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STUDIES IN THE EVOLUTION OF ANIMALS
‘The best that you can do is to write the book that it gives you the most pleasure to_
write, to put as much heart and soul as you have about you into it, and then hope as
hard as you can to reach the heart and soul of the great multitude of your fellow-men.’

ane Man of Letters as a Man of Business, by W. D. HOWELLS,
Serdbner’s Magazine, October 1893.
“STUDIES IN THE
EVOLUTION OF ANIMALS

BY

al
EY BONAVIA, M.D.

BRIGADE SURGEON I.M.D.

AUTHOR OF ‘THE CULTIVATED ORANGES AND LEMONS
OF INDIA AND CEYLON,’ ‘PHILOSOPHICAL NOTES ON
BOTANICAL SUBJECTS,’ ‘THE FLORA OF THE ASSYRIAN

: MONUMENTS AND ITS OUTCOMES”

WITH ONE HUNDRED AND TWENTY-EIGHT ILLUSTRATIONS

Westminster
ARCHIBALD CONSTABLE AND COMPANY
PUBLISHERS TO THE INDIA OFFICE
14 PARLIAMENT STREET, S.W.

MDCCCKCV

(Al Rights reserved] cm

BY
d

Edinburgh: T. and A. ConsTaBLk, Printers to Her Majesty
CONTENTS

PREFACE,

INTRODUCTION,

PART 1.—Spotted and Striped Mammals (Horses excepted),

”

”

”

”

”

11.—Dappled and Striped Horses, and some other Mammals,
111.—Meaning of the Jaguar and Leopard Rosettes, and of the
markings of other Mammals,
1v.—Further evidence in support of the theory that existing Mam-
mals descended from carapaced ancestors,
v.—Researches and discussions to connect, more surely, Armour-
plating with Skin-picturing,
vi.—Probable meaning of some interesting features in Horses and
other animals,
vil.—Is Natural Selection the sole factor in the Coloration of

Mammals ?

», VIII.—Probable cause of the loss of the Calcareous Armour in

”

Mammals,
1x.—Relationship between the Armadillo, the Rhinoceros, the

Horse, the Giraffe, and the Zebu,

PAGE

vil

xv

57

99

135

153

165

189

199
vi STUDIES IN THE EVOLUTION OF ANIMALS

Part X—Explanation of the Callosities on the Legs of Equine Animals
and others,
» XI.—The One Big Digit of the Horse,
.. XIl.—Monstrosities as probable factors in the creation of species, .
GENERAL CONCLUSIONS,

APPENDICES,

PAGE

331
PREFACE
Of what value would the objective facts a/ove have been, even if they were collected
by millions, without a colligating theory which puts sov/ into the scattered facts? They
would be as soulless as heaps of bricks and mortar are before they are built up into
a Cathedral. Theory founded on facts, as it should be, is of the greatest importance in
forming a right conception of Nature. Theories cannot flash out in all perfection.
They require to be mended, and time is needed for that.
PREFACE

THE genesis of these studies was the following :—

Having completed the Flora of the Assyrian Monuments and tts
Outcomes, 1 was looking about for something to take up next as a
subject of study. In the furriers’ windows I was attracted by the
Leopard and Tiger skins, which by degrees became objects of
interesting study and speculation.

Thinking over the rosettes of the Leopards, and more especially
those of the Jaguar, and seeing spotted Horses constantly in the
streets of London, some new ideas flashed across my mind
regarding the origin of all this spotting and rosetting in
mammals.

Keeping ‘my eyes open,’ so as to get some insight into the
invisible, and making many researches for some tangible facts
which would serve as a basis for my speculations, the subjects
of the curious callosities on the legs of the Horse, its solitary big
digit, its possible close relationship to the pair of digits in
the ruminants, and various monstrosities, came under review, as
well as several other collateral points, and so, each group, as it
became interesting, was worked up into a separate study, followed
up by that on the meaning of the rosettes on the Jaguar and allied
animals, and of the dapples which are all but universal in Horses
x STUDIES IN THE EVOLUTION OF ANIMALS

—whether as a completely dappled surface, or as vestiges of an
extensively spotted skin, Spotting and striping in mammals, or
vestiges of such markings, are to be met with so extensively among
these animals, that I came to the conclusion they must have a
deeper meaning than may have hitherto been attributed to them
by evolutionists.

The reader should understand that a book like this is not written
as a poem might be written, by sitting down in some suggestive
surrounding, gazing into space, and letting the thoughts come
rambling after each other, as if by inspiration.

Not a few perhaps may think that the author just sat down and
wrote it off! Few would consider what interminable searching for
authorities was needed; what hunting for facts and evidence to
build upon; what hunting for suitable skins and animals to be
photographed, and for photographs of animals to be used as
illustrations, were required. Nowadays, one might as well speak
to the wind as produce a book of this sort without numerous
illustrations. The vaiue of an illustration is that it appeals to the
mind at once, while a string of words used in a description, without
an illustration, would only, in most cases, fatigue the reader’s mind,
and leave little or no impression. Everything must be made as easy
as possible for the student and general reader, otherwise he or she
will turn to something else. There is too much to distract the
attention from making a serious effort to comprehend even a small
portion of the work of creation. Moreover, this is the age of maga-
zines, which mean a conglomerate, and most people prefer that.

The arrangement of notes taken at all sorts of odd times

and places; the digesting and comparing of points, writing out
PREFACE xl

notions, tearing them up, and re-writing them, and a hundred other
troubles, would all have been the most wearisome work had it not
been backed by the stimulus and enthusiasm roused by the convic-
tion that there was something interesting to be told. If the reader
should feel a hundredth part of the interest, in reading these pages,
that I felt in writing them, I am sure he ought to be a happy
individual.

In these pages there may be some things which scientists may
have either overlooked as unimportant, or which they may not
have cared to tackle, appearing to them as insoluble.

I have also attempted to develop particular points in the sub-
theories of the more general theory or doctrine of evolution. As
Professor Huxley is stated to have declared at Oxford not long
ago,' even if Darwinism were swept away it would leave evolution
untouched. The doctrine of ‘creation by the method of evolution ’
has replaced all other doctrines, and it cannot be upset by mortals,
for it is based on the every-day experience that a mother pro-
creates children, and these other children, and these others, and
so forth No one yet has even attempted to upset shat fact
of nature.

The study of the coloration of mammals is an intricate one ;
and in the various .parts of this discussion repetitions could
hardly be avoided; but although wearisome to the expert, the
general reader, who may not be very conversant with the facts
of evolution and natural selection—should he care to study this
part of modern philosophy—may derive benefit from these

1 After the Inaugural Address of Lord Salisbury to the British Association,
8th August 1894.
xii STUDIES IN THE EVOLUTION OF ANIMALS

unavoidable though wearisome repetitions. Moreover, I am not
aware that there is any particular sin in a little repetition. The
reader after all is not so sacred a thing as not to be subjected
on any account to a little tedium. Some little allowance then,
I suppose, may be made for the ‘personal equation’ of the
writer !

I do not know a better method for fixing notions on the
reader’s convolutions—more especially if he or she is not easily
convinced—than by ‘hammering’ on the same subject in different
ways, in order to make an impression. Few people who may
be tempted to open a book do so with the spirit of the student
who endeavours to master the meaning and points therein
contained. The majority of persons who take up a book want
to be amused, distracted, or somehow entertained, and few are
the books on evolutionary studies which can satisfy either of
these cravings.

Inferences cannot be safely drawn from any particular speci-
men ; the larger the number of specimens on which an inference
is based, the more soundness will it be likely to possess.

Where too much detail might seem tedious to the expert,
I would note that it is intended for the general reader who may
be tempted to dip into these subjects, and who may not have
given much attention to such matters.

If found tedious, whole pages may be skipped by the expert.

I believe that this is the first time that any attempt has been
made to study the markings of mammals in de¢az/, with the
view of reaching what seems to be the real, or at all events the
proximate, cause of their existence. Mr. Tylor and Mr. Poulton,
PREFACE xiii

Dr. Wallace and Mr. Darwin have studied the coloration of
animals ; but, as far as I am aware, no attempt has been hitherto
made to account for certain markings which occur, as one might
say, in a sort of fam, and in so many different animals. In
these pages I have made an attempt to account, not only for
their derivation, but also for their genesis, as far as this can
be known.

I need hardly mention that the figures of Horses were not
selected for their beauty of outline, but for their dappling. Most
of the outline drawings are reduced in size.

My thanks are due to Professor J. M‘Fadyean and Mr. P.
D. Coghill of the Royal Veterinary College, for helping me with
photographs of Horses; and to Mr. James Poynter of the Horse
department of the Great Northern Railway, and Mr. William
D. Duff, manager of the London Road Car Company, for their
kind permission to photograph some of the horses in the stables
of their companies. I have to thank also Messrs. Jeffs and
Harris, and Messrs. Back and Co., of Regent Street, for allowing
me to have some of the skins in their stores photographed.
Finally, my thanks are due to Miss Butcher for numerous out-
line drawings of mammals, etc., in the Natural History Museum.
Some apology is, I think, due to her for asking her to make
drawings of those archeological exhibitions of Taxidermy. As
she remarked, it was difficult to know where their legs ought to
be! The recent specimens in that museum are, however, splendidly
got up.

E. BONAVIA.
INTRODUCTION
‘Evolution is the most striking feature of modern scientific thought, hence all that
terms itself evolution must be scientific—such seems to be the logic of the average
reviewer, and, we regret to say it, of some men of science who ought to know better.
The fact is that the word ‘‘ evolution” has been so terribly abused, first by the biologists,
then by pseudo-scientists, and lastly by the public, that it has become a cant term to
cover any muddle-headed reasoning, which would utterly fail to justify itself had it
condescended to apply the rule of three. A variety of ill-described and ill-appreciated
factors of change have all been classed together and entitled the theory of evolution.’

Socialism and Natural Selection, by KARL PEARSON,
Fortnightly Review, July 1894, p. I.
INTRODUCTION

‘Ir is not enough that a scientific truth should be the possession of a privileged
few; those who value the truth should try to spread it, and make it common
intellectual property, and this can only be done when. they realise that simplicity
of language, and correct style, and a good arrangement, are essential to its
propagation.’

‘The British Association,’ Mature, 16th August 1894.

ANY one who may think of devoting his attention to the study of
the philosophy of life, based, not only on the materials he has
himself observed and discovered, but also on those worked up by
others, is met, at the outset, with a huge mountain of words.
‘Words will govern us, if we do not govern them,’ said Professor
Max Miiller. Any one who tries to get at the bottom of facts, and at
the bottom of the inferences resulting from those facts, has to grope
his way through this maze of often utterly useless, if not mis-
chievous, terminology. The essential truth may be obscured
by the novel and difficult-to-be-remembered wording ; so that we
often ‘cannot see the wood for the trees.’

By way of introduction to the introduction, let us take a glance
at what even leading scientists think of it all. If scientific men
complain of the nuisance, what would you say the man in the
street would think of it?

M. L. Guinard in his Précts de Tératologie, p.xvi., gives expres-
sion to the feeling of distress caused by hasty and reckless additions
to modern scientific nomenclature. He says: ‘La multiplication
des termes aurait fatalement la méme conséquence que la multi-

b
xviii STUDIES IN THE EVOLUTION OF ANIMALS

plication des langues; celui qui songera a jeter les bases d’un
édifice taxonomique par trop nouveau aboutira a I’édification d’une
tour de Babel.

‘Si j’insiste sur cette particularité, c'est que moi-méme j'ai été
souvent embarrassé par la diversité de noms et des classifications, et
parce que actuellement, on voit la tendence dont je parle persister
encore dans quelques travaux fort remarquables d’ailleurs.’

Then Mr. Stebbing, in his interesting work on the Crustacea,
p. 255, referring to Mr. Spence Bates’ ‘Report on the Challenger
Macrura,; says, ‘But simplicity seems to be the very last thing
considered in Spence Bates’ terminology, and though such words
as phymacerite, psalistoma, and stylamblys, may help to curtail
the length of descriptions, they are only too likely also to curtail
the number of those that read them.’

And certainly this is one of the mischiefs wrought by unneces-
sary coining of new terms to express ideas which might in many
cases be conveyed in ordinary wording.

Very recently another note of warning has been sounded in
Natural Science of October 1893, under the heading of ‘ Scientific
Linguistics’: ‘When a layman asks a naturalist why he invents
and employs such a multitude of incomprehensible technical terms,
the common reply is that exact ideas necessitate a precise and
universally (!) understood nomenclature. We wonder how this
explanation would apply to the terms of “ Auxology,” or “ Bioplast-
ology,” just discussed by Professor A. Hyatt in the Zoologischer
Anzeiger (concluded August 28, 1893). We should like to know
how much scientific precision there is in the determination of the
nepionic, metanepionic, gerontic, paragerontic, etc., stages of any
organism, and what grain of solid fact,as compared with mere specu-
lation, in the so-called definition of the phylonepionic, phyloneanic,
phylogerontic, etc., phases of development in any group of animals.
INTRODUCTION XIX

We may be enslaved by some prejudice, and our patience may
have been ruffled in the attempt to decipher some recent writings
of American authors on fossil shells; but we cannot help uttering
a protest against the clothing of a tissue of hypothetical fabrications
in a garb of a precisely-defined scientific nomenclature.’

In a note to p. 1366, Nicholson and Lydekker! complain of
the same trouble. Regarding the genera of Rhinoceroses of the
American school, they say :

‘From the writers’ point of view the multiplication of generic
terms, which, as our knowledge advances, must become less and
less susceptible of exact definition, tends to drown the science in a
sea of names, which form a great burden to the memory, and thus
tend to destroy the very object of classification.’

Classification is not the exd of a science, but the means of
facilitating the conception of creation by the method of evolution ;
and if the whole conception be obscured under a heap of names, its
object will be surely defeated.

‘La haute science’ would appear to consist now in the faculty
of inventing such names as the following :—‘ids, ‘idants,’ ‘idio-
plasm, ‘somatic idio-plasm, ‘morpho-plasm,’ ‘apical-plasm, as
composing the ‘sphere’ of germ-plasm, and which the late
Professor Romanes? compared to the nine circles of Dante’s
L[nferno!' :

I ask again, if scientists are groaning under the grip of this
‘demon’ of chaotic modern nomenclature, what should the poor
beginner say, who would have to commit to memory such an
amount of useless terms before he can understand what the
professor is talking about. All this needless multiplication of
terms is worrying and distressing to the ‘grey matter’ of the brain

1 Manual of Paleontology. 2 Examination of Weismannism, p. 118.
XX STUDIES IN THE EVOLUTION OF ANIMALS

of both professor and student, and to all earnest investigators, who
wish to get to the bottom of creation by the method of evolution.
As to the general reader, he may probably say: ‘Non ragioniam
di lor, guarda e passa.’

This troublesome multiplicity of useless words has certainly
become a formidable difficulty to those who may wish to pursue
scientific investigations, and an obstruction to the progress of
Science ; for if, before attempting to devote one’s time to the study
of the ‘ Philosophy of the Sciences, one has to learn a language as
difficult as that of cuneiform inscriptions, it will deter many from
embarking in such a pursuit.

Is it any wonder that ordinary people do not think that
scientific men are either so sensible and unselfish as they may think
themselves to be? The curious part is that tyros may perhaps think
that these strange and unpronounceable words are /He science, and
may startle their friends with the extent of scientific knowledge
they have acquired at the schools, colleges, or universities !

Are then the facts of the universe, and the discoveries made by
scientific explorers, to remain the possession of the few, by being
locked up in a language which only means ‘hieroglyphics’ to
most ordinary men and women?

It is truly touching to contemplate the helplessness of the
human mind in face of the prodigious number of variations it
has to deal with in studying organic forms.

Mr. Stebbing, in the before-mentioned work, p. 43, says: ‘It
may here be mentioned that the full number of joints for a
malacostracean trunk leg is seven. The afflicted naturalist has for
many years had to deal with these seven under the following
names, coxa, basis, ischium, merus, carpus, propodus, dactylus,
which respectively signify hip, foot, socket of thigh joint, wrist,
forefoot, and finger or toe.
INTRODUCTION Xxi

‘Originally the names were longer, all being podites, from
coxopodite to dactylopodite ; to the use of these the philosophic
French still adhere, though the time-saving Anglo-Saxon has
for the most part rejected them! . . . The more reasonable plan is
now to denote them by means.of figures from first joint to seventh
joint.’

As the antennz of the Lobster are homologous with podzites, it is
a wonder that a hundred names had not been invented to designate '
their hundred or more distinct joints. Why not have had also
a separate name for each hair on a man’s head?!

The followers of Galileo have had their revenge by pointing
out the innumerable absurdities of the teachings of the Church ;
but the turn of the Church may come, and it may have z¢s revenge!

The mischief of all this is that the mass of mankind, even
in the most civilised countries, both men and women, are wholly
zgnorant of the simplest facts of creation, and all these unnecessary
difficulties only increase their reluctance to have anything to
do with the wonders of nature.

The craving for coining new words at every turn has already
landed us in a sort of mental chaos, and earnest thinkers see that
no advantage can come from this bewildering multiplicity of terms
towards a simplification of science. It only burdens the memory of
those who may be courageous enough to follow scientific pursuits,
without in the least making things clearer.

Mr. James Geikie! says: ‘When I] attended school, the text-
books used by my teachers were about as repellent as they
could be,’

And at p. 12: ‘Great care, however, should be taken to avoid
wearying the youthful student with strings of mere names.’

When we find professors making fun of this so-called scientific

1 Fragments of Earth Lore, p. 1.
Xxli STUDIES IN THE EVOLUTION OF ANIMALS

terminology, we begin to hope that the tide may turn, and that we
and future generations may yet be released from the mockery
which some may think a good substitute for science.

The pursuits of the specialists no doubt were a great induce-
ment to coining new names for every cell, for every joint, for
every limb of a Milliped, and so forth. This, however, is what Dr.
Burdon Sanderson has said, in his inaugural address to the British
' Association in 1893: Specialism advances knowledge at the risk of
deteriorating the man, and tends to exaggerate the importance of
one set of phenomena, simply because the bearing of another
set is not seen in the course of that division of labour.

Taking a philosophical view of any set of phenomena does not
mean that you have never attended to detail by close inspection ;
but it means that you are able to withdraw your mind to a distance
from the detail, and so take a broader view of the whole landscape,
so as to include more of creation at one time, and thus obtain
a comprehensive view of the relativity of the detail.

John Hunter said—‘ Don’t think, try. He however not only
tried, but also thought. The bane of modern life seems to be that
there is too much trying, and very little thinking of what may
happen! We should now say— Think, investigate, imagine, and
also try. And when you get an idea into your head follow it up.
If it is worth anything, and if it has any truth in it, and zf you get
rid of your mental inertia, and keep your eyes and ears open, you will be
sure sooner or later to come across evidence in support of your idea.
You have also of course to read and ascertain, if you can, what
others have thought and have written on the same set of subjects.
These are all various ways of ascertaining the truth, and of making
sure that it zs truth you are dealing with.

We have been for centuries ‘hag ridden’ by monstrous fictions,
and it is certainly a comfort to emerge from the pressure of this
INTRODUCTION xxiii

deep sea of unrealities, and take a look round upon the upper
world of realities.

At the back of the phenomenon we call a Horse, a Cat, or any
other animal, there is a whole chain of phenomena—its evolution
—which in ancient time was not suspected. All this chain of
phenomena, leading up to what you actually see, has to be dis-
covered by the aid of the imagination, which does not a/ways tell
the truth.

Without a free use of the imagination a dog is a dog, a cat is
a cat, a cloud is a cloud, and nothing more. They are facts, like
so many soldiers scattered on a field of battle without discipline
or organisation. The function of the imagination is to group these
scattered units into companies, regiments, and armies, and fight
imaginary battles with them, all manceuvred by a general called
‘Logic,’ who has his eyes open, and insight to discover what is
going on around him. What this general has to be particularly
careful about is, not to let his imagination wander loosely, and see
all sorts of things that are not justified by ascertained facts.

Some persons pride themselves upon not possessing any power
of imagination, as if it were so very meritorious a feature of their
‘grey matter. They say they deal exclusively with facts. They
do not, however, see that through this deficiency they lose that
insight which is the work of what we call the imagination, and so
they fail to notice what is behind the facts. They may perhaps
not be aware that a great deal of the charm of life consists in
possessing a vivid imagination, provided the possessor of it is able
to keep it under control. By this faculty we are enabled, in a way,
to picture what would otherwise be a wholly invisible past world.
To exercise the imaginative power is to cultivate a most useful

implement of research.
There is so much to learn in one’s short life. Every branch of
Xxiv STUDIES IN THE EVOLUTION OF ANIMALS

Science is being studied with such minuteness that the help of the
imagination is largely needed, not only to understand the pheno-
mena yourself, but to make them clear to the imagination of other
people. But note this: the grey matter of the human brain is a
very treacherous informer. It invents a lot of things which it
preaches unhesitatingly as truths, and then, after-generations have
the task of sifting the whole, and re-classifying the supposed
phenomena into truths, sub-truths, and lies!

In the course of these pages I have mentioned that the colora-
tion of the skin of animals may have been greatly influenced by the
electricity of the brain-cells. You might naturally ask—What has
electricity to do with the colouring of animals? But just think of
it, and tell me where electricity does zo¢ come in. The modern
view of electricity is that you cannot touch anything, you cannot
move anything, you yourself cannot move, or cannot think, or
will, without the evolution of electricity. If I blow on my hand,
the impression on my skin is electrical, and is conveyed through
my nerves to my brain, and there either develops thought, or both
thought and action.

One should have heard Professor Oliver Lodge on the evening
of the 1st June 1894,! at the Royal Institution, and have seen him
make experiments to illustrate the Hertz waves, in order to realise
how completely the nerve-centres of animals are in the grip of
their surroundings, taking of course the visceral impressions as
part of the surroundings. Just as one Leyden jar in action influ-
ences another wholly disconnected with it, except through the
means of the ether, but attuned to it, and sets it in motion ; just
as one tuning fork in vibration sets another in action which is in
unison with it; just as one magnet influences another near it, so
everything—light, heat, magnetism, electricity, gravity, etc., act on

} Lecture printed in Matere of 7th June 1894, p. 133.
INTRODUCTION: ~ xxv

the sensitive nerve-matter of the nervous system of animals, and
influence thought and all other nerve-action.

Several branches of animals evolved from other animals which
were not stationary, but were changing. While changing, they in
turn were evolving others in various ‘ grooves’ of evolution. This
would account for the fact that although their descendants have
several characters in common with the ancestral stock, they are
nevertheless widely distinct in other characters ; and the characters
they mostly differed in were exactly those which depended on the
influences of surroundings for their development, and therefore
were greatly modified by them.

There is another point about which zoologists seem to have xo
doubt.

Mr. Herbert Spencer! says: ‘Zoologists are agreed that the
Whale has been evolved from a mammal which took to aquatic
habits, and that its disused hind-limbs have gradually disappeared,’

Many others have also the same belief; for Mr. Hutchinson ?
says: ‘Take for example the case of Whales and fishes; the
original land mammal from which Whales are descended has in
course of time become so fish-like in appearance that even in these
modern days there’ are some who yet speak of them as fishes!
The shape of the Whale is fish-like; it has lost its hind-limbs
through disuse: it has changed its fore-limbs into paddles, which
have a certain fin-like aspect; and its cousin, the Porpoise, has
developed a big triangular fin on the back.’

All this derivation of water mammals from /avd mammals alone
may be true or wzntrue, In the words of Mr. Hutchinson: ‘What
right has any one, however great his knowledge or his ability, to
dictate to Nature, and to say this or that is impossible?’

1 “Rejoinder to Professor Weismann,’ Contemporary Review, December 1893, p. 909.
2 Creatures of Other Days, p. 131.
XXVi STUDIES IN THE EVOLUTION OF ANIMALS

I confess that this theory which considers the fish-like mammals
as having descended from land mammals which took to aquatic
habits does not seem to me satisfactory. Zoologists would appear
to have conceived a roundabout way of evolving a Whale. The
fish is made first to evolve a land mammal, and then this takes to
the water again and gets rid of its hind-legs. It seems clear to me
that if the fish proper could evolve a /and mammal, it could also
evolve a water mammal, without the necessity of going through this
roundabout performance. If a bird could lose its fore-limbs on
land, it would appear that a Whale could lose its hind-limbs in the
water.

This notion presupposes the possibility of /azd mammals
evolving from fishes, and the impossibility of water mammals
evolving from the same fishes. And all this in face of all we know
about the Ichthyosaurs and Plesiosaurs, with their dwindling hind-
limbs ; in face of the shore and land fishes hopping about on their
pectoral fins on land, so that they are difficult to catch; in face of
the fact that certain fishes proper can breathe either by gills or by
lungs, according to circumstances ; and in face of the fact, which
every one knows, that the Tadpole is first fish-like, and then evolves
arms and legs wethout getting out of the water.

Are we so sure, in spite of ‘agreement among zoologists,’ that
the Whales are degenerated /and animals, and that land animals are
not further evolutions of fish-like animals which have taken to life
on dry land, while the Whale, evolving from the same fish-plane,
remained a water mammal ?

In the amphibians alone we have ample evidence that a fish-
like vertebrate can grow arms and legs w7thout leaving the water ;
and in the Ichthyosaurs we have again ample evidence that the
hind-limbs were already undergoing degradation, and that in the
Plesiosaurs both the hand and foot had become degraded to
INTRODUCTION xxvii

five digits, instead of the many digits of the Ichthyosaur form. I
think no one has ever credited these extinct animals with having
been first land animals which took to a water life. There is, more-
over, some evidence in favour of considering them mammals.

Professors and authors would seem to have stereotyped on our
brain the words ‘normality,’ ‘anomaly,’ ‘monstrosity, giving them
certain arbitrary meanings. They perhaps may have thought that
they. had settled all matters regarding creation, as far as such
phenomena were concerned. But let us imagine that anomalies
and monstrosities may possibly have been ‘factors in the origin of
species. Then we begin to see that the method of creation will
appear under a somewhat different aspect from what books and
professors have taught us.

