problems and abstractions. Nothing
could exceed the insatiable ardour of his intellect.
Besides his special administrative studies, he gave
himself to Botany, Zoology, Philosophy, Mathe-
matics, and the history of literature. No work
was too voluminous, or too heavy for him. He
was reading all day long, and a great part of the
night. "I remember well," says Pfaff, "how he
used to sit by my bedside going regularly through
Bayle's Dictionary. Falling asleep over my own
book, I used to awake, after an hour or two, and
find him motionless as a statue, bent over Bayle."
It was during these years that he laid the basis
of that extensive erudition which distinguished his
works in after life, and which is truly remarkable
when we reflect that Cuvier was not in the least
a bookworm, but was one of the most active
workers, drawing his knowledge of details from
direct inspection whenever it was possible, and not
from the reports of others. It was here also that
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he preluded to his success as a professor, astonish-
ing his friends and colleagues by the clearness of
his exposition, which he rendered still more
striking by his wonderful mastery with the pencil.
One may safely say that there are few talents
which are not available in Natural History; a
talent for drawing is pre-eminently useful, since
it not only enables a man to preserve observations
of fugitive appearances, but sharpens his faculty
of observation by the exercise it gives. Cuvier's
facile pencil was always employed: if he had
nothing to draw for his own memoirs, or those
of his colleagues, he amused himself with drawing
insects as presents to the young ladies of his
acquaintance—an entomologist's gallantry, which
never became more sentimental.
In 1788, that is in his nineteenth year, Cuvier
quitted Stuttgardt, and became tutor in a noble-
man's family in Normandy, where he remained
till 1795, when he was discovered by the Abbé
Tessier, who wrote to Parmentier, "I have just
found a pearl in the dunghill of Normandy;
to Jussieu he wrote-"Remember it was I who
#
STUDIES IN ANIMAL LIFE.
189
gave Delambre to the academy; in another depart-
ment this also will be a Delambre." Geoffroy
St. Hilaire, already professor at the Jardin des
Plantes, though younger than Cuvier, was shown
some of Cuvier's manuscripts, which filled him
with such enthusiasm that he wrote to him,
"Come and fill the place of Linnæus here;
come and be another legislator of natural history."
Cuvier came, and Geoffroy stood aside to let his
great rival be seen.
Goethe, as I have elsewhere remarked, has
noticed the curious coincidence of the three great
zoologists successively opening to their rivals the
path to distinction: Buffon called Daubenton to aid
him: Daubenton called Geoffroy, and Geoffroy
called Cuvier. Goethe further notices that there
was the same radical opposition in the tendencies
of Buffon and Daubenton as in those of Geoffroy
and Cuvier—the opposition of the synthetical and
the analytical mind. Yet this opposition did not
prevent mutual esteem and lasting regard. Geoffroy
and Cuvier were both young, and had in common
ambition, love of science, and the freshness of
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STUDIES IN ANIMAL LIFE.
unformed convictions. For, alas! it is unhappily
too true, that just as the free communicativeness
of youth gives place to the jealous reserve of
manhood, and the youth who would only be too
pleased to tell all his thoughts and all his dis-
coveries to a companion, would in after years let
his dearest friend first see a discovery in an official
publication; so, likewise, in the early days of
immature speculation, before convictions have
crystallized enough to present their sharp angles
of opposition, friends may discuss and interchange
ideas without temper. Geoffroy and Cuvier knew
no jealousy then. In after years it was otherwise.
Geoffroy had a position-he shared it with his
friend; he had books and collections-they were
open to his rival; he had a lodging in the museum
-it was shared between them. Daubenton, older
and more worldlywise, warned Geoffroy against
this zeal in fostering a formidable rival; and one
day placed before him a copy of Lafontaine open at
the fable of The Bitch and her Neighbour. But
Geoffroy was not to be daunted, and probably felt
himself strong enough to hold his own. And so
STUDIES IN ANIMAL LIFE.
191
the two happy, active youths pursued their studies
together, wrote memoirs conjointly, discussed,
dissected, speculated together, and "never sat
down to breakfast without having made a fresh
discovery," as Cuvier said, truly enough, for to
them every step taken was a discovery.
Cuvier became almost immediately famous on
his arrival at Paris, and his career henceforward
was one uninterrupted success. Those who wish
to gain some insight into the causes of this success
should read the letters to Pfaff, which indicate the
passionate patience of his studies during the years
1788-1795, passed in obscurity on the Norman coast.