Under the heading of ‘ Monstrosities,’ I have discussed these
particular phenomena, and have endeavoured to show that what
we call monstrosities may have been more frequent factors in
modifying the structure of animals than has been supposed.

As the whole arm can be suppressed in one birth, so, I imagine,
could the Archeopteryx have had its long tail shortened to the
little stump of the modern bird in ove birth. The objection to
such a sudden transformation seems to rest only in the minds of
those who have worked up into an wxalterable dogma the notion
that modifications in organisms are brought about solely by slow
degrees. This dogma may possess no unalterability owts¢de the
brain of scientists.

It might be said, if this were so, the long tail of the Archeo-
pteryx would have revealed itself sometime by a sudden reversion.
But reversions in some organisms either rarely happen, or do not
happen at all, and if they do happen, sometimes they may escape

notice.
For instance, no botanist doubts that the leaf of the orange and
XXViil STUDIES IN THE EVOLUTION OF ANIMALS

lemon trees is the middle leaflet of some ancestral form with ¢hree
leaflets, like that of Citrus Trifoliata} yet the one leaflet persists
through millions of generations without reversions. In India, in
my researches on the oranges and lemons, I sowed seeds of all
kinds of Citrus, and only a few seedlings gave any indication in
their firs¢ leaves of having descended from a trifoliate ancestor.’

Evolutionists do not believe that modern birds evolved from
the extinct Pterodactyle form. Yet what is more easy than for a
pterodactyle wing-membrane to grow fair, like other parts of the
body ; and for this to become exaggerated into feather-like hairs,
and soon ; then for the wing-membrane to contract, perhaps even in
one generation, so as to envelop the arm and finger-bones, while the
feathers increased in size, and became the veal flying apparatus ?

All this seems certainly preposterous and fanciful to a person
who may have looked upon monstrosities as ungodly phenomena,
but as they do occur now, there is no reason to suppose they did
not occur in past ages.

The animal congenitally is given a certain bodily structure
whether normal or abnormal.

He, that is, his nerve-centres, must make the best of it, if he is
to live atall. He has, moreover, to regulate his actions and habits
by the growing structure of which he is possessed, until they
become established by the completion of that growth in adult age.
He is the sport of inheritance and surroundings. Inheritance
tends to keep him on certain more or less fixed lines, but it does
not at all follow that circumstances may not change his structure
to a /arge extent in one birth, so as to shunt his descendants on to
a new line.

We know that all mammals are allied, for if they were not,

1 See Gardeners’ Chronicle of 18th November 1893, p. 625.
* See Oranges and Lemons of India and Ceylon, pl. 246.
INTRODUCTION xxix

they would not have the same plan of skeleton, and the same
apparatus for nursing their young.

Besides nervous, circulatory, and other structural features, which
mammals have also in common, there are dermic features which, I
think, have not been hitherto sufficiently recognised by biologists
as indications of derivation. I mean the markings on the exterior
of mammals. Of course every one knows that Leopards and
Spotted Cats are allied, but probably few suspect that the spots
on Leopards may indicate a distinct derivation from animals
which have no spots. I don’t mean with Lions and Pumas and
other individuals of the Cat tribe, but with animals wholly distinct
from these, and even with certain extinct animals.

In works of comparative anatomy, professors show that the
internal structures of mammals—bone for bone, muscle for muscle
—are identical. Then whence comes all this difference of ex-
ternal surface? How comes it that the Leopard is rosetted, the
Cheetah spotted, the Tiger and Zebra striped in one direction,
while the Ocelot is striped in another direction, and so forth?
Evolutionists declare that these external colours and markings
have been brought about by adaptation to surroundings. In the
following pages I have discussed what modification of this theory
is, in my judgment, needed in order to make it conformable to all
the facts that I shall place before the reader.

When we first begin to study the spotting and striping of
animals, they seem a chaos of markings, unregulated by any laws ;
but by degrees we become aware that there is some method in the
whole phenomenon, and the markings of one animal can be seen
to be derived from those of another, just as in the skeleton we see’
each bone to be derived from that of an ancestor. If not all, most
of the spotted and striped mammals, more especially the carnivora,
are reducible more or less to one plan of origin.
XXX STUDIES IN THE EVOLUTION OF ANIMALS

The bibliography of spots and stripes is not very abundant,
and biologists may perhaps have depended a little too much on
natural selection, as being sufficient to explain the creation of
everything.

‘The scope of some of the following studies is to show that the
spotting and striping of mammals, in their origin, are not purely
the results of natural selection from beginning to end. I believe
them to have been originally zzherited features, coming from very
remote ancestors, and altered in many ways by transmission from
species to species, from genus to genus.

So many persons are interested in Horses that to understand
in some way the origin of their curious markings would add to the
interest of these animals. Similarly it would add to the interest we
take in our domestic animals, if we could satisfactorily account for
the spotting and striping of our Cats and Dogs, and other mammals.
Our surroundings would again become peopled with the remote and
extinct ancestors from which those we now see have descended.

The evolutionist with his ‘eyes open, can find interest in
Leopard skins, in the dapples of Horses, and in the markings
of other animals; in the coloration of the legs of Horses, Dogs,
Cats, and in a hundred other things which the non-evolutionist
would pass by as ordinary insignificant phenomena, and _ totally
void of interest. Fifty lives would not suffice for the evolutionist
to exhaust the interest of things he may see around him. It is all
a study of the real method of creation.

It is usual for people to think of the Horse as an animal fit for
draught, for riding, hunting, racing, etc., but the evolutionist sees
both in his internal structure and in his external coloration, relation-
ships to animals which ordinary people think have nothing to do
with the Horse.

We shall see that rosetted animals must have been Jegions
INTRODUCTION XXXi

in past ages, and of all kinds and descriptions. The coloration of
the skin is not a thing that can be fossilised, and so one has to put
‘two and two together’ in order to discover an explanation for the
varied markings of the mammals of our day. We not infrequently
pass over the seemzng, and go a-hunting after the obscure and the
unlikely.

It seems to me that the organs of animals which receive and store
up impressions, which we call nerve-centres, are as much engaged
in influencing the form and coloration of the markings of the skin
as they are in moulding and modifying the skeleton and other
parts of the body. They are the controllers and regulators of the
whole life, not only of the individual but also of the race. And
the individuals forming a race were after all part and parcel of the
ancestral stock, and were at one time or other organically con-
nected with it.

I do not, however, pretend in these pages to account for every
speck and coloured hair, but to give my view of what seems to have
been the genesis of spots and stripes in mammals, and of the
contrasted coloration we see in so many animals, which would
indicate some sort of dla of coloration. I do not enter into
the microscopy of the subject—into how pigment cells behave
in fishes, and other small animals which change their coloration
and spotting according to surroundings.) We know that the
Leopard, the Tiger, the Zebra, and others do not do so, and there-
fore we have to account for the genesis of their more or less
permanent spots or stripes. My suggestion would appear to be a
‘vera causa’ of the markings of the Jaguar, the markings of all
other mammals, in cases where these exist, being only a modifica-
tion of such rosettes as those of the Jaguar, and z¢s markings only
a modification of vastly more ancient conditions.

One of the problems to be solved is—-How came the rosettes on.
XXXii STUDIES IN THE EVOLUTION OF ANIMALS

the Jaguar, the stripes on the Tiger and Zebra, the dapples on the
Horse into being? Undoubtedly they must have some reference
to ancestral features. What ancestor or ancestors have these
existing features been inherited from, for assuredly they present
evidence of inheritance as much as the bones of their skeletons ?

We should make a distinction between the general coloration
of an animal and its spot or stripe colouring ; both are liable to
vary zxdependently. The Cheetah, the Dalmatian Dog, and certain
Horses and other animals are black-spotted ; while certain Deer,
Phalangers, and certain Horses are white spotted.

Fossils certainly give us the structure of extinct animals, but I
hope to show that they can also tell us something, if not so
certainly, about the probable origin of certain markings we see on
existing animals. But in order to see all this a good deal of the
imaginative faculty will have to be brought into play.

Probably zoologists may look upon the markings of animals as
trivial and unimportant features, yet it would seem that markings,
if not the general coloration, are important zoological features, and
may tell a tale as interesting as that told by the teeth. Of course
skin coloration and markings are more liable to change, because
they have to adapt themselves perhaps more intimately to the
surroundings in which the animals happen to move.

Great importance among zoologists seems to be placed on the
character of the teeth of animals in grouping them for the purposes
of classification, as if these were absolutely the oz/y characters that
are inherited,

The reason why so much importance has been given to teeth
as a character indicating descent is that fossil vertebrates have
rarely anything but their simple skeleton to show what they may
have been like, and certainly the teeth may indicate their habits.
The skin characters have usually wholly disappeared, and we have
INTRODUCTION XXxiil

nothing to guide us, in that direction, but the skins of existing
animals,

There is, however, some evidence which would tend to make us
suspect that teeth may be liable to sudden changes, owing to con-
traction of the jaws. Teeth, like other bones, it would appear, are
subject to fusion or to dissociation, as the case may be. And the
writer on Seals in the Royal Natural History quotes an interesting
example of dissociation in teeth, which I have quoted more fully
in another place, as I think it very instructive, and the inference to
to be drawn from it important.

The doctrine of evolution has replaced every other doctrine of
creation, owing to the undeniable support that existing facts give
it. This being unstintedly admitted by all modern scientists, and
by many modern theologians also, there remains only to account,
in some way, for the appearance on this earth of the innumerable
creatures we see, including man himself, by the method of
evolution.

Lower down in the scale of life, beyond a certain stage, we
cannot go, in this investigation, because breaks occur which are at
present in no way filled up. Whether the gaps may or may not
be filled up at some future period no one living can say.

The evolution of the structure of one kind of animal from
another has been made clear enough, but the evolution of the
coloration of one kind of animal from another has not been made
sufficiently clear. Probably this feature in evolution has been
neglected, because it offered difficulties which perhaps looked like
puzzles. It is this feature of evolution which I have tried to make
clear in some of the following pages. With regard to drawing
conclusions, Professor Huxley! remarks :—

‘What in fact lay at the foundation of all Zadig’s arguments

1*On the method of Zadig,’ Sczence and Hebrew Tradition, pp. 7 and 8.
¢
XXXIV STUDIES IN THE EVOLUTION OF ANIMALS

but the coarse commonplace assumption, upon which every act of
our daily lives is based, that we may conclude from an effect
to the pre-existence of a cause competent to produce that effect.

‘Zadig was able to do this because he perceived endless minute
differences (and likenesses) where untrained eyes discern nothing ;
and because the unconscious logic of common sense compelled him
to account for these effects by the causes he knew to be competent
to produce them.’
SPOTTED AND STRIPED MAMMALS

(HORSES EXCEPTED)
“Yer, if he would be guided by the true spirit of scientific inquiry, he must maintain an
unsettled opinion as long as the evidence is incomplete or contradictory ; he must adopt
conclusions only where the evidence is complete and convincing ; he must ever hold his
mind open to new evidence, even if it bring about the abandonment of accepted beliefs.
He may, if desirable, quote the conclusions of others, and, if well read, he may thus
become widely informed; but he will fail to gain the best benefit that comes from
careful study, if he does not reach opinions and conclusions for himself, forming them
only as fast as the evidence that may support them is clearly understood.’
Elementary Meteorology, by Prof. W. M. Davis.
PART I

SPOTTED AND STRIPED MAMMALS

(HORSES EXCEPTED)

A GLANCE at the living Mammals in the gardens of the Zoological
Society, and at the mounted specimens in the Natural History
Museum, will show us what a large number of Mammals of
several orders and of many genera are either spotted or striped,
or both spotted and striped. There is a large number of Mammals
which may be said to have permanently lost their spots or stripes ;
but there are not very many which, either in the childhood of
the individual or in some of its species, either on the legs, on
the tail, or on other parts, do not betray their descent by vestiges
of either spots or stripes.

In the Appendices I have given lists of various Mammals
which show spotting or striping now, or show vestiges of descent
from spotted and striped ancestors. Some of them have a plain
body and spotted or striped legs; while others have only a
ringed tail to show what they came from. These tail rings,
even when they are the sole markings, are in my opinion dis-
tinct vestiges of either a spotted or striped ancestry.

If one had a fuller acquaintance with the childhood and
adulthood of all Mammals, under different conditions of climate
and other surroundings, the probability is that these lists might
be much lengthened, and we might perhaps then come to the
4 STUDIES IN THE EVOLUTION OF ANIMALS

conclusion that most Mammals, at least, had a spotted ancestry

more or less remote, not even excluding the Marsupials of
Australia.

The earliest record that I have met with of a striped Mammal

is that shown in Fig. 1. It is the bone handle of a poignard

i of a prehistoric period. It

\( Hippos, represents some kind of deer

Se ee which had partial broad stripes

oe on its flanks, evidently ves-

tiges of something like the

Fic. 1.—Cast of a handle of poignard found at 3
Bruniquel, on the river Aseyran, France. (Brit. zebra bands in the same

Mus.: Mammoth and Reindeer period.) regions.

It might perhaps be thought, as an alternative, that these
marks were not intended by the carver to indicate skin-stripes,
but merely the projections of the ribs.

If, however, we consider that, if the prehistoric savage knew
anything, he must have known a great deal about the ribs of the
animals he was continually hunting, cutting up, and feeding upon,
we shall see that he must have known that the ribs of the deer
did not extend to its haunches, Therefore, the transverse stripings
on this ancient model of a deer can hardly be taken to have
been meant to indicate the projections of the ribs, but are more
likely to have been meant for skin-stripes. Moreover, if the
reader will turn to Appendix A, Fig. 22, he will see an
antelope with striping not very unlike that of this prehistoric
relic,

I shall, however, leave this point to be decided by archeologists
and paleontologists, and proceed with my story.

What causes the changes in the markings of different animals,
and at different ages, I do not know. Presumably atomic changes
in the nerve centres, initiated by surroundings, heredity, or what
SPOTTED AND STRIPED MAMMALS 5

not, become reflected electrically on the skin, whether during
the embryonic stage or afterwards, and cause aggregation or
dissociation or other changes in pigment cells.

Evolutionary biologists—and probably there are at present
few or no biologists who have zof accepted the doctrine of
Evolution—seem inclined to consider that these markings in
animals are the result of natural selection, acting cumulatively
on some fortuitous variations that may have occurred, and do
occur, in an infinity of ways. By natural selection is meant
the weeding-out, generation after generation, of all those varia-
tions which are insufficiently protected by their surroundings
for either offence or defence, or both, and by keeping alive those
which are most fit. Reproduction and heredity then maintain
and improve this selection.

Dr. Alfred Russel Wallace says! that ‘Professor William
H. Bremer of Yale College has shown that the white marks or
the spots of domesticated animals are rarely symmetrical, but
have a tendency to appear more frequently on the left side.
This is the case with Horses, Cattle, Dogs, and Swine... .
Among wild animals, the Skunk varies considerably in the
amount of white on the body; and this, too, was found to
be usually greatest on the left side? A close examination of
numerous striped or spotted species, as Tigers, Jaguars, Zebras,
etc., showed that the bilateral symmetry was not exact, although
the general effect of the two sides was the same. This is pre-
cisely what we should expect if the symmetry is not the result
of a general law of the organism, but has been, in part at least,
produced and preserved for the useful purpose of recognition by

1 Note to p. 217, Darwinism.
2 I should say this is a sure indication that the difference does not depend on the

shin, but on the znegual action of the two halves of the nerve centre.
6 STUDIES IN THE EVOLUTION OF ANIMALS

the animal’s fellows of the same species, and especially by the
sexes and the young.’!

Then on p. 199, quoting from Major Walford, a Tiger-hunter,
Dr. Wallace says: ‘There can be no doubt whatever that the
colour of both the Tiger and the Panther renders them almost
invisible, especially in a strong blaze of light, when among grass ;
and one does not seem to notice stripes or spots till they are
dead.’

I suspect the ‘strong blaze of light’ had something to do
with the invisibility on the part of Major Walford, for he says
that natives could see the Tiger, which. would seem to mean that
their eyes are accustomed to strong light, and can adapt them-
selves to it.

There cannot, however, be any doubt that the two sides of a
spotted or striped animal are unsymmetrical. A glance at the
Tiger and Leopard skins in the London fur-shops would be
enough to convince any one of this. And it is, I think, due to
a want of zdentical nervous action in doth halves of the central
nerve organ, to the atomic action of which I would attribute
all skin colorations.

One of the objects of these pages is to investigate how far the
markings of animals are due to natural selection, and how far they
are not.

The innumerable variations in the markings of horses, which we
see in the streets of London, will be made to contribute evidence
in this interesting investigation.

In many cases it will not be difficult to show that the striped
animal is only a modification of the spotted animal.

1 The probability is that wild animals recognise their fellows more by scent than by
sight : nevertheless, it is curious to note how dogs recognise dogs of any breed, at a
distance ; they, however, complete their investigation by means of the nose.
SPOTTED AND STRIPED MAMMALS 7

We shall first examine some of the most markedly spotted and
best-known animals, viz., the Jaguar, the Leopard, the Cheetah, the
Ocelot, and the Serval. For my purpose the Jaguar and Leopard,
and also the Panther, may be considered as ove animal, the others
being differently marked.

Mr. G. P. Sanderson! says: ‘The distinction between the
Panther and Leopard is practically small, and lies chiefly in the
inferior size of the Leopard. The markings, habits, and general
appearance (except size) of the two animals are almost identical.
But neither can be confounded with the Cheetah, even by the most
casual observer ... the spots of the Panther and Leopard are
grouped in rosettes, enclosing a portion of the ground colour ;?
whereas those of the Cheetah are solid, and are separate from
each other.’

Mr. Blandford? declares that there is no difference whatever
between the Panther and Leopard, and Mr. Blyth was of the same
opinion. He also states that black and ordinary Leopard cubs
are often found in the same litter, and that an albino Leopard is
figured in Buchanan Hamilton’s drawings.

Mr. Sanderson further states that the black Leopards from Java
have all sorts of shades, from jet-black to light brown; and that
the black Leopard seems to be confined, at least in India, to heavy
forest tracts, while the common variety in Mysore frequents open
country, and also rocky localities.

It should be here noted that in black Leopards, as in certain
black Cats, the markings are often plainly visible in certain
lights. The marking is persistent, and quite independent of
melanism, or that condition which produces the general blackness

of the skin.

1 ‘Wild Beasts of India, p. 327.
2 Sometimes of a different shade from the ground colour.
3 Mammals of India, p. 68.
8 STUDIES IN THE EVOLUTION OF ANIMALS

The Jaguar is only a South American Leopard, and black varia-
tions of it are frequent also there.

It may be interesting to note that the black Leopards of Africa
differ somewhat from the black Leopards of Asia.

The Royal Natural History, vol. i. p. 338, regarding the
black African Leopards, states that in 1885 a black specimen,
obtained near Grahamstown, was described by Dr. Giinther. Its
ground colour was a rich tawny, with an orange tinge; but
the spots, instead of being of the usual rosette-like form, were
nearly all small and solid, like those on the head of an ordinary
Leopard.

In the black Leopards of Asia the rosettes are retained, while in
those of Africa they appear to lose their ocellus and become solid.
The jet-black Leopards, like the jet-black domestic Cats, usually
lose all traces of markings.

Leopards and Jaguars are tree-loving animals, and therefore
it seems obvious to evolutionists that their markings were the
result of natural selection, acting cumulatively on favourable
variations so as ultimately to harmonise them with a surround-
ing of speckled lights and shades produced by the leaves of
trees.

Unlike the Lion and the Tiger, the Leopard of India is ‘thor-
oughly at home in trees, running up a straight-stemmed and smooth-
barked trunk with the speed and agility of a Monkey’; and Mr.
Hunter remarks that in Africa ‘the Leopard nearly always puts the
remains of his “kill” up a tree” 2 Then the Jaguar ‘is one of the
most expert climbers among the larger Cats’ ;* and during inun-
dations it is said that it will sometimes take to an arboreal life,
preying upon Monkeys.

So we see there is ample evidence to show that the Leopards

1 Roy. Nat. Hist., vol. i. p. 390. * Lbid. p. 392. 3 /bid. p. 395.
Pp P- 395
SPOTTED AND STRIPED MAMMALS 9

have their markings in harmony with the surroundings of an
arboreal life.

 

 

 

 

 

FG. 2.—Jaguar, from a photograph by Gambier Bolton, F.Z.S.

 

 

Fic. 3.—Leopard, from a photograph by Gambier Bolton, F.Z.S.

#

A glance ‘at the markings of the Jaguar and Leopard in Figs,
2 and 3 will show that a large number of their rosettes is made
up of groups of small spots, each group forming an isolated and
10 STUDIES IN THE EVOLUTION OF ANIMALS

irregular ring of small black spots with an enclosed space. This
space may be either of the same colour as the general ground of
the skin, or of a darker shade, and sometimes of a different hue.
Moreover, on the Jaguar skin (Fig. 4) there are many rosettes which
have one or more small black specks in the #zzddle of the enclosed
space, which in Leopards proper seem to be obliterated, owing
perhaps to a contraction of the entire rosette.

In the Tring Museum there is a fine specimen of a Jaguar. On
its flank are very large polygonal rosettes, with from one to sex
specks in the enclosed space.

If any one will take the trouble to look over the Leopard skins
in the windows of the London furriers, he will be at once convinced
that the rosettes even in the same skin vary immensely ;! and if
different skins are compared it will be found that, although the
general mapping may be similar, the detail shows that there are
scarcely two skins alike. Indeed, the skins are as different as the
faces one sees among the people in the crowded streets of London.
It seems astonishing that, among the thousands of faces one sees,
there should not be two alike. It is the same with the coloration
of most animals.

Then, if we examine the skins of Mammals which are sup-
posed to be of different species, although of the same genus, we
find astonishing modifications of what I consider the typical
rosettes of the Jaguar.

A very interesting monograph of the Felide by D. G. Elliot
shows, by means of the beautifully coloured plates, not only the
modifications of rosettes, but all manner of intermediate stages
up to total obliteration of all markings. The transitions from
rosettes to spots and stripes can there be readily seen.

1 A variety of Jaguar from Mexico is characterised by the distance at which the small
spots which ordinarily constitute the rings are placed from one another, so that comrlete
rings or rosettes of spots only occasionally occur. Roy. Mat. Hist., vol. i. p. 395.
SPOTTED AND STRIPED MAMMALS 11

I can only give a small number of Cats in this superb mono-
graph, to show the principal variations from the typical rosettes
of the Jaguar. .

In Elliot’s Jaguar (Fed?s onca), which presumably was copied
from nature, there are on the flanks very distinct rosettes, made
up of polygonal rings of black spots, more or less fused, and
enclosing a space which is differently coloured from the inter-
rosette ground ; and each rosette has a distinct black speck in the
centre of the enclosed space.

Then his Margay (F. tigrina) is of a Leopard-yellow colour,
rosetted in various ways, the rosettes being made up of three, four,
and five black spots, which enclose a brown space. It is, more:
over, distinctly barred on the shoulder and back. (See another
variant on p. 418 of Roy. Nat. Hist, vol. i.)

Fontanier’s Spotted Cat (/% ¢ristzs) is something like a Jaguar,
but its rosettes are distorted in various ways.

From this we pass to his African Golden Cat (/. chrysostrix),
which is either grey or brown trimmed with Leopard-yellow. Its
spots are solid.

The Serval (F. serval) is much the same ; only, in addition, it
has fusions of spots into longitudinal streaks.1

The Rubiginous Cat (/. rudiginosa) is of a brownish-grey,
with solid black spots arranged in longitudinal rows, preparatory
to fusing in longitudinal stripes, like those on the back of the neck.

We come then to the Pampas Cat (F. payeros), It has brown
longitudinal bands on grey ground, in the manner of the Ocelots,
and the legs are transversely banded. (See variant of this on
p. 431, Roy. Nat. Hist.)

The Clouded Tiger is very interesting (/ dard), It has a

1 The Serval is also subject to melanoid variations, and the spots are distinctly visible
when viewed in certain lights. (oy. Mat. Hist., vol. i. p. 414.)
12 STUDIES IN THE EVOLUTION OF ANIMALS

yellowish-brown general colour, with broad transverse patches of
a yellowish-grey, margined with black blotchés or spots. The
patches are evidently fusions of several rosettes of a similar colour.
The haunches are rosetted, and the tail has its rings double, which
is also a vestige of a rosetted body.

There is another much like the foregoing, the little Marbled
Tiger (4. marmorata)4 It is either Leopard-yellow or grey, with
large clouded patches edged and spotted with black, while the
general colour is paler. Its haunches and shoulders are spotted.
The tail is either spotted or ringed.

We come now to the Caffer Cat (& caffra), which is of a
bluish-grey, striped with black, Tiger-fashion. (See variant on
p. 421, Roy. Nat. Hist.)

From this we pass to the Tigers, which every one knows.

We pass, then, to total obliteration of spots and stripes in
the self-coloured Cats, like the Puma (F. concolor), which is also
called Cougar, Panther, and American Lion. In the adult
stage it is all plain, and of a rich brownish-grey, but its kittens
are spotted.

How astonished the Puma must be when she has cubs for the
first time! She looks at her husband’s coat and at her own, and
sees them of a uniform rich isabelline colour, and then she finds
her kittens are born spotted all over like young leopards. Are
these really my children? Yes, your very own! You have
succeeded in shaking off your rosettes, but your kittens still
masquerade in that antiquated dress, and prove to you that after
all your pedigree is identical with that of the Leopard !

There are innumerable transition markings between rosettes,
solid spots, and stripes, and many Cats have only vestiges of spots
or stripes. The tails of most of these elzde are ringed, and the

1 In the Roy. Nat. Hist. these are called Clouded Zeogard and Marbled Cat.
SPOTTED AND STRIPED MAMMALS 13

under surfaces of most of them are paver than the back and flanks,
and in some cases wholly zwézte.

Elliot’s monograph of the Fe/de contains gradations, modifi-
cations, and transformations of rosettes and spots, which can be
studied with comfort within the compass of a book. It is like a
museum of Cats.

To facilitate the examination and comparison of Leopard and
Jaguar rosettes, and to show both flanks at one glance, I have
given in Figs. 4-7 some skins spread out; and Fig. 59 gives a
number of variations of single rosettes taken from numerous
Leopard skins.

It will be seen that on the Jaguar skin there is a large number
of rosettes consisting of an irregular or polygonal ring of small
spots enclosing a space, in the middle of which, as I said, there are
one or more specks. At times the ring-spots are dissociated, as on
the shoulder, and they appear like an irregular group; at other
times the ring-spots coalesce wholly or partially, and form a more
or less continuous polygonal ring, as in those of Fig. 7, with or
without the central specks. The rosettes of what are commonly
called Leopards are usually wéthout the enclosed specks.

This continuous ring can best be seen on the Leopard skin of
Fig. 7, already alluded to.

Again, we see that on the abdominal surface the rosettes tend
to coalesce further, with obliteration of the enclosed space, and, in
the Jaguar, to form a sort of trefoil, quadrifoil, pentafoil, etc.

I would here note that on the tails of these Leopards the
rosettes, at first isolated, tend to coalesce and form transverse rings
towards the tips, with obliteration of the enclosed space ; and that
along the spine the rosettes tend to coalesce longitudinally, and to
form a continuous dorsal line or band.

All variations of Leopard rosettes would seem to be modifica-
 

 

Fic. 4.— Skin of Jaguar, fronia Photograph by Messrs. Dixon and Son,

Skin lent by Messrs. Jeffs and Harris.
 

Fic. 5.—Skin of Leopard—may be African; from a Photograph by Messrs. Dixon and Son.
Skin lent by Messrs. Jeffs and Harris,
 

Fic. 6.—Skin of Leopard—probably Chinese ; from a Photograph by Messrs. Dixon and Son,
Skin lent by Messrs. Jeffs and Harris.
pcan

Doweay wk

 

Fic. 7.—Skin of Chinese Leopard, from a photograph by Messrs. Dixon and Son.
Skin lent by Messrs. Back and Co.

B
18 STUDIES IN THE EVOLUTION OF ANIMALS

tions of those on the fanz of the Jaguar; and Fig. 4 shows many
intermediate forms between the Jaguar rosettes enclosing specks

and the solid rosettes or spots of the abdominal region.
In one particular Leopard skin! I noticed a very curious varia-
tion, shown in Fig. 8. It appeared

i. 3 oe as if the enclosed specks had been

J a @ a *  ¢xtruded from the rosette ring.

(\ ae oy In some regions it is not always
O

easy to make out whether the

Fic, 8,—Occasional variants of Jaguar rosettes are a coalescence or a dis-

and Leopard rosettes. eine 2
sociation of spots.

Fig. 9 shows rosettes from the scapular regions of a Jaguar

skin. Some look like a consolidation and others like a dissocia-

Be

eee ;
Clee i WE
Co: Gee OS
7 < « o OD 4
oe oR

Fic. 9.—Various forms of rosettes from the scapular regions of a Jaguar skin.

tion of spots. The groups shown in Fig. 59 (Nos. 30-32) are
obviously a dissociation of the ring-spots.

The Jaguar in the Science and Art Museum, Edinburgh, has
the spaces enclosed by the rosettes of the whole skin of a deeper
shade of fawn than the general ground colour ; and on the hind-legs

1 Shown to me at Messrs. Back and Co.’s,

2 Two Leopards, described by M. A. Milne Edwards, ‘ were remarkable for the
circumstance that the markings on the flanks were more like rings than rosettes’ (p. 390,
Roy. Nat. Hist, vol. i.)
SPOTTED AND STRIPED MAMMALS 19

it has fusions of the ring-spots into bigger spots or blotches, with
a deeper shade of fawn colour between them than the general fawn
colour. I have endeavoured to show this in No. 9, Fig. 59.

Moreover, some Leopards, such as that of Fig. 6, have large
solid rosettes of irregular shape on their haunches, while those on
their flanks are ocellated.

This, I think, is clear evidence that, in these cases at least, the
haunch rosettes are mere contractions of the larger typical rosettes
on the flanks.

A glance at the Jaguar skin of Fig. 2 also shows distinctly that
the exclosed spaces of the rosettes are of a deeper shade than the
general colour defween the rosettes. I mention these details
because in these Mammals there appear to be three distinct
colorations, viz., the colour of the inter-rosette spaces, of the rings,
and of the enclosed space. All three may vary zxdependently of
the others, not only in colour, but also in form.

The different colours of the inter-rosette spaces, of the spots,
and of the enclosed spaces, would seem to indicate that each has
a separate’ and distinct nerve-centre, as much Jocalised as the
centres of the different parts of the arm, the leg, the face, etc.,
and that each of these components of the whole surface may vary
independently of the others. It seems curious that the spots of
the Dalmatian Dog should be black on a white ground, and those
of the Phalanger and Dasyure white on a black ground.

The general coloration of Mammals seems of little importance,
as it varies in almost every individual; what is tan in one may
be either black or white in another. But the ‘markings’ and
the colorations, which are seen to be like a sort of ‘ plan, are of
much greater importance, as they more or less indicate, I think,
something inherited from very vemote ancestors.

Let us now take a look at a very differently spotted Mammal.
20 STUDIES IN THE EVOLUTION OF ANIMALS

Fig. 10 shows the picture of a living Cheetah, and Fig. 11 the
skin of a similar animal (perhaps an older one) spread out to see
both sides at once.. In the Cheetah we find numerous solid circular
spots, with minute specks interspersed among them. The large
spots are disposed in transverse rows on the flanks (Fig. 10).
The minute specks, however, in the figure of the skin are inter-
spersed among the larger spots, apparently without any order ;

 

 

 

 

 

Fic. 10,—Picture of a living Cheetah, from a photograph by Ottomar Anechiitz,
Lissa (Posen).

while in the figure of the living animal the minuter specks appear
to be disposed in many places in rows also, alternating with the
rows of the bigger spots.

In the Cheetah it is not easy to make out whether the larger
spots are consolidations of the extre Leopard rosettes, or dissocia-
tions of the spots forming the rosette rings of the Jaguar. The

1 At the International Fur Stores, Regent Street, I was shown a Cheetah skin with
some of the rows on the flank undergoing fusion, and forming beaded strings ; and
several couples of spots were actually fused into one blotch.
 

Fic. 11.—Skin of a Cheetah—perhaps of an old one; from a photograph by Messrs. Dixon
and Son. Skin lent by Messrs. Back and Co.
22 STUDIES IN THE EVOLUTION OF ANIMALS

spots on the Jaguar’s shoulder (Fig. 4) are evidently dzssociated
rosettes, while the spots on its hind-quarters and abdomen are
evidently fusions or consolidations of rosettes ; so that the Cheetah
spotting may have had either the one or the other origin.’

Anyhow, it is evident that the transverse strings of spots on
the fore-legs of the Cheetah (Fig. 10) are homologous with similar
transverse marks on the fore-legs of the Jaguar and other Leopards.

As to the minute specks, I have a suspicion that they may
have possibly resulted from the specks enclosed within the Jaguar
rosettes. In the modifications which these animals have under-
gone, the specks may have been extruded, as we have almost
seen them do in Fig. 8, and have become disseminated among the
bigger spots.

A close scrutiny of the Cheetah spots may lead one to detect
something like dissociated rosettes, especially on the right shoulder
and haunches of the skin figure ; but on the haunches and tail of
the living-animal figure the spots look more like consolidations of
whole rosettes.

There is no good reason why the characteristic spotting of the
Cheetah should not be a combination of both processes, viz., dis-
sociation in some parts and consolidation in others; for in the
same animal—the Jaguar—we find typical rosettes on the flanks,
dissociated rosettes on the shoulders, and consolidated rosettes on
the abdomen and legs. In certain Leopards the enclosed specks
become entirely obliterated, while in the Cheetah these little specks
may form one of its characteristic features.

Fig. 59 (No. 35) shows four groups from the flank of a Cheetah ;
and on the haunch of a Cheetah in the Natural History Museum,

1 Of two Cheetahs in the Tring Museum, one has isolated spots on half its tail,

while the other has, in the same part, 7zgs wilh scolloped edges, indicating a fusion of
spots.
SPOTTED AND STRIPED MAMMALS 23

as shown in Fig. 12, there is a similar disposition of large round
spots and minute specks, From this one might perhaps surmise
that the circular spots in the Cheetah

represent the modified enclosed space of the .
Jaguar rosettes, while the specks represent @ 26
the dissociated ring of spotlets. The Oe : @

change of colour of the enclosed space from ae :
brown to black is not wholly imaginary, Fic. 12.—Group of Spots
for in horses we find that the white spots Tae He Mae. aces
of dappled animals are changed to black

spots in the roan and to brown spots in the strawberry roan.?
I confess, however, that the Cheetah spotting is rather puzzling,
for the individual spots are as round as a shilling, with a general
equality of size,and they do not give any indication of a coalescence
of minor spots like those on the abdomen of the Jaguar. Yet the
consolidated rosettes on the paws of the latter animal are not
unlike those of the Cheetah. They have, moreover, minute specks
among them. As spots can be wholly obliterated, so, I suppose,
they can diminish in size.

In a Leopard skin there were here and there minute specks, like
those of the Cheetah, interspersed among the usual rosettes. This
is uncommon in Leopard skins ; but in the Natural History Museum
(case 12) a Leopard among the consolidated rosettes of its fore-legs
has a number of minute specks like those of the Cheetah ; and in
the window of the International Fur Stores I saw a Leopard skin
which had small and roundish spots on the back (shoulder region)
which were not unlike the larger spots of the Cheetah. So that it
is not improbable that the larger circular spots of the Cheetah may

'@

«

1 We may have melanism or albinism or shades thereof on the evtdre surface, or
changes of colour in certaix parts only, as I shall endeavour to show in another place.
In another place I have also indicated that black, tan, and white are interchangeable
colours.
24 STUDIES IN THE EVOLUTION OF ANIMALS

be, after all, consolidated Leopard rosettes further modified into
circular spots.

On the other hand, Fig. 12 shows conditions which would
suggest that it is the evclosed spaces of the Jaguar rosettes which
become the large round spots of the Cheetah, while the specks are
the dissociated rings of spotlets ; only the enclosed space in this case
would be, as I said, changed from irregular brown to circular black.

A very young Cheetah in the Natural History Museum (case 16
—Gueparda jubata), from the Cape of Good Hope, shows a very
interesting variation. It is brown with faint spots, but what is

still more curious is the fact that its

o. gon ; : '
Fy oae ko back is grey like that of a badger !
o
oF Peta Lae It may be of some interest to show
Oo
Bes eI SS how much variation the Jaguar rosettes

Fic. 13.—Rosettes from a can undergo. Fig. 13 is taken from
tue Griffith's a Jaguar pictured in Griffith’s Cuvier.
They may, perhaps, be closely matched

from groups on the Cheetah skin of Fig. 11.

This much is clear to me, that the Cheetah and the Leopard
are closely allied in habits and structure, and their spotting, how-
ever modified it may have become, must have had oxe ancestral
origin, not necessarily of course from the same ixdividual, but
from the same sfecies of ancestor; and that the difference in the
existing animals comes from microscopical changes in the nerve-
centres, which would result in pronounced differences on the sézn.

The student of animal markings would do well to study, as
a previous training, the many-synonymed orchid—Odon/éoglossuim
crispum, and others of the same genus. Nothing is more interest-
ing than a review of the variations of blotches on the petals of this
genus. There are blotches of various sizes and forms; there are
cross-bars ; in some varieties there are simg/e little spots on each
SPOTTED AND STRIPED MAMMALS 25

petal ; and, finally, in others every trace of blotching or spotting
disappears, and the whole flower is white, with a little lemon-colour
on the lip. In the Déctionary of Gardening it is stated that ‘it
is a plant which varies to an almost endless extent, no two of the
many thousands imported being perhaps exactly alike.’

 

Fic, 14.—(a) Young and (4) Adult of Spotted Deer (47s maculatus, Nat. Hist. Mus.).

Not impossibly, also, the stretching of the skin as the animal
grows may, in some instances, tend to modify the grouping of the
spots, and have something to do with dissociation. On the other
hand, contraction of the skin in other regions may have something
to do with consolidation of rosettes.

Perhaps, in illustration of the former conditions, one might take
the case of the Spotted Deer shown in outline in Fig. 14. The
26 STUDIES IN THE EVOLUTION OF ANIMALS

young one (a) has its white spots close to each other, in some parts
almost coalescing into blotches. Then as the animal grows the
spots become more distinct, and in the adult they are separated by
long intervals, as shown in (0).

However this may be, we cannot ignore the fact that the whole
physiology of the skin in Mammals, with its colourings and mark-
ings, is under the control of the nerve-centres (perhaps as much as
electro-plating is under the control of the battery or dynamo), and
these again are under the various influences of heredity, age, varia-
tions of temperature, climate, composition of the blood, and other
surroundings, of which we know yet too little.?

In the various kinds of Leopards we see that not only the
rosettes differ, but also the spaces between them differ much.

These inter-rosette spaces run into each other, and form a
sort of broad reticulation which is the ground-colouring of the
skin.

The Leopard of Kismaya, British East Africa,? has its rosettes
much closer than those of the Indian Leopard or of the American
Jaguar, so that it seems much darker than they. The comparative
smallness of this animal, supposing the number of rosettes to be
equal, may, I think, sometimes account for the compactness of the
rosettes, as well as for their elementary spotlets.

At Mr. Rowland Ward’s establishment, Piccadilly, I was shown
a very small fcetal Leopard, that is, in a stage defore birth. It was
closely spotted all over, but none of the spots were ocellated.
Another young Leopard, but older than the preceding, had a com-
mencing faint ocellus in some of its spots. On the other hand, a very

1 Orchids seem to undergo similar alteration in the spotting of their flowers, without
any nervous influence that can be detected. Yet there must be some means of com-
munication in the Dvomea between the bristles and the hinges of the leaf-blades,
analogous to nervous or electric communication.

? In the Zoological Society’s Gardens.
SPOTTED AND STRIPED MAMMALS 27

young animal in the Natural History Museum (case 13), ticketed
as a young Jaguar, has xo sfots at all, but is of a uniform brown.
The variations in the disposition of the rosettes of Leopards are

very considerable. In
some specimens they
are distributed irregu-
larly, in others they
occur in slanting rows,
asin Fig. 15 (a). Where
they are crowded, two
or more fuse into an
elongated ocellus, as
in (6). The Fig. 59
shows how numerous
are the variations in
individual rosettes.
We should make a
distinction between the
general colour and the
spot or rosette colour ;
both, as I said, are
liable to vary znde-
pendently. The Cheetah
and the Dalmatian
Dog are black-spotted,
while the Deer is white-

 

Fic. 15—(Diagrammatic disposition of leopard mark-
ings, both taken roughly from skins in furriers’ windows.
(a) Rows of rosettes, which might fuse into stripes.
(4) Fusion of two or more rosettes.

spotted. The ordinary Leopard has a general tan colour, the
melanoid a general brown colour, and the Snow-leopard! a general
white colour, although the rosettes remain black in all cases.

1 Of two Snow-leopards in the Tring Museum, one has ocellated rosettes, and the
other has a large number of the rosettes so/éd, especially on the shoulders, haunches,

and lower part of flanks.
28 STUDIES IN THE EVOLUTION OF ANIMALS

In these variations we again find a parallel in Odontoglossum.
Some species are pure wzte, with maroon blotches, or spots, or
bars, while others are ye//ow, with maroon blotching.

The spots on the legs and tail of the Lion of Fig. 16 (a) leave
no doubt that the ancestors of the Lion and Leopard were one. In
adult Lions the rosettes become more and more obliterated, but in
the young they cannot be mistaken for other than Leopard-spotting.
The same may be said of the spots on the fore-leg of the Puma
shown in Fig. 16 (4). In the Science and Art Museum of Edin-
burgh there is a largish Cat, ticketed Puma, which may be a
young one. It is of a light reddish-fawn colour,’ with distinct spots
all over it of a deeper fawn. Its present general colour is not
unlike that of the red domestic Cat.

The Encyclopedia Bretannica says: ‘The young of the Puma, as in
the case with the other plain-coloured Heide, are, when born, spotted
with dusky brown, and the tail ringed. These markings gradually
fade, and quite disappear before the animal becomes full-grown,’

Some varieties of Lynx, although their backs are plain, have
spots on their abdomen and legs. These may be seen in the Natural
History Museum.

Then there is a large number of widely different animals, such
as Racoons, Lemurs, and many others,? which, although they have
neither spots nor stripes on their bodies and legs, yet have distinct
rings on their tails, like those of the Leopards and Tigers of our
illustrations. Therefore, all these ring-tailed animals should, I
think, be credited with either a spotted or a striped ancestry.

In the Appendix I have given a list of animals, of very varied
natures, which have ring-tails. They probably a// descended from
spotted ancestors, and the marks on their tails are the only vestige
which now indicates the history of their ancestry.

1 Skins become faded in time. 2 See Appendix E.
 

—(a) Lion, and (4) Puma, from photographs by Ottomar Anechiitz.

FIG, 16.
30 STUDIES IN THE EVOLUTION OF ANIMALS

As to the markings of the Serval in Fig. 17, it is not likely that
any one will take them for any other than consolidated Leopard
rosettes placed widely apart, and in places arranged in longitudinal
series.t

 

 

Fic. 17.—-Serval, from a photograph by Ottomar Anechiitz.

In Fig. 18 is given a Marbled Cat, which, although ancestrally
rosetted, has its spotting undergoing obliteration, like the adult
Pumas and Lions.

We now turn to the numerous variations in the markings of
Ocelots.

1 Note the black mark from the heel to the toes of hind-legs. It is an interesting
feature, to which I shall refer in another place,
 

 

 

 

 

Fic. 18.—Marbled Cat : on the flank it has distinct rosettes, and on the legs transverse
stripes. From a photograph by Ottomar Anechiitz.
32 STUDIES IN THE EVOLUTION OF ANIMALS

Fig. 19 (a) shows one variety in which the typical Leopard
rosettes are plainly recognisable, only they are arranged in longi-

(2)

 

 

 

 

 

 

 

 

 

Fic. 19.—Two distinct variations of Ocelots, from photographs by Ottomar Anechiitz.

tudinal order, and on the flanks and shoulder the rosettes coalesce
into parallel bands, with the enclosed spaces also continuous. It
SPOTTED AND STRIPED MAMMALS 33

should be noted that on the shoulder of this Ocelot there is a
tendency to dissociation of the rosette-spots.

Then in Fig. 19 (6) we have an Ocelot in which the same
character is intensified and further modified, the enclosed spaces
being of a different colour from either the rings or the general
ground-colour.

In the Natural History Museum there are some Ocelots which
show a further coalescence of the rosettes into more perfect longi-

ie ee

   

Fic. 20.—Diagrammatic sketch showing transformation of Ocelot rosettes into longitudinal
bands :—
(2) Rosettes arranged in longitudinal rows.
(4) Their upper and lower segments fusing.
(c) The rows of rosettes completely fused into bands of a brownish colour, margined with
black.
(d) A row of rosettes from the flank of a Leopard skin ; these might readily fuse into ¢awiz
stripes, as seen in Fig. 24.
tudinal bands, in which the traces of the Leopard rosettes are
almost wholly obliterated ; and it would not be easy to conceive
how they originated, without knowledge of other varieties of
Ocelots which indicate the steps leading to the longitudinally
banded Ocelot.
In Fig. 20 I have endeavoured to give a rough sketch of the
passage from the Jaguar rosettes to the longitudinal parti-coloured

bands of certain Ocelots.
Cc
34 STUDIES IN THE EVOLUTION OF ANIMALS

The shading of a, 4, ¢ is intended to show the brownish
colour of the enclosed space, so different from the general ground-
colour.

In the same figure (d) I have given a row of rosettes taken
from the flank of a Leopard skin, disposed diagonally. Like the
Ocelot rosettes, they might readily coalesce into stripes. Indeed,
there are many Tiger skins (Fig. 24) which have their stripes in
pairs; and many brindled Dogs have similar markings. These
may have resulted from such a disposition of rosettes as that here
shown. I have seen several Leopard skins with their flank rosettes
disposed in slanting rows (Fig. 15, a).

To understand the transformation of the Ocelot rosettes, we
should bear in mind that the Jaguar rosettes are made up typically
of a polygonal ring of spots enclosing a space which is of a darker
colour than the zzter-rosette spaces, and that the enclosed space
contains some minute black specks. We find ‘all these elements
in the Ocelot markings, only they are differently arranged.!

Reference to the Ocelot figure on p. 417 of the Royal Nat. Hist.
will make the transformation of the Jaguar rosettes into Ocelot bands
quite clear. In this figure the lower row of flank marks is made up
of distznct rosettes composed of distinct spots, like those of some
variations of the Jaguar. The next row above it is largely made
up of fused rosettes, and the row above that again is one long band
of fused rosettes, the rings becoming the black border of the band,
and the central spots becoming a row of small spots in the middle
of the band. The rest of the body is covered with patches of
fused rosettes. The Ocelot is essentially a South American
species, and like its close relative, the Jaguar, is said to be an
expert climber.

From the markings of the ocelot the transition is easy to those

See Stuffed Animals, Natural History Museum—case containing Ocelots.
SPOTTED AND STRIPED MAMMALS 35

of the Marbled Cat (/. marmorata), and those of the Clouded
Leopard (/. nebulosa), both of which can be seen on pp. 409 and
407 of the Roy. Nat. Hist.

Besides the two variations of Ocelot which I have given, there
are others which have longitudinal stripes that do not enclose any
spaces, and are not unlike those on the shoulder of the light-
coloured Ocelot in the foregoing figure (19).

There is a large number of spotted animals, and in the Appen-
dix I have given as many as I could. The point the reader should
note is that the rosettes of these spotted animals become dark rings
on the tail, alternating with rings of the general ground-colour.

Having studied these rosetted Cats, we are now in a position to
understand their relation to s¢rzped Cats.

There are numbers of small Cats and Genets with their spots
arranged in longitudinal order, and others, as may be seen in
Fig. 27, with them arranged in transverse order.

This happens frequently, not only in the Cat tribe, but in other
animals also, as may be seen in Appendix A, Nos. 16, 17, 18,
and others.

I have said that it will not be difficult to show that the striped
animal is only a modification of the spotted one.

I have already shown that in the Ocelot spots run into longitu-
dinal stripes and bands. Now I shall endeavour to show that the
stripes of the Tiger are no other than the fusion of transverse strings
of spots, so transformed as to have lost all semblance of their spot
origin.

The striped animals par excellence are the Zebras and Tigers,
with the minor Tiger Cats. With the Zebras I shall deal in an-
other place.

1In the Animal Kingdom of Baron Cuvier, Mr. Edw. Griffith, in vol. ii. p. 444, gives
a pure white Tiger, with only a shading of stripes.
36 STUDIES IN THE EVOLUTION OF ANIMALS

Fig. 21 is the picture of a living Tiger, and Figs. 22 and 23 are
the pictures of two very differently marked Tiger skins. It will
be noted that on all three there are some spots which have not
coalesced into stripes.

A glance at the spots of the living Cheetah and of the Cheetah
skin (Figs. to and 11) will show that in many places they are
arranged in transverse rows, viz., on the flanks and on the fore-legs ;
the Leopard spots on the fore-legs are also arranged in rows. A

 

 

Fic. 21.—Picture of a living Tiger, from a photograph by Ottomar Anechiitz.

very little change will make the spots closer, and a further change
will first amalgamate them into beady strings? and then turn them
into bands, as we have seen occur in the Ocelots ; only in the Tiger
and certain Cats the bands are transverse and their margins are
sharp, while in the Ocelot they are longitudinal and their margins
are scolloped.

It is very strange that spots in certain animals, and in certain

1 In a previous note I mentioned having seen Cheetah spots run into beaded strings.
SPOTTED AND STRIPED MAMMALS 37

parts of the same animal, very frequently show a tendency to
arrange themselves in either longitudinal or transverse orders, and
often coalesce into stripes. When irregularly disposed rosettes

 

Fic. 22.—Tiger skin, from a photograph by Messrs. Dixon and Son.
Skin lent by Messrs. Jeffs and Harris.
coalesce, they form the large patches of the Clouded Tiger /.

diardi) of Elliot’s monograph.
What is still stranger is that the black rings of the rosettes
 

Fic. 23.—Tiger skin, from a photograph by Messrs. Dixon and Son.
Skin lent by Messrs, Jeffs and Harris.
SPOTTED AND STRIPED MAMMALS 39

coalesce with other black rings, and form a larger ring-or band
outstde the amalgamation, and the. brownish enclosed’ spaces

 

FIG. 24.—Tiger skin showing twin stripes. Photograph obtained from Messrs. Russ
and Winckler, of Edinburgh.

coalesce and remain zuszde the patch or band, as in the Clouded
Tiger and in the Ocelot.
40 STUDIES IN THE EVOLUTION OF ANIMALS

Fig. 25 shows various degrees of transformation of spots into
stripes and blotches on the legs of certain carnivora. On the
other hand, we should not forget to note that on the legs of striped

 

Fic. 25.—a and 4, fore- and hind-feet of a tiger; c and d, fore-feet of two different
leopards ; ¢ and /, fore-feet of two different lynxes. From Coloration of Animals and Plants,
by Alfred Tylor.

animals sometimes all markings disappear. In the window of a
furrier I have seen a young tiger with plentiful stripes on its hind-
quarters and almost none on its shoulders and fore-legs ; and we
know also that the Quagga (Fig. 54) is plentifully striped on its
front parts and has no stripes at all on its haunches and hind-legs.
SPOTTED AND STRIPED MAMMALS 41

I have seen a Leopard skin with crowded rosettes, several of
which were fused into one oblong ocellus, as shown in Fig. 15, 6.

This fusion will afford some idea of how the parallel twin
stripes of the Tiger skin of Fig. 24 may have originated. Fig. 26
gives a diagrammatic sketch of some spindle-shaped ocelli I saw
on a Tiger skin.