Every animal he can lay hands on is dissected
with the greatest care, and drawings are made of
every detail of interest. Every work that is pub-
lished of any note in his way is read, analyzed,
and commented on. Lavoisier's new system of
chemistry finds in him an ardent disciple. Kiel-
meyer's lectures open new vistas to him. The
marvels of marine life, in those days so little
thought of, he studies with persevering minuteness,
and with admirable success. He dissects the
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cuttlefish, and makes his drawings of it with its
own ink. He notes minute characters with the
patience of a species-monger, whose sole ambition
is to affix his name to some trifling variation of
a common form; yet with this minuteness of detail
he unites the largeness of view necessary to a com-
parative anatomist.
"Your reflections on the differences between
animals and plants," he writes, in the passage
to which I previously referred, "will be the more
agreeable to me because I am at present working
out a new plan of a general natural history. I
think we ought carefully to seek out the relation
of all existences with the rest of nature, and above
all, to show their part in the economy of the
great All. In this work I should desire that the
investigator should start from the simplest things,
such as air and water, and after having spoken
of their influence on the whole, he should pass
gradually to the compound minerals, from these
to plants, and so on; and that at each stage he
should ascertain the exact degree of composition,
or, which is the same thing, the number of
STUDIES IN ANIMAL LIFE.
193
properties it presents over and above those of the
preceding stage, the necessary effects of these
properties, and their usefulness in creation. Such
a work is yet to be executed. The two works of
Aristotle, De Historia Animalium, and De
Partibus Animalium, which I admire more each
time that I read them, contain a part of what I
desire, namely, the comparison of species, and
many of the general results. It is, indeed, the
first scientific essay at a natural history. For this
reason it is necessarily incomplete, contains many
inaccuracies, and is too far removed from a know-
ledge of physical laws." He passes on from
Aristotle to Pliny, Theophrastus, Discorides,
Aldovrandus, Gesner, Gaspar Bauhin, and Ray,
rapidly sketching the history of natural history as
a science; and concluding with this criticism on
these attempts at a nomenclature which neglected
real science :-"These are the dictionaries of
natural history; but when will the language be
spoken ?"
No one who reads these letters attentively, will
be surprised at the young Cuvier's taking eminent
13
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STUDIES IN ANIMAL LIFE.
rank among the men of science in France; and
Pfaff, on arriving in Paris six years afterwards,
found his old fellow-student had become "a
personage." The change in Cuvier's appearance
was very striking. He was then at his maturity,
and might pass for a handsome man. His shock
of red hair was now cut and trimmed in Parisian
style; his countenance beamed with health and
satisfaction; his expression was lively and
engaging; and although the slight tinge of
melancholy which was natural to him had not
wholly disappeared, yet the fire and vivacity of his
genius overcame it. His dress was that of the
fashion of the day, not without a little affectation.
Yet his life was simple, and wholly devoted to
science. He had a lodging in the Jardin des
Plantes, and was waited on by an old housekeeper,
like any other simple professor.
On Pfaff's subsequent visit, things were changed.
Instead of the old housekeeper, the door was
opened by a lackey in grand livery. Instead of
asking for "Citizen Cuvier," he inquired for
Monsieur Cuvier; whereupon, the lackey politely
STUDIES IN ANIMAL LIFE.
195
asked, whether he wished to see M. le Baron
Cuvier, or M. Frédéric, his brother? "I soon
"It was
found where I was," continues Pfaff.
the baron, separated from me by that immense
interval of thirty years, and by those high dignities
which an empire offers to the ambition of men."
He found the baron almost exclusively interested
in politics, and scarcely giving a thought to
science. The "preparations
preparations" and "injections
which Pfaff had brought with him from Germany,
as a present to Cuvier, were scarcely looked at,
and were set aside with an indifferent "that's
good," and "very fine; " much to Pfaff's distress,
who doubtless thought the fate of the Martignac
ministry an extremely small subject of interest
compared with these injections of the lymphatics.
But it is not my purpose to paint Cuvier in his
later years. It is to the studies of his youth that
I would call your attention, to read there, once
again, the important lesson that nothing of any
solid value can be achieved without entire devo-
tion. Nothing is earned without sweat of the
brow. Even the artist must labour intensely.
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STUDIES IN ANIMAL LIFE.
What is called "inspiration" will create no works,
but only irradiate works with felicitous flashes;
and even inspiration mostly comes in moments of
exaltation produced by intense work of the mind.
In science, incessant and enlightened labour is
necessary, even to the smallest success. Labour
is not all; but without it, genius is nothing.
THE END.
LONDON: Printed by SMITH, ELDER & Co, 15, Old Bailey, E.C.


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