A row of Leopard rosettes, as shown in Fig. 20, d, may easily
be transformed into a pair of twin and parallel transverse stripes.

gy

ae |

=

Fic. 26,—Spindle-shaped ocelli on a Tiger skin; a—é represents the spinal line,

We have already seen that similar twin bands do actually
occur in the Ocelots from rosettes disposed longitudinally.

The reader should especially note that in the figure of the
living Cheetah the spots on the tail have gradually coalesced, and
formed continuous rings towards the tip. These ringed tails occur
whether the animal be spotted or striped, and in the figure of the
living Tiger the rings on the tail are doudle, indicating their origin
from rosettes ; and indeed in Fig. 24 almost all the stripes on the
body are double. This may be considered conclusive evidence
that the stripes of all Tigers, however modified they may be,
42 STUDIES IN THE EVOLUTION OF ANIMALS

originated from. rows of Leopard rosettes. We may note further
that. in the Jaguar skin (Fig. 4) the spots on the chest have

 

Fic. 27.—-Markings of different small Cats, from a photograph by Messis. Dixon and Co.
Skins lent by Messrs. Back and Co.

coalesced into beady stripes, and we know that the separate ring-
spotlets of the Jaguar rosettes in other Leopards do coalesce into
a continuous polygonal ring.
SPOTTED AND STRIPED MAMMALS 43

Then in Fig. 27 we have a striking series of transitions if the
smaller Cats from spots to stripes. Some specimens show only
spots on the flanks; others, spots coalesced irito wavy or beady:
stripes ; and others show more finished stripes, like those of Fig.
28. In the British Museum enclosure there is a Domestic. Cat
which I often stop to look ,
at. The posterior half of its
body is spotted ; the anterior
half is striped transversely ;
theneckand head are striped
longitudinally ; the legs are
striped transversely, and
also spotted. Then along
its spine it has a broad black
band, and its tail js,ringed
in its terminal half” Here

 

Fic. 28.—Striped Cat, from a photograph by
. ae Messrs. Dixon and Son. Near the root of the tail
ised marking, combining a _ it has-a few rosettes.

we have a sort of general-

little of each of the special

features of distinct races of animals, the black band along the
spine in some animals being possibly the only vestige of ancestral
spotting ; while the ringed tail in the Racoon is the only ay
left to tell the tale of its ancestral markings.

In the International Fur Stores I saw the skin of a Tiger which
had-a large ocellus towards the ventral region. This same skin
had a modification of stripes on the lumbar region, as if the
pigment were undecided whether it would run into separate stripes
or form an ocellus. Then in another Tiger skin I saw on one side
a curious rosette, and on the other a pair of parallel stripes.. Both
these abnormalities in the: Tiger markings are given in Fig. 29:
(No. 1). They are not only curious, but very suggestive.
44 STUDIES IN THE EVOLUTION OF ANIMALS

If one had the opportunity of examining hundreds of skins of
Leopards, Cheetahs, Tigers, and Cats, I have no doubt whatever
that a perfect series might be picked out which would easily
prove the transition from spots to stripes. The examples which
I have given, I think, are sufficient to convince any one of the
relationship of stripes to spots and rosettes.

A word about the tadpole-shaped ocelli on both sides of the

 

No. 1.
he c
afoul LLL le bo
2 ——
Life hh; "; TRE
i My UT x
iff y" “yy TiO oT
Ly DIT aa LN Mle ED:
No. z
Fic. 29, No. 1.—(a) Large ocellus near ventral region
of Tiger skin; (4) combination of a curious ocellus and
a pair of stripes ; (c) the spinal line.
No, 2.—(a, 6, and ¢) Transitions from simple stripes
to ocellated stripes of the Tiger, as seen in Figs, 22
and 23.

Tiger skin of Fig. 23. I do not think that these are enlarged
and spindle-shaped Leopard rosettes, although in Fig. 59, No. 5,
I have given one which has turned into a deaked ocellus. I
think that the Tiger marks in question have a different origin.
Tiger stripes are sometimes parallel throughout their whole length,
as seen in Fig. 24; but at other times the stripes are shifted
so as to make one commence about the middle of the other,
as in the lumbar region of Fig. 21. By approximation and
partial fusion, two stripes thus shifted would make a spindle-
SPOTTED AND STRIPED MAMMALS 45

shaped figure, with an ocellus in the middle; if the ocellus were
closer to one end, the figure would become not unlike the outline
of a tadpole, like those on the Tiger skin of Fig. 23.

No. 2, Fig. 29, is a diagram intended to show the transforma-
tion from simple stripes to spindle-shaped ocelli.

I think I have said enough (and perhaps more than enough)
regarding the striping of Tigers to show that it is simply an
extreme modification of the Jaguar and Leopard rosettes. But
if the reader should have any doubts about the descent of stripes
from spots, a glance at the small Cat skins of Fig. 27 ought to
convince him that the view I have taken of the genesis of stripes,
in the Cat tribe at least, is in all probability the r¢ght one. We
see separate spots passing into beady stripes and finally into
Tiger stripes on the hind-legs, On the shoulders of the small
Cats the striping is so fine that it is rather a brindling.

Then in the Natural History Museum, among the Cat family,
there are numerous specimens which show simple spots, mixtures of
spots and stripes, and simple stripes either transverse or longitudinal,
and also transitions from the one kind of marking to the other.

I might have dispensed with such a multiplicity of facts in
support of what I said; but to the general reader, who may not
be in the habit of seeing at a glance the obviousness of a con-
clusion, they may be useful in bringing home to him the truth
that stripes are evolved from rosettes.

If now we turn to other animals, such as the Deer and the
Antelope, we shall find that spots and stripes are interchangeable
and intermixable.

Fig. 30 shows the spotted young one of a Deer in the
Zoological Gardens; the adult showing no spots whatever.

1 In the Edinburgh Museum of Science and Art there is a good specimen of a
young spotted Wapiti (Cervus Canadensis).
46 STUDIES IN THE EVOLUTION OF ANIMALS

Then if the reader will:turn to the Review of Reviews of March
15, 1893, where a character-sketch of the great African hunter,
Mr. F. C. Selous, is given, he will find on p. 258 a Kudu Bull
beautifully striped, with no spots, and on p. 260 an allied
Antelope, the Bushbuck of the river Chobe, which is striped
and also spotted. Of the latter a fine illustration is given in

 

 

 

Fic. 30.—Shows the young of a Deer covered with spots, while the adult has none;
taken from a photograph, Zoological Society's Gardens.

the Roy. Nat. Hist, vol. ti. p. 277. See also Appendix A,
Nos, 20, 21, 22, 23, and 25, of this book.

The changes from spotting to nothing in the same individual,
and from spotting to striping, or a mixture of both, in the same
genus of Antelopes, is very remarkable. For some reason the
spotting of the adult of Axzs maculatus, shown in Fig. 14, is not
obliterated, although in the Deer of Fig. 30 no sign of spotting
remains in the adult.
SPOTTED AND STRIPED MAMMALS 47

It will, however, be preferable to let Mr. F. C. Selous! speak
upon the ‘question of spotting and striping in the Antelopes of
Africa. It would appear that not only age, but’ the cliniate and
food of a locality, may have a good deal to do with. me ene
in the markings of the skin.

Of the Bushbuck (7vagelaphus sylvaticus, Sadun.) he says:
‘In the Cape Colony, the adult male is deep dark brownish-black,
with two or three small white spots on the haunch, and ‘one
or two on the shoulder; the adult female is light’ reddish-brown,
with white spots on the haunches, and sometimes a few between
the shoulders and flank ; the young males are reddish- prow and
more or less spotted. °

‘On the Limpopo, however, the adult males are brownish-grey,
‘often wethout a sign of any spots; and thé young females are
more spotted than old ones. The adult females are of a dark
red, with a few white spots; the young males are a good deal
‘spotted, with a few transverse stripes.

‘On the tributaries of the Zambesi, east of the Victoria’ Falls,
-the male Bushbucks are of the same colour as the young males
‘found on the Limpopo, being dark red thickly spotted on the
haunches, shoulders, and sides, with ssa// white spots, and with
‘three or four faint white stripes down each side. ‘The adult
female is pale yellowish red, beautifully spotted, and with a few
white stripes.’

Then of the Bushbucks on the Chobe Mr. Selous says: ‘The
-adult males are of a very dark red colour, most beautifully spotted
with darge white spots, as many as fifty on each side in some
individuals, and in some cases as many as eight well-defined
-stripes. In addition, they have a mane of white hair three
inches long, from shoulder to tail, which can be erected. Young

1 4 Hunter's Wanderings in Africa, p. 209.
48 STUDIES IN THE EVOLUTION OF ANIMALS

males are of a pale red-yellow, with spots and stripes much
more faintly marked than in the adult animal, The adult
female is of a rich dark red, beautifully spotted with white, and
with three or four faint white stripes on each side, and a dark
spinal line. The young female is of a lighter red, and not so
much spotted. In Cape Colony and on the Limpopo, young
Bushbucks are more spotted than adults; they gradually lose
their markings as they become older; while on the Chobe and
on the tributaries of the Zambesi this order of things is reversed.
Adult animals are far more beautifully marked than young ones.’

Then of 7ragelaphus Spekit (Sclater) he says: ‘A foetus had the
skin striped and spotted yellowish-white, as in the adult Bushbuck
of the Chobe. Another recently born had a lighter colour, and
fainter spots and stripes; the adult is of a uniform greyish-brown
without either spots or stripes.’

From all this it would appear that the spotting and striping of
the Bushbucks does not depend on either age or sex, and that the
individuals of this genus differ much in marking and colouring ;
but, although differing so much as to become almost distinct
species, physiologically they remained ome species; and, living
together in the African bush, they must have crossed and have
become mixed up, so that the life-history of oze individual seems
somehow to give successive photographs, as it were, of the life-
history of the race.

Anything more bewildering than the facts placed before the
reader by this hunter-naturalist of Africa cannot well be imagined.

It is impossible to read Mr. Selous’ book and not feel convinced
that these Antelopes, when living for months in waterless tracts,
are at the mercy of their surroundings, not only for their life, but
also for the physiology of their skins. For at p. 207 he says
that in some parts of the country, for several months in the year,
SPOTTED AND STRIPED MAMMALS 49

there is absolutely no water, and Elands, in common with Gems-
buck and Giraffe, live and thrive there, and appear to do better
than in well-watered parts of the country. He thinks that in the
dry seasons these desert animals get the necessary amount of water
by eating a watery melon, which is plentiful, and a white watery
bulb, looking much like a turnip.

‘Among Antelopes, we have the head of a Kudu with three white
Spots on its cheek. Then in Appendix A, No. 27, is shown one
solitary broad stripe on the hind-quarters of the Waterbuck. These,
like the ring-tails of many animals, I take to be simply vestiges of
more extensive ancestral spotting and striping. Indeed, climate,
food, and age may have a great deal to do with the retention or
disappearance of spots and stripes. We see that in the Deer of
Fig. 30 the spots wholly disappear with age, while in these two
Antelopes all spots and stripes disappear, excepting, maybe, three
cheek spots in the one and one haunch stripe in the other.

“Mr, Selous says: ‘In the Mashura country every Eland cow is
plainly striped. One had nine broad white? stripes on each side.
Elands that are much striped have a whitish mark across the nose,
like the Kudu. Old bulls have no stripes. Great variations occur
in this: respect.’

Again turning to Dogs, we find that spotting and striping are
found among them also.

Fig. 31 shows a distinctly spotted Dog? Whether the Dog got

1 Shown in Mr. Selous’ book, in vol. ii. figs. 1 and 2.

’ It should be noted that in certain mammals, such as the Tiger and Zebra, the
stripes are Jack: while in these Antelopes the stripes are whz’e. Both spots and stripes
are liable to change from black to white, or vice versd ; that is, white becomes melanoid,
and black becomes albzno7d.

3 In the Natural History Museum there is a Phalanger—a marsupial—spotted much
in a similar manner. In the Zucyclop. Brit. the picture of a flying Phalanger is given
with transverse stripes on its back. In Somerset I saw a sucking Pig which was spotted
almost like some Dalmatian Dogs, but the spots were larger.

D
50 STUDIES IN THE EVOLUTION OF ANIMALS

this spotting from some mammal allied to the Cheetah, or not, I do
not know. Canine and feline animals are rather closely allied.

Moreover, both the Cheetah and the Dog want the retractile claws
of the Cats proper.}

 

 

 

Fic. 31.—Dalmatian Dog, from a photograph by C. R., 54.

Fig. 32 shows the Dog-spots fused into blotches not unlike the
consolidated rosettes on the abdomen of Leopards. In the Science
and Art Museum of Edinburgh there is a large Boarhound with
the Dalmatian spotting agglomerated into even larger blotches.

' Among Hyzenas there are species which are distinctly spotted, and others distinctly
striped ; although in Hyzenas the claws are well developed, they are non-retractile.
SPOTTED AND STRIPED MAMMALS 51

Probably this is only a preliminary step to piebalding, which is so
common in Dogs. It is conceivable that if this attraction of black
spots for each other increased, we should soon get the piebald
colouring of the Fox-terrier
and other breeds.

At Worthing I saw a
curious hybrid between a
Bloodhound and a Dalmatian
Dog—at least, its owner so
stated. Its legs were white
with well-defined tan spots;
its back and flanks were white
and thickly spotted with
black ; and those on the flanks
were grouped in threes and
fours, not unlike the consoli-
dated rosettes on the abdomen
of the Jaguar and Leopard ;
while its head was white,
spotted with tan. It showed
a curious persistence of spot-

 

. FIG. 32.—Blotched Danish Boarhound, from
ting ; but where the tan colour a photograph by Messrs. Dixon and Son.

of the Bloodhound came in,
the spotting of this Dalmatian hybrid became tan-coloured !

Then in the streets of London I saw another Dog of the
Dalmatian breed. A large number of the dorsal spots amalgamated
into a large black patch; half its face was spotted as usual, and the
other half wholly black.

On another occasion I met two Dogs of this same breed, pro-
bably brothers. One was almost wholly black, with some re-
maining white inter-spots, and half its tail was spotted with black ;
52 STUDIES IN THE EVOLUTION OF ANIMALS

while its companion had the black spots quite close to each other,
though much more distinct.

Then in Hyde Park one day I saw a curious Toy-terrier. It
was of the black-and-tan, short-haired breed ; but the parts that are
usually wholly black, in this case were gvey, blotched and striped

 

 

Fic. 33.—Brindled Dog, from a photograph by C. R., 847.

with black. It was not unlike the black-backed Jackal of the
Zoological Gardens.

Fig. 33 is that of a Brindled Dog. Here the stripes are unlike
those of the Tiger—that is, not so decided, but more like the
brindling on the shoulders of the small Cats in Fig. 27. The stripes
of the Dog are much finer and dissociated ; but in the streets I have
SPOTTED AND STRIPED MAMMALS 53

3

seen brindled Bull-terriers which had closer and broader stripes,
with some which were broken up into fine lines ; and in some cases
many of the stripes were distinctly in pairs, suggesting some origin
similar to those on the Tiger skin of Fig. 24, and presumably there-
fore the twin stripes in the Dog must have been caused by a similar
modification of rosettes.

Mr. Rawdon B. Lee, in his book on Modern (Sporting) Dogs,
gives a good figure of a Danish Boarhound with conspicuous
stripes.

In brindled Dogs we have to note that the stripes on the limbs
follow the direction of the limbs, and are not transverse to them,
as in Cats, Zebras, and striped Hyenas. In some Tigers I have seen
a tendency to a similar disposition of the limb stripes. This, how-
ever, need not embarrass us, as we have already seen that, in the
Cats, spots may group themselves into stripes either longitudinally,
or transversely, or diagonally. Brindled Dogs are to be found in
various races—in Greyhounds, Boarhounds, Bulldogs, etc.

In the Viverrzde@ there is presented a similar study. We see
large spots breaking up into numerous small ones, or perhaps the
reverse |—that is, small ones agglomerating into large ones ; also
spots stringing themselves into stripes, longitudinally on the body,
and transversely on the legs.

In several species of the Mungoose a complete intermixture of
pigments seems to have occurred, so as to produce a sort of grizzly-
grey coat; while in the Zebra-Mungoose and in the banded Mun-
goose, both of East Africa, the spots have arranged themselves in
stripes and bands transversely (see App. A, No. 15). In Galdea,
however, we see a wholly brown surface, with a few black rings on
the tail, as a vestige of ancestral striping or spotting.

What we have to note very particularly is that the Indian Civet

1 See Appendix A, Nos. 9 to 12.
54 STUDIES IN THE EVOLUTION OF ANIMALS

(Viverra zibetha) in the Science and Art Museum of Edinburgh
has Leopard rosettes on its haunches, simple spots on its shoulders,
and marblings on its flanks! and that the Spanish Lynx (Fe/ss
pardina, Oken) has Leopard rosettes on its haunches, and simple
spots over the rest of its body.

After having passed in review so many spotted and striped
mammals, we may perhaps be in a position to divide their
markings into—

(a) Spots and groups of spots forming rosettes, or solid
blotches.

(6) Stripes or bands of various breadth, either transverse,
diagonal, or longitudinal.

(¢) Marbled or clouded markings, like those of some Cats.

(2) Piebald markings, like those of Dogs, Cattle, Horses, etc.
And finally we have

(e) Self-coloured animals, which present a total obliteration
of spotting and striping. These may be subdivided into pure
selfs, without a speck of any other colour; selfs with vestiges of
spotting ; selfs with ringed tails; and selfs with points of other
colours, such as we see in Horses, Dogs, etc. The dun-coloured
Cat, with black points, is a very interesting variation. It is seen
in exhibitions.

From the study of all the foregoing, I have come to the con-
clusion that each ancestral rosette, originally composed of a ring
of isolated spots, has in time undergone the following marked
modifications, some of which are found in the same animal, and
others in distinct individuals :—

(a) The isolated spots have fused into continuous rings, or
segments of rings, as in many Leopards.

(6) The ring has contracted into a large spot, with obliteration
of the enclosed space, as in the Serval and others.
SPOTTED AND STRIPED MAMMALS 55

(c) The rosettes, sometimes many of them, have fused either into
large bands or patches, as in the Ocelot and marbled Cat.

(2) The consolidated spots, after arranging themselves into
rows, either transversely, diagonally, or longitudinally, have fused
themselves further into stripes, as in the Tiger, the ‘Tabby Cat,’
the Pampas Cat, and certain Civets.

(e) The rings on the tail have followed the same course of
modification ; the consolidated spots have fused into rings, or the
rosettes have fused into twin rings, as in the Margay; these, in
some descendants, have then amalgamated into broad bands.

(f) Finally, the rosetting, spotting, or striping has been entirely
obliterated from the adults of certain species, such as the Lion,
the Puma, the Caracal, jet-black and albino Cats, and others, while
in the young of some the spotting remains distinct! The rusty-
spotted Cat ‘is quite peculiar among spotted Cats in having the
tail without either spots or rings ;’ while in some mammals, as in the
Racoon and the cunning Bassaris, the only vestiges of ancestral
spotting or striping are the ‘ rings on the tail.’

* Young Lion cubs are usually spotted; but Mr. Edward Griffith, in he Animal

Kingdom of Baron Cuvier, vol. ii. p. 447, gives two Lion-Tiger cubs, three months old,
striped like Tigers.
DAPPLED AND STRIPED HORSES

AND SOME OTHER MAMMALS
‘The first master strikes out a luminous idea, and writes a great book which promises
speedy results ; but after his own generation has been dazzled by it, comes the criticism
of the next : exceptions, and violations of his laws, are discovered ; the large views which
he stated with convincing clearness become misty and obscure; and men set themselves
to rediscover, in some new way, generally with poor and shabby minuteness, and with
many modifications, what was once an accepted theory.’

The Present Position of Egyptology, by Professor MAHAFFY,
Nineteenth Century, Aug. 1894, p. 269.
PART II

DAPPLED AND STRIPED HORSES

AND SOME OTHER MAMMALS

FOR my purpose, under the term Horse I include all animals that
come under the denomination of the genus Eguus.

In the Leopards and Tigers it was easy to show the derivation
of stripes from spots or rosettes. There is, however, a domestic
animal which is differently marked from Leopards. I mean the
dappled grey Horse shown in Fig. 34. He has a congener—the
Zebra—in which the stripes are quite phenomenal. In these
animals it is not so easy to trace the striping from spotting,
although, I think, it can be done.

There are three distinct varieties of fu/ly dappled Horses like
that shown in Fig. 34, viz., the white Horse reticulated with grey,
the dun Horse reticulated with black, and the brown Horse also
reticulated with black The markings of the dun or sponge-
coloured Horse are very striking. They are all called dappled
Horses in the trade—grey, dun, brown. I have called the darker
pigment reticulation, because it appears as if a net were thrown
over the fully dappled Horse, leaving the meshes filled with either
white, dun, or brown.

The dappling or spotting of the domestic Horse is so persistent,

1 Not improbably the dun and the brown dappled Horses are me/anozd variations of
the grey dappled Horse.
‘(0d eg proy uopuocyT ‘asvuew ‘yng ‘qd IN
jo uorssiuied pury fq vexe3) ypuqesy) “yA hq ydesSoioyd v Woy ‘asioZy snqrumo AaiZ_ patddeq—'té ‘org

 
DAPPLED AND STRIPED HORSES 61

that we see it, more or less, going through all the changing
colours of Horses ; and it would be almost as hopeless to give
distinct names to all the variations of colour in Horses, as it would
be to name all the shades of colour in domestic Pigeons. The very
fact that the dappling is so persistently inherited, either wholly or
vestigially, would indicate that it

comes from the very foundations

  
    

: Fa

of Horse evolution. ee oe

I have not been able to dis- ee) »? EN
cover that any existing species of DY cigs 2) ») ) \
the genus Equus, in the weld state, Gh ee. ) a 2D
is dappled. 2 D+ c mg Se

The earliest record ofadappled ~~~ ee ee |

ee

Horse, in a state of domestication,

a

eel
Suge
/
tN
a ae
iad

that I can find is taken from a
Spanish MS. of the eleventh cen-
tury. The quaintness of its mark-
ing is shown in Fig. 35, and the
author thinks it was of the Arabian
breed. The markings are most ie
oe ae ae Hapeles Fic. 35.—Spanish Horse, from Horses
Horse, because the colours are y¢ 4nriguity, by Ph. Ch. Berjean (p. 23,
in black and white; but the ™S. xi. Cent.).

dappling is traceable in the bay,

the chestnut, the brown, the black, the roan, the cream, the dun,
etc. etc. The pure white, the pure black, and other pure self-
coloured Horses may be free from traces of dappling ; but the vast
majority of Horses are either fully dappled, or have ¢races of
dappling, and these are most persistent on the hind-quarters,
round the root of the tail. The Horses of the 2nd Life Guards
are either black or nearly so. I noticed that those which took
62 STUDIES IN THE EVOLUTION OF ANIMALS

part in the escort at the opening of the Imperial Institute were
almost all dappled on the hind-quarters, round the root of the tail.

In dun?! or sponge-coloured Horses, the dappling in this par-
ticular region is often amalgamated into a sooty-black patch on

 

Fic. 36.—Dappled grey Cart-horse, from a photograph by Mr. Stanborough, of Bexhill-
on-the-Sea,

each side of the tail-root; a similar sootiness results from the
fusion of dappling along the upper ridge of the neck.

Some grey Horses are very distinctly and strongly dappled,
such as those given in Figs. 34 and 36, I think it very beautiful

1 Mr. Darwin defines dun as ranging from ‘between brown and black to « close
approach to cream-colour’ (Origtz of Spectes, 1888, p. 200).
DAPPLED AND STRIPED HORSES 63

to see a pair of finely shaped grey carriage-Horses prettily spotted.
Should any of them die, their skins would make pretty rugs.
Unfortunately, for some reason, spotted Horses are not fashionable,
and do not appear to be kept for breeding purposes.

In some instances the dark reticulations are all over the body,
but more conspicuous on the flanks, the dappling on other parts
being often modified. The white dapples of the grey Horse
can be seen to vary from irregular patches to small spots. In
some regions, such as on the fore- and hind-legs of Fig. 36, the
smaller dapples seem to have amalgamated into large fern-like
patches. In other cases, such as those on the fore-leg of Fig. 34,
the dapples have degenerated into star-shaped marks, which often
dwindle into minute specks like those on the flank of Fig. 39, all
the rest of the ground being of a dark grey, and in some cases
almost black. Indeed, we might say that the two extremes of the
grey dappled Horse series were—(a) a white Horse with traces of
grey reticulations, and (0) a Jdlackish horse with traces of white
spots. In other words, the grey reticulations that isolate the
white dapples of the grey Horse can be obliterated, either
wholly or partially, and the Horse made either wholly wh7¢e, or
white with vestiges of dappling. On the contrary, the white
dappling may be obliterated, and the Horse made either wholly
dark grey or dark grey with vestiges of white spotting. The
star-marks on the fore-legs of Fig. 34 should be compared with
those of Fig. 36.

The invasion of the white dapplings by the grey reticulations
is partially seen in Fig. 37.

Few, I venture to say, have any notion how much may be learnt
from Horses of all sorts which are to be seen by thousands in the
streets of the Metropolis. They are ready-made experiments for
scientists to take up and theorise about. Unless pure white,
64 STUDIES IN THE EVOLUTION OF ANIMALS

chestnut, or flea-bitten, there is scarcely a Horse which does not bear
vestiges, more or less pronounced, of dappling.

In Fig. 38 is given a spotted Horse, which shows the dappling
on the flank disposed in slanting rows; and Fig. 34 shows that on
the neck the dark colour tends to form dands.

 

 

Fic. 37.—Grey dappled Pony, from a photograph by C. R., g22.

Note that on the groin of both Horses of Fig. 38 the dapples
are being broken up into szznute specks.

When this occurs all over the surface, it probably gives rise to
what is called a ‘flea-bitten’ Horse, with either black or brown
specks.
DAPPLED AND STRIPED HORSES 65

I would ask the reader to note particularly the rows of slanting
dapples on the flank of the upper Horse of Fig. 38. I have already
referred to similar slanting rows of rosettes in certain Leopard skins
(Fig. 15, 2), and shall have to refer to them again.

No one, I think, will doubt that these spots in this Horse are
vestiges of the larger dapples, like those of Fig. 34. Ifa full-blown
dapple or rosette can be reduced to a mere point, as we see it in
certain Horses and other animals, it stands to reason that it can be
much modified otherwise.

We do not know what atomic conditions of the nerve-centres
are requisite to produce this minute specking, but it is evident that
a more complete intermingling of the pigmented hairs with the
white ones would give rise to a roan or a strawberry roan. On the
other hand, when the pigments agglomerate in separate large
patches, we get the same piebald conditions seen in Cattle, Dogs,
Pigs, etc.

I am not here going to enter into the intricate question of how
the dappling of the young Horse commences—whether by minute
spotting becoming larger, or by large patching dwindling eventually
into minute spotting. It is a difficult question to unravel, and
there does not seem to be any accurate information on this point.
As to how the dappled Horse originally came into being at all, there
would not seem at first any means of finding out. Fossils in no
way record the coloration and markings of the skins of extinct
animals. Nevertheless, I hope to throw some light on this point of
evolution later on. The existing wild congeners of the Horse are
either striped, like the Zebra, or self-coloured, like the Azang or wild
Ass. The coloration of the latter is a sort of tan or fawn colour,
while in the domestic Ass mouse-grey is a common colour.

The person who originally invented the names for the colours of
Horses must have been colour-blind, for how could he have called

E
 

Fic. 38.—Two Cart-horses, from photographs by Mr. P. D. Coghill of the Royal
Veterinary College, taken by kind permission of Mr. J. Poynter, Horse Department, Great
Northern Railway Company.
DAPPLED AND STRIPED HORSES 67

‘chestnut’ the colour of a Horse, which, if it were a Cow, would be
‘red. And to call a Horse ¢an-coloured would be simple heresy.
Nevertheless, what is called a golden-bay is nothing but a rich tan-
colour, which in other individuals shades off into the dun, the sponge-
colour, the cream, and the white ; while in another direction this tan
shades off into the chestnut, the bay, the brown, and the black.

All the experts whom I have consulted agree in saying that the
Horse, when recently foaled, is never dappled, but is of a uniform
dark colour, excepting albinos,

I asked a farmer who is a great hunter, and who has also bred
Horses, and has had ample opportunities of seeing young foals,
whether he had ever seen a recently born foal which was dappled.
He replied—not one. I am informed that the dappling, when it
does come, begins to appear when the foal is a few years old. This
is rather curious, for in the case of some Deer, as shown in Fig. 30,
the young one is plentifully spotted, while the adult has no sign
of spotting.

No one seems to have made any accurate observations on the
dappling of the Horse—when it commences, how it commences, and
how it proceeds, although there are many records of Zebra-striping
in the Horse. Among the thousands of Horses in the streets of
London, one sees all possible variations of dappling—from a few
spots to the whole body covered with maculations. Does the same
individual go through all these phases of dappling, or are certain
variations permanent? Does dappling commence gradually and
go on to its maximum extent, and then gradually disappear, or
how? A veterinary surgeon told me that the dappling varies with
every change of coat of the Horse ; and all seem to agree that as the
Horse grows.older the white colour increases and the dark colour

1 In the Natural History Museum there is a very young Jaguar which is wholly dows
without any spotting.
68 STUDIES IN THE EVOLUTION OF ANIMALS

diminishes. The chafing of the collar seems to have the same
effect; but in Fig. 39 and many others the reverse seems to have
occurred. Does sex make any difference in the dappling? A

 

Fic. 39.—Omnibus Horse with the spots becoming obliterated, leaving a dark-grey surface ;
from a photograph by Gabrielli, taken by permission of Mr. Duff, manager of the London
Road Car Company.

great deal is known about the powers of running of the Horse,
about his powers of draught, about his anatomy, his physiology, his
pedigree, and perhaps about his descent and relation to extinct and
living animals ; but very little seems to be known about the origin
and course of his dappling.
DAPPLED AND STRIPED HORSES 69

What is wanted is that some amateur with leisure and means
should undertake to photograph the dappling of the same Horse
as soon as this feature commences, and to photograph the same
Fforse on both sides every year, after the Horse’s change of coat.
So many leisured persons possess cameras, that this bit of work
ought to be an easy amusement.

If many were to undertake this work, so much the better. And
if the Horse were closely clipped after being photographed, and
then re-photographed, we might be able to discover how far the
pigmentation of the skin coincides with the dappling of the hair.?
We would then have some accurate data to build theories upon ;
and by comparing the dappling year by year, we might have the
revelation of some interesting facts. All these seem trivial things,
but from an evolutionary point of view they may be important.
However trivial a fact may appear at one time, it may one day
turn out of value.

This any one can see for himself, viz., that the colour of the
clipped Horse is much lighter than it is before clipping. Part of
the darkness of the old coat may perhaps be put down to dirt, and
part to the action of light and weathering. In some cases, after
clipping, the surface shows traces of dappling which it did not
show before ; and in roan Horses the clipped surface is often darker,
or lighter.

We seem to have more definite information about crustaceans,
fished out of the ocean from a depth of 3000 fathoms, than we have
of the changes in the colouring and marking of the Horse, an animal
which has been in daily use, in various ways, for thousands of years !

1 I saw a pink-white Horse in an omnibus. It had very little hair—indeed, it was
almost hairless; and on its shoulder it had dark pigment-marks in the sfzz, like those
of the hair-marks on a grey dappled Horse. Moreover, it had dark circular spots in

many parts of the skin, like those of the Dalmatian Dog, the rest of the skin being of a
blush-rose colour.
70 STUDIES IN THE EVOLUTION OF ANIMALS

Considering the millions of Horses that are bred everywhere,
both in a domesticated and also in a semi-wild state, it is astonish-
ing how little reliable information there is on this particular
subject. As TI said, from an evolutionary point of view this study
would be important, as the history of dappling in any individual
ought to tell some tale regarding descent.

In absence of any recorded accurate information, I have had
to explore the Horses in the streets of London and elsewhere, in
the immense stables of carrying companies, in Horse-shows, etc.
Wherever I could see any deviation which I considered of some
importance, I made a note of it on the spot.

Have you ever observed a‘ dappled sky’? The maculations
of some dappled Horses, such as those of Fig. 37, are not unlike the
patches of cumulus clouds with jagged edges, as they are often
seen close to each other in a ‘dappled’ sky, the intervening blue
sky corresponding with the network of dark grey between the
Horse-dapplings. Just as clouds are unstable, break up, and run
into each other, forming a uniform dense haze, so do the jag-margined
Horse-dapplings seem to change with age and from other causes.
The cloud-patches of the Horse often break up and deliquesce—to
continue the simile—as seen on the hind-quarters of Figs. 34 and 39.

This I found, and have confirmed it hundreds of times in
omnibus Horses. After severe exertion in drawing a loaded
omnibus, the superficial veins of the flanks, shoulders, and legs
start out. On the flanks they form reticulations which, in dappled
or partially dappled Horses, cozwcede with the dark reticulations.
In self-coloured Horses, such as pure whites, pure bays, etc., only
the venous reticulations are seen. But whenever there is a fine pig-
mentary reticulation of a different colour from the general colour,
the two reticulations cozzczde—the venous and the pigmentary.
In freshly clipped Horses all this can be seen very plainly.
DAPPLED AND STRIPED HORSES 71

In another place I have endeavoured to account for this
coincidence.

In Fig. 40 (No. 1) I have given a diagram of what might be a
portion of the flank veins of a Horse; and in No. 2 I have shown
the same pigmentary reticulations dvoadened by invasion of the
dark pigment, or, what comes to the same thing, by contraction of
the white patches. The broad reticulations still correspond with
the venous network, shown by dotted lines, which lies in the

No. z.

 

Fic. 40.—Diagrams of reticulations of flanks of Horses.

No. 1. (a) white patches; (4) dark reticulations, coinciding with veins.
No. z. (a) contracted white patches; (4) superficial veins.

middle of the channels between the dapples, and therefore are not
so conspicuously coincident with the network. When, however, the
pigmentary network is fine, it lies over and perfectly coincides
with the venous network on the Horse’s flank.

If you observe a dark-grey Horse and a white-grey Horse, you
will see that in the former the white spots are disappearing, and
mingling more and more with the dark-grey of the ground-colour,
to form a uniform grizzly-grey colour, as in the upper Horse of
Fig. 38; while in the latter the dark reticulations are lessening
more and more, and restricted to mere vestiges, mainly on the
72 STUDIES IN THE EVOLUTION OF ANIMALS

shoulder and haunch, as in the lower Horse of the same figure. In
many cases the white-grey Horse has nothing but the reticulations
of the superficial veins to mark the places of former pigment
reticulations, these having wholly disappeared, and having been
replaced by a wnzform white colour.

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Fic. 41.—(a) and (4) are from the right hind-legs of two different Horses; (c) is from a
light-bay Cart-horse (Whit Monday Show); (d) is a fern-like dappling over the superficial
vein of the fore-leg of a dark-brown Horse (Whit Monday Show).

Certain well-dappled grey Horses have a very peculiar mark,
like a fern-frond, which is pretty constant on the hind-legs, on the
fleshy part between the heel and &zee which is plainly visible in
Fig. 36. This also coincides with a similarly disposed venous
ramification on that particular part of the Horse’s hind-leg. In the
accompanying diagram (Fig. 41) are given three branching veins

1 Anatomical heel and knee are here meant, and not the veterinary terms.
DAPPLED AND STRIPED HORSES 73

which correspond with this curious fern-like mark, and also a bay-
coloured fern mark from the fore-leg of a brown Horse. The latter
would perhaps correspond to those interesting marks on the fore-
leg of Fig. 36.

The fern-like mark on the hind-leg of the grey Horse, when
present, is always situated in the same place, viz., on the fleshy
part of the hind-leg, in front of and a little above the hock.

On the legs of Horses the larger superficial veins have usually
a somewhat transverse disposition, while on the flanks they are
reticulate.

That the superficial venous distribution of the Horse has some-
thing to do with the pigmentation of its skin, I have not much
doubt; but what that ‘something’ exactly is I am unable to say.
Perhaps I ought to say the zerves of the veins have something to
do with the pigmentation of the skin.

I have ransacked all kinds of works on the Horse in search of
its general superficial venation, but have not found such a thing.
Indeed, Professor M‘Fadyean has told me that there has been yet
no such publication.

The following, however, may be interesting to the student of the
physiology of animal markings.

Nine months after I had written out my ideas on the origin of
the markings of animals, and after I had received the photographs
of a dappled Horse from Mr. Stanborough, of Bexhill-on-the-Sea,
I read an article in the Wzneteenth Century of April 1893, by Prince
Krapotkin, on ‘ Recent Science.’

On p. 687 he writes thus :—

‘Franz Werner’s researches upon the colouring of Snakes,
recently embodied in a separate work, show that the temporary
and irregular spots which appear in Fishes and Frogs under the
influence of artificial irritations are of the same character, and have
74 STUDIES IN THE EVOLUTION OF ANIMALS

the same origin, as the also temporary and irregular spots which
appear in other Fishes, as well as in several Tritons and many
Gekonides, without the interference of man. Some of the pro-
voked changes of colour do not entirely vanish after the irritation
is over, and they belong to the same category as the spots which
appear in many animals in youth and disappear with growing age.
Moreover, it is maintained that a series of slow gradations may be
established between the irregular spots, the spots arranged in rays,
and finally the stripes such as we see them in higher mammals
like the Zebra or the Tiger; and if these generalisations prove to
be correct, we shall thus have an unbroken series from the tem-
porary spots provoked by light or electricity to the permanent
markings of animals.’

I do not doubt that the pigments on the skins of animals are at
one end of the telegraphic wires (the nerves) which connect them
with the nerve-centres. Minute atomic changes, which, through age
and other causes, occur in the nerve-centres, influence electrically
the pigmentation of the skin ; but what we have to search for is why
all this is so. This investigation I have left for another place.

Let us now study a little in detail the dapplings of the grey
Horse.

In Fig. 36, at the joining of the shoulder and trunk, may be
seen several groups, consisting of a small roundish spot surrounded
by larger polygonal jag-edged spots, something like the enlarged
outlines shown in Fig. 42 (a).

In Fig. 38 (lower Horse) similar groups of maculations can be
made out on the Horse’s flank just behind the shoulder. Then in
Fig. 34 there are three well-marked similar groups placed in a line
slanting towards the abdomen, as well as several others.

In Fig. 42 (4) I have given two Jaguar rosettes for comparison.
Those of (2) and of (4) are very similar ; but I shall show in another
DAPPLED AND STRIPED HORSES 75

place that the components of these Horse dapplings are themselves
only a fusion of minor rosettes—which I take to be the true homo-
logues of the Jaguar rosettes.

Making allowance for the evolutionary deviations which have
certainly occurred during the descents of the Horse and the Jaguar
from their remote ancestral common stock, I hope to show that
their skin-markings also result from common ancestral markings,
although those of the Horse are now much altered. But so is his
skeleton altered; and his legs, by a superficial observer, would

‘<a
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Be oa
Ce bre
Fic. 42.—(a) Two rosette-like groups from the shoulder of Fig. 36; (4) two rosette-like
groups from the flank of a Jaguar, given for comparison ; (c) faint rosette-like dappling from
the neck of a whitish-grey Horse.

scarcely be considered as having any community of descent with
those of the Jaguar.

The spotting of the Horse would appear to be a transient
feature, changing with age, like that of certain ruminants ; while in
the Jaguar the spotting may be much more permanent, although I
am not aware that anybody has made any accurate observations
on the strict permanency or otherwise of the Leopard’s and
Jaguar’s rosetting. Judging from the specimens of very young
Leopard’s skins that I have seen, and from the very young Jaguar
and Cheetah skins in the Natural History Museum, I should be
inclined to say that the rosetting of these animals is not strictly
76 STUDIES IN THE EVOLUTION OF ANIMALS

permanent, although, looked at superficially, much alteration may
not be noticed during the life of the same animal after reaching
the adult stage. We know that in the Lion, the Puma, and various
other animals the spotting alters so much, that in the adult it is
on the verge of total obliteration.

In the dappled Horse the spots certainly tend to coalesce into

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Fic. 43.—Various forms of rosettes seen on Horses :—(a) from flank of grey dappled
Horse ; (4) seen on both sides of a grey Horse, near the root of the tail ; (c) from a Horse of

the Great Northern Railway Company ; (d and e) from dappled Horses ; (fand g) from hind-
quarters of an omnibus Horse; (4, 7, and 7) Horse-rosettes breaking up.

frond-like patches, or to break up into star-like or other small spots,
and even into minute specks, preparatory, it would seem, to total
obliteration.

In Fig. 43 I have given several groups of spots—rosettes, we
might call them—taken from various horses, which will elucidate.
what I have said above.

In this figure, it will be seen that in (2) the scolloped edges of
the patch break up into an aggregation of a number of dots, as in
DAPPLED AND STRIPED HORSES 77

(@and 7). A beginning of this may be seen on the groin of Fig. 38,
that is, at the junction of the haunch with the trunk. When
this breaking-up of the larger dapples extends all over the skin,
we get, as I said, what is called the ‘flea-bitten’ horse. Now and
again one sees a ‘flea-bitten’ horse which, on its haunches, has
ordinary dapples. This would indicate that the minute spotting
is only a modification of the dappled surface, and that the ‘flea-
bites’ are probably the breaking-up of similar large spots.

A still further and more complete mixture of the two colours

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FIG. 44.—Diagrammatic sketches of spots from various Horses :—(a) frequent disposition
of dapples on flanks of Horses (right side) ; (4) occasional triangular spotting on the flanks of
Horses (right side) ; (¢) rare spotting on the flank and haunch of a Horse (left side).
of a dappled Horse produces the uniform roan, whether a straw-
berry or an ordinary roan.

We have now to study another feature of the dappled Horse,
which is only a modification of the ordinary confused mottling,
if I may so call it.

As a tule, the flanks of the dappled Horse are simply reticu-
lated, without any apparent order. But in certain dappled Horses
the light-coloured spots on the flank occur in transverse rows,
with the dark interspaces modified into broad lines or bands,
both having the same slanting direction as the ribs, such as those
shown in Fig. 44 (a). These rows of spots are usually squarish,

1 These roans when newly clipped are often either bay-brown or black. Their heads
usually do sof roan.
78 STUDIES IN THE EVOLUTION OF ANIMALS

but in one case they were triangular, and seemed to fit into each
other as in (4). This disposition of the flank spots and inter-
spaces can, I think, be sufficiently made out in the dark Horse
of Fig. 38.

Moreover, in one particular Horse which I saw in the London
streets, the spots in the front part of the haunch
were also disposed in rows, which met the flank
rows at the abdomen, as shown in (c).1 Well, if
in imagination you amalgamate all the white
spots, you will have alternate light and dark
transverse bands, and those of (¢) would almost
reproduce the haunch and flank stripes of the
Zebra (Fig. 52).

This is not all, for I have not infrequently seen
that, in the modified dapplings of grey Horses,

Fic. 45.—Rough on the upper part of the leg the white stars
Senn ie, ae amalgamated into transverse irregular bands,
horse. while the dark reticulations also amalgamated

and formed alternate bands. J] have shown this
feature roughly in Fig. 45. It is also very partially noticeable
in Fig. 38 (upper Horse).

Further, on the neck of a light-bay pony at Bexhill-on-the-Sea,
and also on a butcher’s white pony in London, I have seen faznt
transverse stripes resembling those of the brindled Gnu. Then,
on the upper ridge of the necks of grey dappled, and more
especially brown dappled, Horses, the dark reticulations take the
form of short bands. Ina grey dappled Pony at the Horse Show
of May 1893, the upper ridge of the neck was marked as I have

 

1 The striped American Marmot (rctomys Hodi?) has each of its longitudinal
stripes made up of a string of whzte sguares on a dark ground (Animal Kingdom of
Cuvier, by Griffith, vol. iii. p. 186).
DAPPLED AND STRIPED HORSES 79

roughly shown in Fig. 46 (a), and the hog-mane was divided
into grey and white bands, just as it is in the Zebra, Then a
brown Carriage-horse, reticulated with black, had the upper ridge
of the neck as shown roughly in Fig. 46 (6), each space having
a spot of a lighter colour than the ground-colour.

But the best example I have seen of stripes in the domestic
Horse was on the 21st January 1894, in Piccadilly, opposite

 

Fic. 46.—(2) Hog-mane of a grey dappled Pony, Islington Horse Show, May 1893;
(4) markings on the neck of a dappled brown Carriage-horse.

Berkeley Street. A milkman’s cart had a Pony of a light-
bay or dun colour. The Pony had broadish black stripes on
his neck, shoulders, and flanks; he had also faint transverse
stripes above his wrists and heels. A rough sketch of him is
given in Fig. 47, which I took down at the time.

I have noticed that Ponies are oftener abnormally marked
than larger-sized Horses. They appear to have more direct Ass
and Zebra blood in them than the larger and more highly modi-
fied and artificially selected Horses.

Mr. Louis Robinson! suggests that the fossil Horse was about

1 North American Review, April 1894, p. 483.
80 STUDIES IN THE EVOLUTION OF ANIMALS

the size of the Shetland and Hungarian Ponies, and that these
appear to be more nearly related to the original Horse, while
the larger and more artificial breeds, like our breeds of Pigeons,
Dogs, etc., are further removed from the original wild stock.

At the Whit Monday Cart-horse Show, I saw a dark-bay Horse
with brindling on part of his flank, not unlike that of a brindled
Dog.

    

/}

Fic. 47.—Partially striped Pony of a dun colour!

In this connection we should remember that, when the Zebra
is crossed with the Ass, the striping, where it occurs, as is seen
in the Natural History Museum, is not a Zebra banding, but a
brindling, not unlike that of the Dog. (See Nos. 30 and 31,
Appendix A.)

Then in dappled omnibus Horses, along their spine, I have

1 A somewhat similar one is pictured on p. 322 of Stedy of Animal Life, by J. A.
Thomson, referred to further on.
DAPPLED AND STRIPED HORSES 81

frequently seen marks like those shown roughly in Fig. 48, which
are the marks we see along the spine of many Tigers, such as that
given in Fig. 22.

The remarkable black dappling on the dorsal region of the
white Horse given in Fig. 49 leaves little
doubt that those blotches and spottings

are broken-up Zebra bands. a

All the cases I have quoted go to es f “Re,
show that the dappling of Horses some- a ey
times tends to dispose itself in a kind a oe
of striping or banding in some parts Jat
which is not unlike that of the Zebra. oo,
But independently of any theories of

Fic. 48. — .\rrow-head marks

the genesis of striping in the Horse, _ atongthespineofsome grey dappled
Mr. Darwin, as a matter of fact, col- Horses.

lected a large number of cases of

Horses, which actually had stripes on their legs, their shoulders, and
even on their faces. Mr. J. A. Thomson! gives the figure of a
Devonshire Pony, from Darwin, with bands in certain parts which
are evidently vestiges of a much more extensive ancestral banding.

Mr. Darwin ® says, ‘I have collected cases of leg and shoulder
stripes in Horses of very different breeds in various countries from
Britain to Eastern China, and from Norway in the North to the
Malay Archipelago in the South. In all parts of the world, these
stripes occur far oftenest in duns and Mouse-duns.’

These are the colours of wild Asses, and it would appear when
these colours are reverted to, certain stripes, which belong to these
wild animals, often reappear.

In the Zoological Gardens there is a specimen of the Asiatic

1 Study of Animal Life, p. 322. Second edition,
2 Origin of Species (1888), p. 200.
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DA PPLED AND STRIPED HORSES 83

wild Ass (Equus onager). It is dun-coloured, with a broad spinal
band like that of Burchell’s Zebra, and faint transverse stripes
above the hoofs,

 

 

 

 

FG. 50.—Common Zebra, from a photograph by Mr, Gambier Bolton, F.Z.S.

The three Figs. 50-52 show with what perfection and complete-
ness striping in the skin can be evolved in the genus Aguas. They
represent three variations of Zebra, viz., the common Zebra,
 

 

 

 

 

Fic. 51.—Burchell's Zebra, from a photograph by F. G. O. S., roozs.

 
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Fic. 53.—Variation of Burchell’s Zebra, with obliteration of stripes on legs and haunch,
thus approaching the Quagga.
DAPPLED AND STRIPED HORSES 87

Burchell’s Zebra, and Grevy’s Zebra, a new addition from Somali-
land, which offers an astonishing example of animal striping.

At Mr. Rowland Ward’s establishment I was shown the skin
of what appears to be a variety of Burchell’s Zebra. It had the
broad striping and arrangement of striping characteristic of that
species, but the intermediate paler bands were of a milk-white
colour, and zthout any trace of those faint stripes between the
black bands. I noted also that some of the broad black bands °
were made up of the fusion of two narrower bands.

There is another variety which is only partially banded, viz.,
the Quagga, given in Fig. 54. The article on the Quagga in the
Encyclopedia Britannica (9th Edition) says: ‘In length of ears
and character of tail it more resembles the Horse than it does the
Ass.... The colour of the head, neck, and upper parts of the body
is reddish brown, irregularly banded and marked with dark brown
stripes, stronger on the head and neck, and gradually becoming
fainter, until lost behind the shoulder’ The haunch and legs have
no stripes,” and it approaches the character of Burchell’s Zebra of
Fig. 53. Indeed, it has been frequently confounded with the latter
by hunters. The Quagga was very common in South Africa, but
now is very scarce.

In my opinion, the Zebra stripes, like those of the Tiger and
other feline animals, owe their genesis to spots or rosettes or
dapplings, which had become disposed in transverse rows, some-
what like those on the Cheetah of Fig. 10, and on the legs of the
Jaguar of Fig. 4. Subsequently the rows of spots coalesced into
beady bands, and ultimately became the sharp-edged bands we see
in the Zebras.

1 It has also been found on the shores of Lake Rudolf (narrative of Count Samuel
Telekis’ expedition in Equatorial Africa). Figure of the skin in Proc. Zool. Soc. of London,
1890, p. 413.

2 There is a variation of this in the Science and Art Museum of Edinburgh.
        

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FIG. 54.—Quagga, from Cassell's Natural History—(by kind permission
DAPPLED AND STRIPED HORSES 89

The Zebra has arrow-head marks on its shoulder. The
domestic Cat of the British Museum, although partially spotted,
has similar arrow-head marks in the same place, so has the Cat of
Fig. 28, and the Tiger of Fig. 22, on the hind-legs. The rows of
spots on the fore-legs of the Jaguar (Fig. 4) are disposed in arrow-
head rows.

In the case of the spotted and striped Cats, as we have seen, it
is comparatively easy to make out the derivation of the Tiger
stripes from those of the Leopard rosettes ; but it is not so easy to
make out the derivation of the Zebra stripes from the spotting of
the dappled Horse.

I have endeavoured to develop this idea as far as I could by
means of existing examples which show the partial transition of
dapples into bands. Further on, in Fig. 56 (a, 4,c), 1 have shown
that originally the rosetting of the Horses must have been closely
assimilated to that of the Jaguar. The remainder must be left to
the imagination of the reader, taking into consideration analogous
transformations in the Leopards and Tigers.

We should note that the stripes in Zebras and Tigers, although
they are transverse on the trunk, those on the legs are not a con-
tinuation of those on the trunk, as in the brindled Dog, but are also
transverse, and correspond to the rows of leg spots of the Jaguar
and Leopard. This order of things I have tried to account for as a
result of inheritance from similar features in widely different
ancestors.

With regard to the Ass, the only cases I have seen with vestiges
of spots are those given in the Appendix C, Nos. 30 and 31. I
have, however, seen several little Donkeys at the sea-side which
had partial Zebra stripes.

Martin! says, ‘While speaking of the white colour of some

1 History of the Horse, by W. C. L, Martin (1845), p. 205.
go STUDIES IN THE EVOLUTION OF ANIMALS

breeds of the Ass, and the dappled markings of others, we may
observe that a variety with Zebra-like stripes upon the limbs, to
the very hoofs, is not unfrequently to be met with in our island and
elsewhere, and sometimes even a double cross upon the shoulders
is to be seen. To what cause the Zebra markings on the limbs
(and we have seen them strongly painted in mules) are to be
attributed, it is not easy to say. Is there, or has there been, a
striped wild Ass indigenous in Asia,! or does this style of marking
proclaim a cross at a remote date with some African species of the
Zebra section ?’

According to my view, all Horses and Asses and Zebras were
originally spotted, or have descended from spotted ancestors. A
large number among the domestic Horses have retained, or perhaps
re-acquired, their spotting. From the spottings there resulted
stripings. The Zebras have retained, or may have re-acquired, their
striping. The wild and domestic Ass has got rid of both spots and
stripes, but in some instances it has retained, or possibly re-acquired,
some vestiges of striping. The same may be said of the self-
coloured Horse, especially the dun-coloured Horse, the Kattiawar
Horse, and the Mule. They frequently show vestiges of striping,
and, as I said, the domestic Ass in two cases had vestiges of
spotting or dappling on their flanks.

When a character ceases to be useful, it begins to disappear,
and may become quite suppressed, while some other character
more useful may take its place.

Fig. 55 is a picture of a‘ Dhobi’s’ Donkey. I got it copied by a
native artist. The original drawing is now in the Lucknow Museum.
I have seen a somewhat similarly marked Ass in a picture which
was hung in the refreshment room of the Army and Navy stores.

1 We call the wild Assan dss, and the wild Zebraa Zebra, because they are differently
marked, but in reality they are both Asses.
DAPPLED AND STRIPED HORSES gt

The question might now arise—If the striping of the Zebra
is only a modification of some sort of ancestral Horse-dappling,

why have not the stripings of the Zebra any signs whatever of
their component spots or patches ?

 

     
   

 

Bowes

Ei cadumicsrien ss iaRe

 

Feipten

 

 

Fic. 55.—Picture of a Donkey in the possession of an Indian washerman.

Well, why have some Horses xo trace whatever of dappling ?
Of course the spotting disappeared like many other things that
become extinct. This disappearance is one of the great features
of evolution. Atrophy first and total suppression later on; and
g2 STUDIES IN THE EVOLUTION OF ANIMALS

in colouring first faintness and then total disappearance, if circum-
stances do not allow of a part, or a colour, continuing.

Moreover, many Tigers in their striping show no evidence of
its having originated from spotting. Yet if one makes a close
analysis of the striping of a number of Tigers and the spotting
of a number of Leopards, he can hardly remain unconvinced that
the striping of the Tiger, though primd facie without traces of its
origin, owes its genesis to ancestral spotting.

The reader may perhaps think that I have been drawing some-
what on my imagination, and seeing things which may not be
visible to others. But in the colossal museum of the streets of
London, if any one feels disposed to study this interesting subject,
by directing his attention to it, and by eeping his eyes open, he can
amply satisfy himself that what J have stated is founded on fact.

In this connection it may be instructive to tell a little story.
On one Sunday I accompanied to the Zoological Gardens a lady
who was a Fellow of that Society. In going through the Lion and
Tiger department, I pointed out how distinctly the Leopard spots
could be seen on the legs and abdomen of the Lion.

She said, ‘Do you know, I have been here hundreds of times,
and have never seen those spots before !’

It is impossible to find in the same Horse all the features I have
been discussing ; one may be found in one, and another in another,
because, like clouds, the dapplings shift ; but one has only to put
two and two together, and invoke the aid of the ‘law of proba-
bility, to come to conclusions similar to my own.

I have not, however, exhausted all the facts that can be
adduced in support of my contention, viz. that the dapplings of
the Horse are only greatly modified maculations of a nature origin-
ally not unlike those of the Jaguar, and that the striping of the
Tiger and Zebra have originated from the stringing together—neck-
DAPPLED AND STRIPED HORSES 93

lace fashion—of spots, like those of Fig. 38 (upper Horse), which by
further fusion were modified into clean-margined stripes. The
similarity between the stripes of the Tiger and the Zebra can be
seen at a glance; but the similarity between the spotting of the

2

 

Fic. 56.—(a) Rosettes from the flank of an omnibus Horse of a strawberry roan colour
(reduced); (4) rosette from the groin of a highly dappled grey Horse ; (c) one of many
rosettes on the flank of a dappled grey cart Horse; (¢d) marks on the flank of a brown
Horse.

Jaguar and that of the Horse is not so easily traced, and has to be
evolved with the aid of the imagination out of the variations pre-
sented by hundreds of specimens.

Nevertheless in Fig. 56 (2) I am able to give dona fide rosettes
from the flank of a newly-clipped strawberry roan Horse. They
94 STUDIES IN THE EVOLUTION OF ANIMALS

are the marks I had long been searching for, under the conviction
that, if my theory were right, I would discover them somewhere.
They are rarely seen, because in the Horse the components of each
rosette have fused into a continuous maculation, like those of
Fig. 34. (8) Isa solitary rosette with its central space split into two
portions ; (¢) is one of many similar rosettes on a Horse ; and (@)
were marks of a slightly different shade of colour from the general
coloration of the Horse. Those of (a) are almost exactly like my
restoration of the Jaguar rosettes of Fig. 70.

I do not, of course, mean that the dappled Horse will ever turn
into a Zebra ; or the rosetted Jaguar into a Tiger. But I do think
it quite conceivable that the striping of the Tiger evolved out of
rosetting like that of the Jaguar ; and that both the Zebra and the
dappled Horse may have evolved out of an animal with spotting
not unlike that of the Jaguar. As to the relation of the Horse-dap-
pling to the Zebra-striping, it only requires that one should keep
his eyes open in the streets to see on the neck of dappled Horses,
especially of Ponies, a decided tendency to Zebra-striping, which is
often continued into the Horse’s mane.

As I said, all experts agree that the Horse is born self-coloured,!
and whatever the cause may be, if this state of things continues,
the Horse will be a self-coloured animal ; otherwise he will be more
or less dappled. The variations and gradations in the appear-
ance and disappearance of spotting in animals are infinite. Some
acquire spots at different ages, others lose them at different ages.
Just as the embryo of the higher animals in evolving simulates
the different stages of form through which, in its race history, the
animal ascended, so the spotting and marking may give indication
of the ancestral markings through which that animal in its evolu-
tion may have passed.

1 Like the small Jaguar cub in the Natural History Museum—case 13.
DAPPLED RUMINANTS 95

There cannot be much doubt that the Kiang, or wild Ass,
originated from a Zebra-marked ancestor. In the Origin of Species,
p. 199, it is stated, on the authority of Colonel Poole, ‘that the
foals of this species are generally striped on the legs, and faintly
on the shoulder.’ In the adult they totally disappeared excepting
the spinal stripe. So have the markings disappeared from the
hind quarters and legs of the Quagga (Fig. 54).

Now let us turn fora moment from the Horse, the coloration
of which I think I have sufficiently discussed, to another set of
animals, viz., Giraffes and Bulls. From Fig. 57 it will be seen that
the large blotches of the Giraffe are separated from each other by
a lighter ground. These blotches may be nothing more than a
confluence of a number of rosettes, such as we see on the shoulder
of Fig. 34, or those on the fore-leg of Fig. 36. Indeed, on the
shoulder of one of these figured Giraffes (left one), there are two
blotches which seem distinctly to be made up of several smaller
blotches.

Cows and Bulls are rarely seen with any vestigial marks of
ancestral spotting or rosetting ; but the Bull of Fig. 57, on its flank,
shows distinct spotting not unlike that on the flank of the Horse
in Fig. 37. Then I think no one will say that the striking rosetting
on the flank of the Zebu of Fig. 58 is not almost identical with
that on the shoulder and fore-leg of the Horse in Fig. 36.

The very extraordinary marks of this Zebu, so uncommon
among domestic cattle, leave no doubt in my mind that the
ruminants and the Horse are more closely allied than may have
been supposed. Faint similar marks on the hump, abdomen,
and haunches, lead to the presumption that in some ancestral
ruminant the whole skin was covered with similar rosettes. Now
domestic cattle are either blotched, piebald, or self-coloured ; and
Deer and Antelopes are either spotted, striped, or self-coloured.
 

 

 

 

WEEK
AK

   

 

 

 

Fic. 57,—Giraffes and Bull, all three from photographs by Dixon & Son.
.DAPPLED RUMINANTS. 97

The Giraffe and the Zebu are the only ruminants, the one in a state
of nature, and the other domesticated, which continue to reproduce
distinct vestiges of ancestral skin markings, allied to those of the

 

 

 

 

Fic. 58.—Zebu, from a photograph, F. G. O. S., ro004.

Horse and the Jaguar. Indeed, if the rosettes on the flanks of the

Jaguar skin of Fig. 4 had their enclosed spaces filled up they would

become Giraffe blotches, and if we trim the rosettes of the Zebu and

fill in their scolloped margins, we again reproduce the blotches of

the Giraffe. In the Quagga we have seen that the stripes dis-
G
98 STUDIES IN THE EVOLUTION OF ANIMALS

appeared from the hind quarters and legs; so in the Giraffe we see
the blotches disappearing from the under surface and legs.

Recently a new Giraffe has been discovered in Somaliland, and
a description of it appeared in the Saturday Review of 21st July
1894, p.72. It is distinguished from the South African Giraffe ‘by
a complete and whole body colouring of rich bright chestnut (I
suppose the chestnut colour of the horse), scarcely separable by
very fine,! almost invisible lines of creamy white of hexagonal
shape ;’ while ‘in its South African cousin the markings are
widely and clearly defined, as seen in Fig. 57.

Hunters in South Africa have often described the Giraffe as of
a chestnut colour. This colour is common to the Horse and
the Ox. This ‘new Giraffe’ does not appear to differ from the ‘ old
Giraffe’ any more than one grey dappled Horse differs from another
grey dappled Horse. Compare different parts of the Horse in
Fig. 34. In parts the reticulations are fine, in others they are broad,
and in Fig. 37 they are still broader.

1 At Rowland Ward’s I was told that the divisions between the polygonal blotches
were about one inch broad.
MEANING OF THE JAGUAR AND
LEOPARD ROSETTES

AND OF THE MARKINGS OF OTHER MAMMALS
‘But, as soon as the attempt is made to think out the process in detail, we recognise
that here, too, we know nothing thoroughly, and that it would be uncommonly easy for
any one who wished to assign the processes of natural selection altogether to the realm
of phantasy to emphasise this view: for zt zs really very difficult to imagine this process
of natural selection in its detacls ; and to this day it is impossible to demonstrate it in
any one point.’

The All-sufficiency of Natural Selection, by Professor AUG. WEISMANN,
Contemporary Review, September 1893, p. 322.
PART ITI

MEANING OF THE JAGUAR AND LEOPARD ROSETTES
AND OF THE MARKINGS OF OTHER MAMMALS

THE groups of spots, or rosettes as they are called, which these
two animals present, are so characteristic that they must have some
meaning, which hitherto, as far as I am aware, has not been worked
out, or perhaps not worked out according to what, in my opinion,
is the true meaning of the rosettes. What can that meaning be?

The Leopard spots, as we have seen, are merely contractions
of those of the Jaguar; and may be the Cheetah spots are still
further contractions and modifications of those of the Jaguar.

The larger rosettes of the Jaguar consist, as we have seen, of a
certain space enclosed by a polygonal ring of spots (Fig. 4). The
space enclosed has either one or several still smaller spots,’ and
sometimes none; and its colour is often different from the general
ground colour.

In Fig. 59 I have given a number of variations of Jaguar and
Leopard rosettes, and also some groups of Cheetah markings.

It is perfectly clear to me that in Nos. 10 to 13, and others, a
fusion of some of the ring-spots has taken place, and a larger irre-
gular patch has been the result; that in Nos. 3, 4, 5,7 and I4,a

1 Ordinary Leopard skins sometimes show a few rosettes with specks in the enclosed
space.
102 STUDIES IN THE EVOLUTION OF ANIMALS

fusion of the whole ring-spots has occurred ; and that in Nos. 1 and
2 a still further fusion and contraction has resulted, ob/iterating the

 

FIG. 59.—Nos. 5, 8, 9, 12, 13, 19, 26, and 30-32 are from Jaguar skins; Nos. 33-35 are
from Cheetah skins ; all the rest are from ordinary Leopard skins.

enclosed space. Several of the rosettes indicate transition stages
towards partial or complete fusion. On the other hand, Nos. 26, 29,
30 and 31 would indicate a dissociation and tendency to scattering
of the component spots of rosettes.
MEANING OF JAGUAR AND LEOPARD ROSETTES 103

The solid rosettes, Nos. t and 2, and other forms of solid
rosettes, are to be found mainly along the spine and on the abdo-
minal surface ; while the dissociated rosettes shown in No. 32 are
from the shoulder of the Jaguar. For reasons to be seen elsewhere
I would consider No. 31 as the typical Jaguar rosette from which all
the other modifications have resulted. The fused ring, when it
occurs, may be either circular, polygonal, oval, or beaked, as seen
in Nos. 3, 4, 5, and 7. It will be seen that the enclosed space,
which is often of a different shade* from that of the general ground
colour, sometimes contains one or more minute spots or specks, as
in Nos. 27, 30, and 31.

Then No. 33 is a group from the flank of a Cheetah in the
Natural History Museum, No. 34 is from a similar animal in the
Zoological Gardens, and No. 35 is a group from the haunch of a
Cheetah in the Science and Art Museum of Edinburgh.

These rosettes have been taken from various skins, but I think
most of them can be matched from the skins of Figs. 4-7.

If the reader would take a pencil and draw outlines of the
different variations in the rosettes of the skins given, he would be
astonished with their variableness. Stretching of certain parts of the
skin might perhaps, as I said, partly account for dissociation, and
pressure and contraction might cause fusion, but I do not pretend
to explain how all this occurs. Some idea of the process may per-
haps be got by stating that in the embryo, while all the parts are
semi-fluid, the pigment cells attract each other and fuse into bigger
drops, just as minute discs of oil floating on water would now and
again fuse into bigger discs if they came in contact, or would
form groups of discs huddled together, and separated only by a
capillary film of water.

This obviously would not account for the fact that, along the

1 Note this,
104 STUDIES IN THE EVOLUTION OF ANIMALS

spine, and on the abdomen, the rosettes coalesce into solid blotches,
while on the flanks and shoulders they do not. This fusion and
dispersion are evidently under the control of the nerve-centres,
where modifications originate, and are only made appreciable by
modified markings on the skin.

But, really, why the rosettes remain as rosettes on the flanks,
and why they are dispersed on the shoulders of the Jaguar, while
they coalesce and form solid blotches along the spine and other
parts, ] am unable to make out.

Prof. H. B. Orr? says: ‘Any single nervous reaction, in a
connected and often repeated series, does not disappear the instant
its original stimulus is withdrawn. It will last for some time after-
wards under the influence of association with the rest of the series.
Eventually, however, it must disappear, sooner or later, according
to the firmness of the association.’

In the Jaguar and Leopard it would appear that the nervous
action is very date in disappearing, although they have been running
on parallel lines with Lions and Pumas for thousands, and, may be,
millions of years. They afford us an example of the persdstence
of influence, although the stimulus may have been withdrawn ages
ago, while in Lions, Pumas, and others the markings have almost
wholly disappeared.

It has been stated? that, at the Marine Laboratory of Plymouth,
experiments on the under surface of flat fishes have been made by
means of mirrors reflecting light from below. The under surface of
the fish first became spotted, then the spots amalgamated, and
finally the entire under-surface became dark. Photographs of
the different stages have been taken.

According to Prof. Lodge, light is electricity, and experiments

1 A Theory of Development and Heredity, p. 199.
2 Chambers’s Journal for August 26th, 1893, p. 541.
MEANING OF JAGUAR AND LEOPARD ROSETTES 105

may yet teach us a great deal about animal coloration and mark-
ings. The markings of the Jaguar, however, I think are due, not to
the action of light,‘but to a totally different cause, as I hope to show.

Mr. Poulton! considers it proved that the white hair of certain
Arctic animals is caused by the low temperature of the winter.
Quoting from Mr. Welch, he says that in the American Hare, on
the approach of winter, the dark hairs of the old coat turn white,
commencing either at the tip, the middle, or the base of the hair,
and that in addition there is a new winter coat coming up of an
entirely white colour. And at p. 103, Mr. Poulton says that the
young of the Arctic Hare are born grey, and turn white at their
first winter.

All this does not affect the fact that in dappled grey Horses the
spots are white, in: dappled brown and dun Horses the spots are
lighter than the ground colour, in roans they are black, and in
strawberry roans they are bay or brown. Moreover, I have seen a
grey Horse with tan-coloured spots.? So with many other animals
that might be quoted. It is clear that in these cases temperature
can have nothing to do with the difference in coloration, and we
have to search for other causes to account for the coloration of
certain animals, and more especially for those extraordinary mark-
ings we see in the Jaguar, the Leopard, the Cheetah, the Tiger, the
Zebra, and so many other mammals.

A study of the rosettes in Fig. 59, and many others that can be
seen on skins, makes it evident to me that, whatever may be the
initial atomic nervous influence which produces these variations,
they result in two sets of modifications, (a) a fuszon of some or of
all the encircling spots, and often in an obliteration of the enclosed
space; or (0) a dissociation of the encircling spots, and perhaps
even a scattering of the enclosed specks.

1 Colours of Animals, p. 95. 2 See Appendix C.
106 STUDIES IN THE EVOLUTION OF ANIMALS

Between these two extremes, numerous intermediate variations
of the rosettes occur, as the reader can see for himself.

I particularly dwell on the markings of the Jaguar, because they
appear to me to be the typical markings, out of which many others
we see in various animals have been elaborated or evolved.

It would be idle to suppose that each separate group of spotlets,
forming a rosette, was made as it is by a process of natural
selection. Such a notion would be wholly untenable. All the
rosettes have a family resemblance, and therefore must have had a
common origin. Natural selection may have had something to do
with maintaining the general character of the spotted skin, but it
could not possibly have had anything to do with moulding the
outlines of each individual group of spotlets.

We must therefore look for a cause or causes of these markings
which, at the same time that they allowed them to vary, stamped
them with the features of a common parentage. If the Leopards
have retained (not acquired) their very peculiar markings, so
different from those of the generality of mammals, it would seem
to follow that these animals emerged out of some more ancient
mould with these peculiar marks. Their common family resem-
blance would point to their being modifications of a still older
form of rosette, viz. that shown in No. 31, Fig. 59. How then did
this more ancient form of rosette originate ?—by natural selection
or what?

Before I attempt to reply to this question in my own way, I
would like to show how others have looked at it.

Dr. Wallace, in Darwinism, p. 288, says that Mr. Tylor! called
attention to an important principle which underlies the various
patterns or ornamental markings of animals, viz., that diversified
coloration follows the chief lines of structure, and changes at

1 Coloration in Animals and Plants.
MEANING OF JAGUAR AND LEOPARD ROSETTES 107

points, such as the joints, where function changes. Mr. Tylor
says: ‘If we take highly decorated species—that is, marked by
alternate dark or light bands or spots, such as the Zebra, some
Deer, or the carnivora, we find, first, that the region of the spinal
column is marked by a dark stripe ;1 secondly, that the regions
of the appendages or limbs are differently marked ; thirdly, that
the flanks are striped or spotted, along or between the regions of
the lines of the ribs ;? fourthly, that the shoulder and hip regions
are marked by curved lines; fifthly, that the pattern and the
direction of the lines or spots change at the head, neck, and every
joint of the limbs; and lastly, that the tips of the ears, nose, tail
and feet, and the eye, are emphasised in colour. In spotted
animals the greatest length of the spot is generally in the direction
of the largest development of the skeleton.’

Then at p. 280, still quoting from Coloration in Animals and
Plants, Dr. Wallace says that ‘Mr. Tylor was of opinion that the
primitive form of ornamentation consisted of spots, the confluence
of these in certain directions forming lines or bands; and these
again sometimes coalescing into blotches, or into more or less
uniform tints covering a large portion of the surface of the body.
The young Lion and Tiger are both spotted ; and in the Java Hog
(Sus vittatus) very young animals are banded, but have spots over
the shoulders and thighs. These spots run into stripes as the
animal grows older ; then the stripes expand, and at last, meeting
together, the adult animal becomes of a uniform brown colour.’

And on p. 290, Dr. Wallace says: ‘So many of the species of
Deer are spotted, when young, that Darwin concludes the ancestral
form from which all Deer are derived must have been spotted.

1 Sometimes it is zz¢e, as in certain Antelopes, and also in the Kerry breed of cattle.
° Undoubtedly the markings often cross the ribs, as in the Ocelots and the Viverride,
the Paca, etc.
108 STUDIES IN THE EVOLUTION OF ANIMALS

Pigs and Tapirs are banded when young; an imported young
specimen of Zapirus Baird? was covered with white spots in longi-
tudinal rows, here and there forming short stripes. Even the Horse,
which Darwin supposes to be descended from a striped animal, is
often spotted, as in the dappled Horses; and a great number show
a tendency to spottiness, especially on the haunches.’

Ocelli may also be developed from spots or from bars, as
pointed out by Mr. Darwin.

On p. 290, Dr. Wallace also mentions that in certain diseases
the pigment is destroyed along the course of a nerve and its
branches.

In this connection Mr, Darwin says:1 ‘Three accounts have
been published in Eastern Prussia, of white and white-spotted
Horses being greatly injured by eating mildewed and honeydewed
vetches, every spot of skin bearing white hairs becoming inflamed
and gangrenous.’

Other similar cases are quoted in other animals.

‘We thus see that not only do those parts of the skin which
bear white hair differ in a remarkable manner from those bearing
hair of any other colour, but that some great constitutional difference
must be correlated with the colour of the hair; for in the above
mentioned cases, vegetable poisons caused fever, swelling of the
head, as well as other symptoms, and even death, to all the white
or white-spotted animals,’

Some great constitutional difference must be correlated with the
colour of the hair. Undoubtedly ; and the starting-point would seem
to be the electricity of the nerve-centre cells, corresponding to the
white parts of the skin, acted on electrically by the poison in the
blood circulating among those central cells.

No one who has thought on this subject can doubt that the

1 Animals and Plants under Domestication, vol. ii. p. 331, second edition.
MEANING OF JAGUAR AND LEOPARD ROSETTES 109

action of the nervous system influences the pigmentation of the
skin, and the distribution of the pigments; but the nerves them-
selves seem to act only as conductors of the changes and influences
which lie deeper in the cells of the nerve-centres. In electro-plating
the wires conduct the influence of the action in the battery, and
the metal is separated from the solution, and is deposited on
the plate, or is dissolved off again, and returned to the solution
according to circumstances. So in the pigmentation of the
skin, the influence of the nerve-centres, acting through the
nerves, puts on or takes off pigment, and modifies it according to
circumstances.

Now the action of the nerve-centres depends on the blood, and
the blood depends on food and physical surroundings. But in
addition to all these, Aeredity undoubtedly plays a great part in all
these phenomena. And in order to answer the question I put, we
have to go back to features of still more ancient animals, which are
now wholly extinct, viz, of that large class of animals which
carried arnour plates on their skin, as part of what is called an
exoskeleton.

In remote times there were numerous animals protected by
plate-armour ; some of these have continued as survivals up to our
time—such as Armadillos, Turtles, Crocodiles, Sturgeons, and many
other curious fishes. Indeed, if we go lower down in the scale of
life, we find that the exoskeleton is the only solid part of the
animal structure, such as we see it in Crabs, Lobsters, and other
Arthropoda.

Among armour-plated animals, now extinct, were several known
species of Glyptodonts, like that shown in Fig. 60, the fossil original
of which is in the Natural History Museum.

The armour of these strange animals consisted of either circular
or many-sided plates, encircled by a rim of smaller polygonal
‘12H pue uewdeyy ‘sissay] jo uorssimad pury Aq !yopoidéty y—"og ‘oT

a

 

 

 

 

 

 

 
MEANING OF JAGUAR AND LEOPARD ROSETTES 111

platelets, like those of Fig. 61 (a), (4), (¢), (g). The form of these
bone-rosettes varied not only in different species, but also in the
same individual.

In the Natural History Museum, besides the Great Glyptodon,
there are fragments of the carapaces of other species, as shown in
Fig. 62.

 

&
@ Ox oa
f EVV vs 0 9
ag: Se NGO

 

Fic. 61.—Bone-rosettes of various Glyptodonts (reduced) : (2) from carapace of Glypotodon
asper; (6) from front, and (c) from back of head-shield of ditto (Natural History Museum) ;
(d) from G. Clavipes; (e) from G. ornatus; (f, g and h) from other Glyptodonts in the Royal
College of Surgeons ; (2) groups of tail plates of a Glyptodont (Natural History Museum).

Then in the museum of the Royal College of Surgeons there
are remains of other forms of Glyptodonts, with bone-rosettes
which perhaps are still more suggestive. In Fig. 61 (a), (e), (/),
(g), (2), some of these rosettes are shown.

As these bone-rosettes? are taken from fossil remains, the
edges of the component plates, and in some cases their surfaces,

1In the Natural History Museym, the plates of the Carapace of the Glyptodon and
Armadillo are called ‘ ossification of the derm.’
112 STUDIES IN THE EVOLUTION OF ANIMALS

may have become partially eroded. Indeed, in some fragments,
the platelets are almost wholly defaced, as shown in Fig. 62 (4).
But I think that any unprejudiced evolutionist will not fail to see

 

Fic. 62.—Bone-rosettes from other species: (a) from carapace of Hoplophorus; (6) from
carapace of A. Megerz ; (c) from fragment of a Hoplophorus (Natural History Museum).

in them the ‘blocks,’ so to speak, from which the Jaguar got tts
zmprints |

Moreover, on the pelvic shield of Polacanthus Foxit, Fig. 63
(a), the remains of a Stegosaur in the Natural History Museum,
and on the tail armour of a Hoplophorus, (6) we find armour-plates
MEANING OF JAGUAR AND LEOPARD ROSETTES 113

like those on Fig, 61 (g), which assimilate better perhaps with
the typical Jaguar rosette shown in No, 31, Fig. 59.
Here I would note that the lumbar shield of Tolypeutes tricincta,

; C 4
age ; 000 9
0. be 2.
iw Be Bey (3 oO

Fic. 63.—(az) Armour-plates of Polacanthus Foxii (Stegosauria) (reduced) ; (4) plates from
the tail of a Hoplophorus (one-third natural size) from Fig. 1164, Nicholson & Lydekker's
Paleontology, vol. ii. ; (c) plate from Tolypeutes tricincta ; (d) plate from Priodontes Peba.

an existing Armadillo, is composed of plates like those of Fig. 63
(c), and those of the Peba Armadillo (Priodontes Peba) are like
those of (@) of the same figure, both which assimilate with the

Fic. 64.--(a) Plates from shoulder and lumbar shields of Ta¢wséa Peba, the seven-banded
Armadillo; (4) plates from the Great Armadillo, Priodontes maximus,—(Natural History

 

 

Museum. )

Of course in some of the modern Armadillos the shield plates
are much altered, but anybody can see that they consist of the
same elements as shown in Fig. 64 (a). In (4) they are still more

H
114 STUDIES IN THE EVOLUTION OF ANIMALS

altered, and not impossibly the rim of each plate in this case is a
fusion of the ring of platelets of others.

In Elliot’s monograph of the Fedde I met with a very curious
assimilation between the disposition of plates on the forehead
shield of an Armadillo, and the disposition of the coloration on the
forehead of a domestic Cat. The latter forcibly recalls the former.
Both are shown in the accompanying Fig. 65.

I have seen this forehead mark in other domestic Cats. Those
specks which we see on the Jaguar skin, enclosed within the ring of

 

Fic. 65.—(a) Mark on the forehead of a domestic Cat (Elliot’s Feé¢d@); the centre is
brown, edged with black, and surrounded by a light ground; (4) forehead shield of an
Armadillo, shown under the paw of /. Yaguarundi (Elliot’s Feléde).

spotlets, such as those of Nos. 26 to.28, Fig. 59, may just be the
modified imprints of the little knobs we see on the hexagonal
plates of Tolypeutes, a kind of Armadillo (Fig. 66(@)). But recently
Mr. Lydekker has possibly imparted to these inner specks a speczal
interest. In No. 101, new series, of Knowledge, March 1894, Mr.
Lydekker has described the club-tailed Glyptodont of Argentina.
Each plate of this animal’s carapace has several fo/es in it, which
the writer supposes gave passage to spines. Whatever they may
have given passage to, it strikes me very forcibly that the specks
in the interior of the Jaguar rosettes, or imprints, as I would call
them, of ancestral carapacial plates, may possibly be the imprints

1 T have seen rosettes on a Jaguar (Tring Museum) with as many as séx specks.
MEANING OF JAGUAR AND LEOPARD ROSETTES 115

of holes szmzlar to those on the plates of this curious Dedicurus,
now in the La Plata Museum!

In past ages there were numerous carapaced animals even as
low down as the fishes. Although I have been stating that the
Jaguar and other Cats probably descended from Glyptodontoid
ancestors, I do not mean that a// the Cats descended from the same
pair of ancestors, for it is obvious that some may have descended
from one species, and others from others. Afterwards they may
have intercrossed, just as they are able to do now. For instance,
in the Cheetah, the marks are different from those of the Jaguar,

a

 

Fic. 66.—(a) and (2) are from Ostracions in the York Museum ; (c) from another Ostracion,
an armoured fish ; (d) from pelvic shield of a Tolypeutes, an Armadillo (from Fig. 1161, vol. ii.
of Nicholson and Lydekker’s Paleontology).

and in the Horse we see transitions of marks which are like stars.
Here are some patterns of plate armour for the reader to choose
from (Fig. 66).

It may be asked, If other spotted animals have so much altered,
why has not the Jaguar? Well, somewhat similar questions are
often asked by women—‘If we came from Monkeys, why do not
Monkeys zow turn into men and women?!’ The answer is obvious
to the mind of an evolutionist. The ancestral form, like every
living thing, must either live or die. If it have endurance in its
constitution, and is also suited to its surroundings, it will endure
side by side with the variations which originated from it, In some
116 STUDIES IN THE EVOLUTION OF ANIMALS

cases it may endure Jeéter, and the variations may become extinct ;
while in other cases, the variations may endure better, and the
parent form may become extinct.

Thus we see Monkeys themselves varied in a hundred ways,
enduring side by side with man, who possibly originated from the
Monkey-plane, and they may continue to endure until perhaps they
become his rivals, and competitors for the consumption of his crops.

Professor Parker! says: ‘Why such a form as the Glyptodon
should have failed to keep his ground is a great mystery ; nature
seems to have built him, as Rome was built, for eternity. His
exquisite little relative, the Ch/lamydophorus, scarcely larger than a
Mole, has continued as yet to run out of danger, safe in his little-
ness ; and many other kinds of low-brained mammals have, so to
speak, the power to make themselves practically invisible.’

In another place I have ventured on a speculation which may
account for the descendants of the Glyptodonts losing their carapace.

All these armour-plates of existing and extinct animals are
most suggestive,and I consider them very important elements in
the interpretation of the rosetting of the Jaguar.

After the armoured animals lost their skin-stiffening of lime
deposit,the imprints of armour-plating must have become vastly more
subject to modification than before, and so we have the endless
forms of spotting and marking in mammals. After millions of
generations that have been born since the Glyptodonts, and other
Armadilloid animals, lost their bone-plates, it cannot be expected
that the skin should retain the original outlines of plates un-
changed. The great wonder is that the Jaguar has retained the
features of its ancestral bone-plates zw7th so little modification |

As an instance of the slowness, under favourable circumstances,
with which long established characters are got rid of, both from the

1 Mammalian Descent, p. 94.
MEANING OF JAGUAR AND LEOPARD ROSETTES 117

body and from its ruler the brain, the rosettes of the Leopards may
be quoted. Who can tell how many millions of generations have
elapsed since the ancestors of these animals and their congeners
threw off their calcareous carapace, and adopted a masquerade of
pigment-rosettes instead? Yet to this day this masquerading goes
on in the Leopards and Jaguars, in their black varieties, as well as
in the Snow Leopard. They are unable to shake off this pigment
dress inherited from a calcareous carapace, although their habits
and customs, their entire skeleton and teeth, have undergone great
modifications.

2 é

 

Fic. 67.—Bone-rosettes from the carapace of the Glyptodon, Natural History Museum,
(a) partially fused rosettes from front of carapace, (4) distinct rosettes from side of carapace.

It must not be supposed, however, that bone-rosettes are not
subject to fusion and other modifications. Fig. 67 (a) shows two
bone-rosettes with a tendency to approximate and partially fuse ;
while (6) shows them quite distinct, and are given for comparison.

Hitherto I have traced the similarity of the Jaguar rosettes with
the bone-rosettes of Glyptodontoid and Armadilloid animals which
are also mammals. But chz cerca trova! Strange to say, this
similarity can be traced much further down in the scale of life,
and therefore much further back in time. Among the Chelonians
we seem to find the identical mould from which the Glyptodon
derived its bone-rosettes.

The Leathery Turtle (Dermochelys coriacea) has thin mosaically
118 STUDIES IN THE EVOLUTION OF ANIMALS

disposed plates on its carapace which at first sight seem a con-
fusion of platelets without any order; but further investigation
reveals on the right side, below one of the longitudinal crests,
the fact that several of them are disposed in distinct rosettes

rh
Cale |
3 “yn \ ee 7 .

 

Fic. 68.—(az) Bone-rosettes on the carapace of the Leathery Turtle (Dermochelys coriacea) ;
(4) crested pate of Nile Crocodile, encircled by small plates from right flank ; (c) crested plate
of Sturgeon (Accipenser sturio) seen between the larger plates on the spine and flank; all
from the Natural History Museum.

exactly like those of the Glyptodon, as shown in Fig. 68 (a).
Curiously enough, this Turtle is one of those whose carapace is mo¢
like that of other Turtles, fused with the spine and ribs. There is
therefore some suspicion that it may be one of the ancestral forms
of such mammals as the Glyptodonts, otherwise it would be strange

1 Specimen in Natural History Museum.
MEANING OF JAGUAR AND LEOPARD ROSETTES 119

that the Leathery Turtle should exhibit the identical bone-rosettes
of the Glyptodon. They are no doubt very much thinner, as if
they may be either forming or disappearing ; nevertheless, no one
can doubt that they are the same things, and are produced by the
same cause, whatever that may be. It is also noteworthy that
two of the Turtle rosettes show a tendency to approximation and
partial fusion, like those of Fig. 67. This community of features
points to the probability of the Glyptodonts having emerged from
some Turtle-like water-animal.

J c
DP. pe Zz
%OdG °
2% Se 290°
o 90 § Sag
Qe
Soo? 220.9
oad)
ora oP
SSusO5
Wo . Su9

2

  

Fic. 69.—(a) Group of ornament tubercles on head-shield of Axcephalaspis Paget (Prof.
E. R. Lankester's Monograph of the Fishes of the Old Red Sandstone of Britain, p. 49). ‘The
scales have the same character of markings; (4) ornament in polygonal plates tuberculated of
Hlemicyclaspis Murchisoni, p. 52; (c) Portion of test or shell of Achinus gracilis (Zoology of
the Invertebrata, by A. E. Shipley p. 241).

Then the Nile Crocodile and the Sturgeon show in their armour
forms of plating similar to the imprints of the Jaguar, as seen in
Fig. 68 (4) and (c).

Lower and lower still in the scale of life we meet with the same
curious pattern in its more primitive form, viz., that ofa central larger
plate surrounded by a ring of smaller plates or tubercles. I would
not venture to suggest that the spotting of the Cheetah has any
relationship with the plates on the test of the Echinus, or with those
of armoured fishes ; for, if I did, I might be laughed at, and there-
fore I simply give the markings on these animals in Fig. 69 so that
the reader may judge for himself.
120 STUDIES IN THE EVOLUTION OF ANIMALS

(2) Shows the ornamentation on the head-shields of Encephalaspis
Paget, an extinct Sturgeon-like fish ; (6) shows a plate from Hemz-
cyclaspis Murchisoni, an extinct animal like an Armadillo; while
(c) are from the test of an Echinus.

Then, curiously enough, the Pearly Nautilus in the Natural
History Museum, on its soft hood exhibits a similar pattern, al-
though it does not seem to have there any calcareous deposit. The
soft hood appears to act as an operculum when the cephalopod
withdraws into its chamber, and therefore may at one time have
been armoured,

It would seem preposterous to endeavour to carry on the
relationship of the Jaguar and Cheetah markings to those on the
armour of the Cephalaspide,! or the Echini. Yet if we are evolu-
tionists, and if creation by the method of evolution be true, the
Echinus and other low forms cannot be left out in the cold because
such hints as I have made would outrage our feelings! We must
look upon the markings of certain fishes and of the Echini as
connected somehow with those of the higher land animals.

Evolutionists go even further than this, and admit that all
animal forms on the earth were evolved from the minute pelagic
forms, many of which are still in existence. The doctrine of
evolution would teach us that all these phenomena are rather a
matter of course than mere unexplainable anomalies.

It does not, I think, require much acumen to see a family
resemblance between the figures of the Glyptodon’s bone-rosettes
and the spot-rosettes on the flanks of the Jaguar. Indeed, a glance
at the back and flanks of Fig. 4 will readily suggest the impression
of a carapace composed of plates not dissimilar to those of the
Glyptodon. I do not say that the Jaguar descended from a Glypto-
don, but I do say that this mammal descended from some extinct

1 The Cephalaspide were Sturgeon-like ancient extinct fishes.
MEANING OF JAGUAR AND LEOPARD ROSETTES 121

animal with a Glyptodonfozd carapace. I repeat that the bone-
plate rosettes on Figs. 61 and 62 speak to us only too plainly.
These armour-plates of extinct animals are to my mind the ‘ blocks’
which gave the Jaguar skin the impressions of the groups of spots
or rosettes, much modified in subsequent innumerable generations.
In other words, the skin, on losing its hard calcareous plates, retained
somehow an impression of them, which modified the pigmentation,
where the plates in its ancestors originally stood. Or again, to put it
more ‘nervously, the action of the nerve-centres which caused the
deposition of calcareous matter in rosette-form, on the skin of the
Glyptodonts, continued to act when there was an zusufficient amount
of calcareous matter in the blood for this purpose That is, in the
nerve-centres a sort of memory of former plates remained, which
expressed itself in pigments after the calcareous carapace had gone.
This nervous action then resulted in the deposition of pigments of
colours different from those of the general skin. In many mammals
this nervous action dwindled into the deposition of simple spots ;
in others it fused them into lines and patches, and in some they
were entirely obliterated, as in the adult Puma and others.

The intervals between the Jaguar and Leopard rosettes—now
altered, as I said, through innumerable generations—would seem to
indicate the sutures between the armour-plate rosettes of some
ancestral Glyptodontoid animal.

 

Of course the skin of the Jaguar is elastic and mobile, and
stretches readily to adapt itself to the growing animal and to the
different variations in size which we see in the Cat tribe. Its elas-
ticity would seem sufficient to account for the droadening of the
network of sutures which we see everywhere between the Jaguar
rosettes, and perhaps also for the dissociation of the spotlets which

1 In the Natural History Museum there is an interesting series of skins of Lacertilia ;
some have fully ossified scales, others have only vestzges of ossification.
122 STUDIES IN THE EVOLUTION OF ANIMALS

compose the groups on its shoulders (Fig. 4); and not improbably
the stretching of the skin might partially account for the charac-
teristic spotting on the haunch of the Cheetah shown in Fig. 59,
Nos. 33-35.

In Fig. 70 (a) I have endeavoured to restore some of the plates of
the carapace of the Jaguar’s immediate ancestor. Of course this
restoration is imaginary, but it is suggested by five contiguous
rosettes on the Jaguar's left flank, behind the shoulder (Fig. 4). I

 

Fic. 70o.—(a) Restoration of the rosettes of an imaginary Glyptodontoid ancestor of the
Jaguar, with closely interlocking plates ; (4) The same in subsequent forms of mammals,
when the plates may have become dissociated, with intervening flexible skin.

have shown the plate-rosettes as closely fitting in (2); but imagine
them to have become somehow dissociated as in (4), from causes
which I have already discussed, and you have intervening channels
or commissures of flexible skin, such as we see in the Crocodiles,
and also between the bands of the Armadillos. These skin com-
missures are now represented in the Jaguar by the paler ground
colour reticulated between the rosettes. I have given the imagined
plates a trapezoid shape, to make them similar to the Jaguar rosettes,
but the shape of the latter may have become much distorted, as
indeed we see it in various parts of the Jaguar skin itself. I have
MEANING OF JAGUAR AND LEOPARD ROSETTES 123

also given five little specks on each central plate, to assimilate them
with some of the Jaguar rosettes, but there may have been many
more, as in the plates of Tolypeutes.

All this imaginary restoration, however, was hardly necessary,
as in Fig. 62 (c), which is part of the carapace of a Glyptodont,
shows an almost zdentical arrangement of bone-rosettes.

Reference to Figs. 61 and 62 will show how various the
number of small plates is which encircle the bigger central plate.
In some cases the inference would be that the smaller plates have
occurred to completely fill in vacant spaces left by the larger and
more solid plates, and thus leave no part of the skin unprotected.
Where great flexibility is needed, as between the bands of Arma-
dillos, it is obvious that plates would be an encumbrance, and simple
elastic skin preferable.

The dissociation of the plate-rosettes, with intervening elastic
skin, would have admitted of freer movements—a feature of great
importance in the struggle for existence—than would have been
possible in the dish-cover solid carapace of a Glyptodont.

This dissociation of plate-rosettes is not simply a hypothesis, for
we see it actually occurring on the abdomen of the Great Armadillo
(Priodontes maximus), which in that region has rows of separate
rosettes, composed of minute plates, while the carapace is formed
of bands of squarish plates, with intermediate skin commissures,
like those shown in Fig. 64 (@).

It may perhaps be objected, that if the plate-rosettes could be
dissociated bodily, the component smaller plates could also be dis-
sociated. Just so, and that is what may have occurred in the ances-
try from which the Cheetah has descended. Its plate-impressions,
large and small, though probably much modified, are scattered all
over its skin.

1 Edinburgh Museum of Science and Art.
124 STUDIES IN THE EVOLUTION OF ANIMALS

In snakes we see closely fitting scales, but in the Python, and
in the expanded hood of the Cobra, the scales are scattered over
the skin, with intervening spaces wéthout scales. So that stretch-
ing of the skin may have had something to do with the scattering
of the rosettes, whether as
dissociated bone-plates or
dissociated pigment-spots.

There is another feature
in the Leopards which is
worthy of notice. On their
legs there are transverse
rows of small spots. These, in my view, are impressions left by
transverse rows of small plates, not unlike those which we see on
the legs of an existing Armadillo, shown in Fig. 71.

 

Fic. 71.—The Hairy Armadillo (Dasypus vil-
fosus), Natural History Museum.

We now begin to get a sort of ‘moral conviction’ that the
transverse stripes on the legs of Tigers, and other Cats, are due to
ancestral rows of spots like those on the legs of Leopards, and these
in turn are due to the fact that their armoured ancestors had scales
or plates there, szmzlarly disposed.

In the Hairy Armadillo and others no doubt the leg-plates are
in process of extinction. As the animals can roll themselves up in
their banded carapace, their leg-plates have become superfluous,
and are doomed to extinction,

Taking then everything into consideration, I think it will be
found difficult to escape from the conclusion that the markings of
the Leopards are zzherited from ancestral plate-impressions of some
extinct Glyptodontoid form, and have zo¢ been evolved by a process
of natural selection.

It is a wonder to me that in the Jaguar so much likeness to
ancestral bone-plates still remains as to enable us, through these
hieroglyphics, to read the story of its descent. But for these
MEANING OF JAGUAR AND LEOPARD ROSETTES 125

Jaguars and Leopards, the ever-recurring variations which we see in
living mammals would have prevented us from deciphering mark-
ings which are all but universal in mammals, but so strangely
altered ; for who would have conjectured that the stripes of the
Tiger had anything to do with an armour-plated ancestral carapace ?

The very fact of those great Armadillos having become extinct
may have resulted precisely from the unstretchable nature of their
bony skins. Their movements must have been hampered to a vast
degree ; and the great difference between their edentate jaws and
the jaws of the carnivora is enough to indicate to us the vast
changes that must have occurred from the days of the Glyptodonts
to those of the existing carnivora.

In another place I have shown that the markings of a large
number of carnivora are traceable to modifications of the markings
of the Jaguar. I have also shown that some Horses have rosettes
(Fig. 56 (@)) not very dissimilar to those imaginary ones of Fig. 70.
I take the dappling of Horses to mean a fusion of the ancestral
Horse rosettes ; and the Zebra banding again as a modification of
the ancestral dappling. Then the rosetting, spotting, and striping
of the ruminants would be further modifications of the original
Horse-like vosetting. In the ‘old Giraffe’ we seem to have a fusion
of a number of rosettes to form the polygonal blotches, with droad
commissures ; while in the ‘ new Giraffe’ of Somaliland, the poly-
gonal blotches are approximated and the commissures are not so
broad.

Further on I have endeavoured to show cause for the thinning,
disintegration, and the final disappearance of such massive cal-
careous carapaces like those of the huge extinct Glyptodonts from
which all this picture rosetting, spotting, blotching, striping, and
banding in existing animals, as I think, have come.

After the exoskeleton was got rid of, the internal skeleton went
126 STUDIES IN THE EVOLUTION OF ANIMALS

on evolving zudependently of the coloration of the skin, and that
may be the reason why we find almost identical coloration or
markings in mammals, with vast modifications in their endo-
skeleton.

What were at one time solid plates with holes or knobs, became
later on expressed in simple pigments of different colours to the
great advantage of the losers of such a stiff and unmanageable
encumbrance.

If it be true that the rosetting of the Jaguar and Leopard origin-
ated as I have stated in the foregoing pages, the same theory will
account for the markings of Horses and other mammals, including
ruminants and more especially Oxen, as testified by the rosette
markings of the Zebu (Fig. 58).

POSTSCRIPT

Wuite this book was passing through the press, I read in Knowledge of
January 1895 a paper by Mr. R. Lydekker on the ‘Spots and Stripes in
Mammals,’ wherein he gives Professor Eimer’s and his own views of the
origin of mammal coloration, as he does not seem to agree with Pro-
fessor Eimer.

Iam sorry to disagree with two great authorities on these matters, but
Thomas Carlyle’s teaching was this—say what you ¢hzzk, even if you are
gibbeted for it.

I cannot make this subject intelligible to the reader without giving
extracts of some length from Mr. Lydekker’s paper ; and perhaps it will
be better if I take certain points of his paper one after the other, and try
to discuss them, as the questions are exceptionally interesting.

On p. 3 he says :—

‘These markings generally take the form either of longitudinal or trans-
verse bands or spots, the latter being frequently arranged in more or less
distinctly defined longitudinal lines, but * never” in transverse bands.’
POSTSCRIPT 127

I think I have shown that both in the Leopard and in the Horse spots
do not infrequently arrange themselves in fvansverse lines or series.

P. 4. ‘A similar state of things occurs among wild Pigs, and also in Tapirs,
from which we are naturally led to infer that in this group of mammals, at least,
a spotted or striped type of coloration is the “original” or generalised con-
dition, while a uniformly coloured coat is an acquired or specialised feature,
and we shall find that this will hold good for other groups.’

In my humble opinion—and I have tried to show why I hold this
opinion—both the s¢riped type of coloration and the uniformly coloured
coat are derived from the spotted or rosetted types.

In writing of the Rodents, Mr. Lydekker says (p. 4) :—

‘A survey of the collection of these animals in a good museum will show
that, whether the patterns take the form of stripes or spots, the arrangement is
invariably longitudinal, and “never” transverse.’

Now, it is impossible to separate the Rodents from other mammals, and,
as I have already said, transverse rows of spots and rosettes are not
uncommon in other mammals. All that we can infer is, that in the
existing Rodents no species with transverse stripes or spots are found.
Perhaps this is what Mr. Lydekker meant.

P. 4. ‘By a splitting-up of a simple spot into a more or less complete ring
of smaller ones, we have the rosette-like type of ornamentation, as exemplified
in the Leopard, the Snow Leopard, and the Jaguar. In the two former, the
ring encloses a uniform light area ; but in the latter the central area generally
carries one or more dark spots.’

I confess Iam unable to accept Mr. Lydekker’s view of the origin of the
rosette from a splitting-up of a simple spot, for reasons given in Part III.
T am indebted to Mr. Lydekker himself for a hint of the va/we of those
interesting ‘one or more dark spots’ in the central area of the Jaguar
rosette.

In one of the numbers of Axow/edge he described a strange Glyptodont
(Dedicurus), with a club tail, in the La Plata Museum. The oles in each
armour-plate of that singular animal are, in my opinion, the eguivalents of
the dark spots in the interior of the Jaguar rosettes, a remarkable example
of which is to be seen in the Tring Museum.
128 STUDIES IN THE EVOLUTION OF ANIMALS

Then, in the beautiful illustration of the Snow Leopard in Mr. Lydek-
ker’s paper under discussion, we seem to follow the genesis of the stripes
on the tail gradually from the rosettes on the haunch of the animal.
The rosettes are carried on to the base of the tail, and insensibly, by
flattening and obliteration of the enclosed area, they are converted into
stripes. So that we have the choice of wo modes of genesis of stripes—
either, as I have shown, from rows of rosettes, like the twin stripes of
certain Tiger skins, or from single rosettes, as indicated above.

P. 4. ‘A further development of the ring leads to the so-called clouded
type, as displayed by the Oriental Clouded Leopard, the Marbled Cat, and the
American Ocelot. Here the ring becomes enlarged into a large squarish or
oblong area, enclosing an area of darker hue than the general ground-colour
of the fur, and bordered by a narrow black line,’

In discussing the markings of the Ocelot, I have shown that their curious
markings result from a fuston of many rosettes disposed in longitudinal
order, and not from an ex/argement of ‘the ring.’ In the Ocelots it is a
longitudinal fusion of a number of rosettes; in the others it is a squarish
patch, formed, as I think, by the fusion of a group of rosettes into one
large island. Many modifications may have occurred after fusion, and in
the Clouded Leopard we have perhaps a transition from this into the
eventual uniformly coloured coat—a sort of breaking-up of the whole
patch.

The curious part is that in some Ocelots the central dark spots of the
rosettes are still retained, but they become arranged in line in the centre
of the longitudinal band, while the amalgamated rings form a black border
to the scolloped band.

P. 5. Professor Eimer, ‘as the result of his investigations, laid down the
following laws :—

‘Firstly, the primitive type of coloration took the form of longitudinal
stripes ; secondly, these stripes broke up into spots, retaining in many cases a
more or less distinct longitudinal arrangement; /¢hzrdly, the spots again
coalesced, but this time into transverse stripes. And, further, all markings
disappeared, so as to produce a uniform coloration of the coat.’

To this Mr. Lydekker says (p. 5) :—

‘There ought, if the theory were true in its entirety, to be a considerable
number of longitudinally striped species among the lowest groups of all...
POSTSCRIPT 129

Professor Eimer makes no distinction between light and dark markings ... .
nevertheless we may provisionally consider light and dark stripes and light
and dark spots as respectively equivalent to one another.’

I presume that by the ‘ lowest groups of all’ Mr. Lydekker means the mar-
supials, Biologists look upon these animals as the most primitive types of
mammals, and therefore the oldest. This, I should say, is a good reason
for believing that they had, compared with others, a far longer time to
change in, conformably with surroundings of sorts, and therefore it must
be a wonder that we meet with amy of them which are marked at all
with either spots, stripes, or bands. Nevertheless some of the marked
ones still survive !

This, in my humble opinion, is sufficient evidence that both they and
the other mammals of superior organisation came from the same marked
stock.

P. 5. ‘The fact that the markings of young Pigs take the form of longi-
tudinal stripes, whereas in the more specialised Deer, whether young or old,
they are in the shape of spots arranged in more or less well-defined lines, is,
as far as it goes, a confirmation of the theory that “spots” are newer than
stripes.’

My own studies of this interesting question have led me to just the
opposite conclusion—viz., that spots are older than stripes, and that
rosettes are the o/des¢ of all markings.

_ Perhaps too much stress has been laid on the word specialised.
Although the skeleton may be highly specialised, it does not appear to me
to follow that the exterior of the animal will march pari Zassu with its in-
terior. Indeed we know that it does not. For the young and the adult
of the Puma are both equally specialised, yet the former is spotted, while
the latter is plain. It seems to me that the exterior of a mammal would
be more actively influenced by its surroundings of sorts than its interior.
And so it happens that we find, among so many differently specialised
orders, survivals of ancient coloration, which occur 77 spzte of the special-
isation conformable with the order to which each may now belong.

With regard to the longitudinal stripe down the back, several views
seem to suggest themselves as to its origin: (@) It may be an extreme
contraction of a broadly dark back, such as that of some Squirrels; (4)
It may be a fusion of the oblong black spots which we see along the
spine of many Leopards. It may persist /onger, for some reason, along

IT
130 STUDIES IN THE EVOLUTION OF ANIMALS

the spine, when on the flanks, shoulders, and hind-quarters all markings
have disappeared. ‘The total obliteration of markings we begin to notice
on the hind quarters and legs of the Quagga. LElither the spinal line, or
the leg stripes, or both, seem to persist when the body becomes plain.
Why it should be so, if it is so, I do not know; (¢) I have tried to account
for this spinal dark line, as a picture-remnant of the dorsal ligament,
which, in the little Pichiciago, binds the horny carapace to the spinal
line.

This curious little Armadilloid mammal seems to be a survival of a
transition stage between the bony-carapaced Glyptodonts and the hairy
mammals, the former, as I think, having been the fathers and mothers,
not only of carapaced mammals, but also of a// hairy mammals; and I
take it the Jaguar presents us- with good evidence of all this.

But after all this dorsal line may perhaps be of little importance ; for
any one can see, in the Tiger skins of the furriers’ shops, that, in certain
specimens, some of the transverse stripes merely meet at the spine, while
others, after meeting, are conjointly Aro/onged in the direction of the tail.
What is curious is this: that, in some mammals, this dorsal line is white.

P, 5. ‘Then again, in the ungulates we have the Zebra-Antelope, the
Gnus, and the Zebras showing most strongly-marked transverse dark stripes ;
but we have no dark-spotted forms in the whole order except-the Giraffes ;
while the only ones with dark longitudinal stripes are young Pigs. And it
would-thus appear that, although all the animals above mentioned are highly
specialised species, these transverse stripes and dark blotches must have
originated de zovo quite independently of the groups in question.’

I must humbly beg to differ from all this. I have shown that Horses
do not unfrequently have dark spots—even one little Donkey had them
—and that, in the grey-dappled Horse, the white spots are sometimes
arranged in transverse series of lines. These, by fusion, would give an
alternation of white and dark stripes. The blotches of the Giraffe assimilate
with the blotches of the Horse. Then the rosettes of the Zebu of this
work are almost ¢dentica/ with those of certain dappled Horses.

As the coloration both of the Giraffe and the Zebra harmonises with
their surroundings, Mr. Lydekker thinks—p. 6, that,

‘It is incredible that both types should have been evolved, according to a
rigid rule from animals marked by dark longitudinal stripes,’
POSTSCRIPT ke 131

That, is from the primitive markings of Professor Eimet’s theory. Quite go,:
but, as I have shown, it is not so incredible that both the coloration of
the Giraffe and of the Zebra, as well as those of the dappled Horse and
of the Zebu, should have been evolved. from, in my opinion, the oldest
coloration of all, viz., the vosefées, similar to those of the Jaguar. +

Mr. Lydekleat -in conclusion says that.it is not improbable that there.
may be a certain substratum of truth'in Professor Eimer’s theory.

‘What we may reall the “longitudinal- -spotted- transverse-uniform ” theory of
coloration, we submit that in its present guise it cannot adequately explain the
whole evolution of “spots and stripes in mammals.”?

Mr. Lydekker’s paper on this subject in Anow/dedyge is very well worth:
the attention of students of the coloration of mammals. It is, moreover,:
accompanied by the most Desuhiy! illustration ‘of the Snow:Leopard that
I have -yet seen.

..Now,. may I be allowed to. put. forth in concluding this P.S. my
theory:.of the whole question; as succinctly as I.can—as Carlyle might
have said,—the theory of.a poor ‘simple creature ? % a

The. Glyptodonts, or other armoured mammals of a ctl nature,
were the originals from which all existing mammals, including marsupials,
descended. oc

The Jaguar, for some reason or other, has retained the most primitive
type of coloration, due to the characters of the ancestral armour-p/ates—
a sort of Aicturation of the carapace, after this had been wholly got rid of.

- All other ‘spotted: mammals—whether longitudinally, or transversely,
or. diagonally-Lare modifications of those of the Jaguar..

Then the stripes—whether longitudinal, transverse, or diagonal—are
fusions of lines of spots or of rosettes. This seems clearfrom the spotting
of certain Cheetahs, certain Horses, and certain Tigers with twin-stripes.

The markings of the Ocelots, Clouded Leopards, and Marbled Cats
are a fusion and modification of groups of rosettes, either longitudinally
disposed, or grouped in irregular-patches.

‘The::piebalding of the Dog’’seems to be made up of fusions and
aggloniterations of spots, as maybe seen in certain Dalmatian and other
Dogs.

Then in the’ self-coloured ainsi it is evident there is, ict some
reason, a total obliteration of all special marking, although they now and
132 STUDIES IN THE EVOLUTION OF ANIMALS

again turn up as atavic marks, perhaps by some atomic disturbance of
crossing in the nerve-centres.

The curious point is, that white, black, and tan colours are zzterchangeable
—why, I donot know. This can be readily seen in the Fox-Terrier. The
black patches of the one are almost identical with the tan patches of the
next, The black and tan colours of the one become tan and white
colours of the next, and so on. Evén the tan spots over the eyes have
been known to change into white spots. So that it is no wonder that we
see black spots or stripes in one order of mammals changing into modified
white spots, or modified white stripes, in another order of mammals.

The interchangeableness of these three colours, with variations in the
shades of the tan, can be seen in many other mammals, both domesticated
and wild.

Lastly, when all vestiges of rosetting, spotting, or striping have dis-
appeared, as in self-coloured mammals, there may remain a vestige of the
ancestral carapace as a whole, without any vestige of the separate plates.
This I take to be the meaning of the dar colour of the dorsal and flank
regions, as contrasted with the abdominal coloration, which I take to be a
vestige of the ancestral uxarmoured surface. The contrasted colours may
be black, tan, brown or white (brown being a combination of tan and
black).

That curious flank band which some mammals have, clearly seen in
certain Squirrels, may possibly be a vestige of the receding carapace in
process of total obliteration, and the different contrasted colours may in-
dicate the different ages of partially unarmoured surfaces—that is, the
abdominal colour would indicate the oldest unarmoured surface, the
flank band a later unarmoured surface, and the dorsal colour the latest of
all; The origin of this flank band is, however, not so clear to my mind
as the other parts of this theory. I think we will find it impossible to
account for every line, or band, or spot in the coloration of mammals,
because the modifications in their coloration have been very great.

' We cannot call the whole self-coloration as the youngest of all, for
there may have been selfs among marsupials very much earlier than
among other orders. Each group of mammals should, | think, be studied
by itself, with an eye to its descent from some sort of carapaced ancestor.

It is a marvel to me that so much has been left to us of these hiero-
glyphics in which ancestral characters had been written, and that they
POSTSCRIPT 133

have been so stamped in the nerve-centres that even time has not
succeeded in wholly defacing them !

It is a marvel to me also that marsupials, being the oldest mammals,
have anything left on their exterior to give any indication of their descent
from, as I think, the common stock of avmouved mammals !

Of this there cannot be much doubt. Armoured vertebrates—Fishes,
Saurians, Chelonians, Glyptodonts, etc., formed, at one time of the earth’s
history, a vast portion of its inhabitants.

In the Royal Natural History, vol. iii. p. 64, indication is given of
the existence in former times of some sort of armoured Dolphins. Under
extinct Cetacean-like animals—Zeuglodonts, it says, ‘So far as they can be
determined, the general characters of these Zeuglodonts are such as we
should expect to find in an ancestral group of Cetaceans; but it is
remarkable that the body appears to have been protected by an armour of
bony plates,’ (!)
FURTHER EVIDENCE IN SUPPORT OF THE
THEORY THAT EXISTING MAMMALS
DESCENDED FROM CARAPACED
ANCESTORS
‘Nothing impresses the stamp of truth upon an hypothesis more than the fact that its
light renders intelligible not only those facts for the explanation of which it has been
framed, but also other and more distantly related groups of phenomena.’

‘ -< Professor WEISMANN, Ox Heredity, p. 336.
PART IV

FURTHER EVIDENCE IN SUPPORT OF THE THEORY THAT
EXISTING MAMMALS DESCENDED FROM CARAPACED
ANCESTORS

THERE is yet another important feature in the coloration of animals
which, if I have rightly interpreted it, will further support the
theory I have been advocating in the foregoing pages—viz., that
the markings of Leopards, Horses, Zebus, Giraffes, etc., etc., are
due to the plate-armour of remote ancestors.

In these pages, however, I shall deal with mammals which may
have no vestige of ancestral rosetting, but only a great contrast of
surface coloration.

It has been maintained by some that the backs of certain
animals are darker than their abdominal surfaces, because their
backs are more exposed to light.

I do not know whether this is true of all fishes. Recent experi-
ments would tend to show that light, as an electric agent, has some-
thing: to do with the darkening of the skin of fishes.

I do know, however, that this is not true of many mammals. A
few examples will clear this misconception.

The family of the Badgers and allied species affords a number
of examples of black uzder parts, and either white or light-coloured
upper parts; and most of these are xocturnal animals, so that we
cannot consider their contrasts of coloration as having had much to
do with a natural selection origin, by way of warning colours.
138 STUDIES IN THE EVOLUTION OF ANIMALS

Then in the Natural History Museum we find that Propithecus
coguerelt has the front of all four legs brown, and the posterior of the
legs and ack of the body wholly white; that P. coronatus is brown
on the abdomen and white on the back ; that P. Edwardsz7 is dark
brown everywhere except the posterior half of the back, which is
white; that Varesta varia is black on the abdomen and front of
legs, and yellow-brown on the back.

‘Further, the Egyptian Zorille or the parti-coloured Weasel has a
white back, striped longitudinally with intense black, and its ventral
surfaces and legs are black.

These might be sufficient to prove that light cannot be the
cause of this difference in the colorations of the upper and lower
surfaces of mammals. But if, in addition, we take that large class
of mammals, which have a dark back and a lighter-coloured abdo-
men, we shall find that, in many cases,—such as in the Gazelles, the
Black Buck of India, the black-backed Jackal of S. Africa, etc.,—
there is a distinct and very sharp line of demarcation, along the
flanks, between the two colours. This sharp line of demarcation
alone would be wholly opposed to the theory under review, for
there is no known property of light by which such a result could
be produced on the flanks of these animals. Moreover, the front
aspect of the legs of these animals is in most cases darker than the
hind aspect ; and we cannot suppose that the sun rays always beat
upon the legs from the front. It is obvious that in walking away from
the sun the Azzd@ aspect would be more lighted! The same objec-
tion can be brought against this view, in the case of those Antelopes
which have patches of white either in front or behind, and which
Dr. Wallace would call ‘recognition marks. Then what shall we
say.of all those Antelopes and Deer which, on a dark ground, are
either spotted or striped with white? Why have these white marks
not been obliterated by the light?
MAMMALS WITH CONTRASTED.COLOURS 139

What I have said is enough, I think, to prove that this light
theory is wholly untenable, at least as far as mammals are con-
cerned.

The reader might however say, Have you any other theory to
substitute for the light theory ?

Yes, I have, and it is this: I have endeavoured to show that
the spots and stripes of mammals are in many cases pictures of
ancestral armour-plates, modified subsequently in hundreds of ways
in some, or wholly obliterated in others. :

Well, the same theory of descent from armour-plated saseslhy
will explain why there is on the flank of many animals that sharp
line of demarcation between the dorsal and the ventral colouring.
That sharp longitudinal line indicates the margin of the ancestral
carapace, as we see it in the Armadillo, the Glyptodon, the Pango-
lin, and others.

Curiously enough, the little Armadillo of Argentina (Chlamy-
dophorus truncatus) has its armadilloid armour sharply truncated
posteriorly, and its rump is patched up by a differently plated
perpendicular shield. This curious appendage, according to my
view, might perhaps account for that white patch which so many
ruminants have behind, the line of demarcation between the dark

1 Tam aware that in the cases of peaches, apples, pears, etc., light colours their cheeks,
and I have seen a peach, partly shaded by one leaf, not acquire colour under the leaf.
But I am also aware that round the stone of certain peaches there is the same red colour
we see on their cheeks, while the intermediate thickness (sarcocarp) is either white or
yellow, and this central redness could not be produced by light in its ordinary sense.
Then there are the purple aubergines, which acquire their intense colour also on the
shaded sides. And I have been informed by a noted horticulturist that he has seen
the black Hamboro’ grape beautifully coloured when the roof of the house was almost
wholly shaded by the leaves. He also told me‘that he has seen the red seakale and the
red rhubarb grown in total darkness, and the tips of their leaves nevertheless always
acquire a red tinge. Moreover, we do not see the sweet-water grape colour, although grown
outside and fully exposed to light. I think if we substitute electricity for light, acting on
certain chemical ingredients, we may perhaps be nearer the right explanation.
140 STUDIES IN THE EVOLUTION OF ANIMALS

back and light-coloured rump being very sharp. It might mean
that the ancestors of those ruminants fad that rump shield, and
that it was got rid of earlier than the dorsal carapace, and thus a
sharp contrast of coloration was inherited in consequence. There
is an alternative supposition, for in some Armadillos we find that
the carapace stops short of the tail, and leaves a bare space
between the tail and posterior margin of the carapace, and this
fact may remain recorded in the ruminants and others that have a
white patch behind. It would seem to mean only a continuation
of the unarmoured ventral surface.

Among the animals that are so patched behind are the
Siberian Roebuck (Capreolus pygargus), Wapiti Deer (Cervus
Canadensis), Pronghorn (Axntilocapra Americana), Bonte-bok
(Damalis pygarga), Sable Antelope (Azppotragus niger), Scemmer-
ing’s Antelope, and several others. It may be quite true that
animals now make use of these white patches as ‘ danger: marks,’
and ‘recognition marks, but their origin is I think explained
by the abruptly truncated dorsal armour of some ancestral form.
In the ‘Pichiciago’ Armadillo of Argentina, the vacant space
is covered by an additional rump-shield, but in others it might be
absent, as we indeed see it in several other varieties of Armadillo.

In this connection I would mention that in the Natural History
Museum there is an interesting and very suggestive preparation
of this little Armadillo. It has no calcareous or bony carapace—
but only the epidermic horny shell of one. Under this horny shell
there is a hairy coat as in other animals. The curious part is, that
the horny shell is attached to the true skin by means of a thin
ligament all along the spine. This latter feature may perhaps
give us a clew to the interpretation of that spinal dark or white?

1 The Kerry breed of cattle are black, with a white streak down the back, and
sometimes another along the belly.—(Roy. Mat. Hist., vol. ii. p. 168.)
MAMMALS WITH CONTRASTED COLOURS 141

stripe which so many animals present. This may perhaps be a
vestige of the attachment of this dorsal ligament in some ancestral
form, during the ¢vansztion between the stage of plate-armour and
the stage of hair-covering. The spinal dark or white stripe of
certain animals might indicate that the general colour of the surface
altered eartzer than the spinal surface, and therefore had time to
become contrasted in colour, I will not however press this point,
should the reader think it preposterous. It may be looked upon
as a mere suggestion.

My contention is that the differently coloured dorsal and flank
regions of certain animals, as contrasted with the coloration of the
abdominal surface, is a vest7ge of the ancestral armoured carapace,
the sharp line on the flank indicating its margin, while the white,
or differently coloured abdomen, as in the Badger, the Egyptian
Zorille, and others, would indicate the wzarmoured ventral surface
of the ancestral forms. The origin of the white patch behind
would fit into this theory, and would indicate the truncated
posterior margin of some ancestral carapace,

In studying the Armadillo, we find that the abdomen, legs, and
under surface of the head and the throat are almost denuded of
scales, and much more so are the hind-legs of Kappler’s Armadillo.

Then in some Pangolins, we also find that the under surface of
the head, the throat, the inner aspect of the legs, and the abdomen,
are devoid of scales.

It can readily be understood that scales on those parts would
prevent the animal from rolling himself up for defence. The loss
of scales in those parts, while it gave him greater freedom of move-
ment, enabled him to roll himself up, and protect those unarmoured
surfaces, just as a Hedgehog would do.

Now in the Black Buck (Antilope cervicapra), instead of
armoured and unarmoured surfaces, we find simply contrasts of
142 STUDIES IN THE EVOLUTION OF ANIMALS

coloration in homologous surfaces, viz., the forehead and nose, the
body and outer aspect of the legs, and upper surface of the tail are
black, and the under surfaces, corresponding with the unarmoured
surfaces of the Pangolin, are whzte. This, in my judgment, means
that the ancestor of the Black Buck lost its armour on what are now
white surfaces Jong before it lost it on what are now dark surfaces,
so that those had the opportunity of having their pigment
modified, and so becoming contrasted by the time the descend-
ants wholly lost their armour. And the only thing now left to tell
the tale of ancestral armour in many animals is solely this contrast
of coloration, which in certain animals still remains, as a survival of
a feature which in remote times may probably have been gezeral.

In the Horse, through innumerable selections, this contrast of
upper and lower surfaces has been mostly extinguished, although
Horses of a brownish colour are often met with which have the
lower surface much lighter than the upper. But it is in the coster-
monger’s Donkey that a great contrast is visible between the dark
back and flanks and white abdomen. In black-and-tan Dogs the
contrast between the two surfaces is very marked; and there are
variations in which the contrasted colours of the Dog are tan and
white, or black and white.

It is not improbable that as time goes on all traces of contrast
derived from armoured and unarmoured surfaces may disappear,
unless maintained for special purposes, either by natural or artificial
selection, or unless reversions to ancestral colourings occur.
Among domestic animals this obliteration has already largely
occurred, In wild animals we see this obliteration in the Lion, the
Puma, the Hare, certain Deer,? and others.

‘Jn the domestic Dog we see how readily the hair pigment is modified, even in one
generation, from black to tan, and from black or tan to white.

* The young of the Wapiti Déer is spotted, while the adult has no trace of spots.
—Cervus Canadensis, Science and Art Museum, Edinburgh.
MAMMALS WITH CONTRASTED COLOURS 143

Some Horses, as I said, show a light-coloured abdomen and
inner aspect of legs, but this is not common. Usually the lighter
colour is very partial, and nothing like what it is in the domestic
Ass, or the Black Buck. See Grevy’s Zebra, fig. 52.

Dr. Wallace, I think, is partly right and partly wrong, when he
says that the Rabbit has acquired the white colour on the under-
side of its tail by natural selection, so that it might use it as a
danger-signal. In my judgment it got the white colour by
inheritance from a remote ancestral uxarmoured surface, the white
colour being a vestige of that; while it may have acquired the
habit of turning up its tail, and showing the white banner, through
natural selection. We know, too, that other animals, under the
excitement of fear or anger, cock up their tail, so that it is no
wonder the Rabbit should do the same. The survival of those that
could perform this social function would follow as a consequence.
The Rabbit is a defenceless and timid animal. For its safety it has
to depend on its large ears, in addition to the faculty of running
into. holes when its ears declare that possible enemies are about ;
and turning up its white surfaced tail, when running home in the
uncertain light of the dusk, may be a very useful way of showing its
associates which way the holes lie.

This theory I am advocating will also explain why the front or
exterior aspects of all the legs of many animals are so often,
especially in Gazelles, differently coloured from the posterior or
inner aspects. Naturally the front and outer aspects of the limbs,
which received the brunt of the enemy’s attacks, would have been
differently armoured from the posterior and inner aspects. This is
the state of things in certain Pangolins, for instance. Something
may perhaps also be due to the likelihood of there being only a
limited amount of armour-material in the blood, and only those
parts which urgently needed protection could be supplied with it.
144 STUDIES IN THE EVOLUTION OF ANIMALS

The reader should understand that, as in the case of spotting,
innumerable modifications have occurred, through which, in many
cases, the sharp line of demarcation, between the ancestral armoured
and unarmoured surfaces, has been toned down into a graduated
passage from the dark dorsal to the light ventral colouring.

This theory, however, should not be driven too far, for it will
not account for every single hair that may be differently pig-
mented; but I think it will account for the general colouring and
spotting more satisfactorily than the older light theory. Then
human selection of animals under domestication, and natural
selection of animals in a wild state, will account for the vast
number of modifications we see in the coloration of animals.

I would ask the reader to glance at Fig. 72. Nothing, to my
mind, can be plainer than the tale its coloration and spotting
suggest regarding its descent, in spite of the great modification its
legs and its digestive apparatus have undergone to fit it for
surroundings totally different from those of its ancestors. Its
partially edentate upper jaw seems to tell:a similar story. This
Deer would seem to say, ‘My spots are the vestiges of ancestral
armour-plating, and that fringe you see on my flank is the vestige
of the fringe of differently-shaped plates which form the margin ot
the Glyptodon’s carapace.’

No one could look at the picture of MWeliivora Indica in Mr.
Blanford’s Mammalia of India (Fig. 46), without seeing in its well-
defined grey back a strong resemblance to a carapace; and the
picture-carapace of Putorius sarmaticus (Fig. 41), is still more
striking, as its vestigial carapace still retains the vestigial spotting
of its ancestral bone-rosettes.

Even the sheep in the London parks seem to tell you, ‘My
fleece is the substitute of my ancestor’s carapace. In those days,
my ancestor’s face, ears, hands, and feet, were unarmoured, and now
MAMMALS WITH CONTRASTED COLOURS 145

the hair ¢here is short, and ‘of a different colour from my fleece—:
that is either white, brown, or black. My relative the Wolf, who
in former days was my enemy, is now my friend and caretaker. He’

 

FIG. 72,—A Spotted Deer, from a photograph, C. R. 1393.,

too in his “fleece” shows distinct evidence of our common
ancestor’s carapace.’
If we turn to the White-backed Skunk, a good picture of which
is given in the Royal Natural History, vol. ii. p. 76, we find
K
146 STUDIES IN THE EVOLUTION OF ANIMALS

similar contrasts. The peculiarity of its contrasted coloration, the
writer says, is regarded as belonging to the class of so-called
‘warning colours.’ Mr. Poulton observes that such warning colours
would seem ‘to benefit the would-be enemies rather than the con-
spicuous forms themselves. ... . But the conspicuous animal is
greatly benefited by its warning colours. If it resembled its
surroundings, like the members of the other class, it would be
liable to a great deal of accidental or experimental tasting, and
there would be nothing about it to impress the memory of an
enemy, and thus to prevent the continual destruction of individuals.
The object of warning colours is to assist the education of enemies,
enabling them to easily learn and remember the animals which are
to be avoided,’

There cannot be much doubt that an animal possessed of such
a coloration and character, and also of such ‘nauseous and irritat-
ing artillery,’ as has been described, would be avoided, when its
means of defence had become known. But we cannot in any way
admit that it is its ‘stinking secretion’ which has caused this ‘ con-
trast of coloration.’ The animal itself no doubt has learnt that it
is not attacked, and this accounts for its ‘indifference to the pres-
ence of other creatures ’ which is said to be ‘ one of the most striking
characteristics of this animal and its congeners.’ Therefore the
contrast of coloration between the white upper surface and crown,
and the black under surface and face, must be attributable to some
other cause.

When the plan of coloration of this Whzte-backed Skunk became
once established by hereditary influences, it began to change like
everything else, wzless it were maintained by natural selection,
through the action of the surroundings, as has happened in the

case of the Leopards; and this change we see, further on, in a
brother Skunk.
MAMMALS WITH CONTRASTED COLOURS 147

We can understand that an animal something like a Pangolin,
when it got rid of its armour, and when hair was substituted for it,—
as indeed we see has occurred in the little Pichiciago—the hair
covering remained under the same nervous influences which by
habit its ancestors possessed when they “ad back-armour ; and in
all probability the contrast of coloration of the hair of some of.
the descendants is caused by the same nervous influence.

As a matter of fact we find that another animal, which we
might say is a drother of the Skunk we have been discussing, has
not this conspicuous warning coloration, although it’ possesses a
similar ‘nauseous artillery.’ This Common Skunk (so different from
the White-backed Skunk) has a black or blackish body, and ‘although
there is a great amount of individual variation, the white markings
usually take the form of a stréak’ on the forehead, a spot on the
neck, and two stripes running down the back. . . . In some cases
the white stripes do not extend beyond the neck, so that the back
is entirely black,’

In the Common Skunk, it would seem, the change of colour has
gone on to such an extent as to leave nothing but mere vestiges of
its ancestral carapace-like whzte back; and therefore the theory
of warning colours having been caused by ‘ mephitic’ influences
evaporates,

It can be readily understood that possible enemies who may
come within the sphere of its effluvium don’t require to see any
warning colours, they can self the animal from a long distance,
and would naturally leave a good space between him and them ;
so that the ‘ mephitic’ warning may continue without the so-called
warning colours.

One can hardly contemplate the Black-backed Jackal of South
Africa in the Zoological Gardens and not think its sharply defined
back related to an ancestral carapace. The Dingo of Australia has
148 STUDIES IN THE EVOLUTION OF ANIMALS

similar markings, but the black on its back is less marked. Very
probably, either the one or the other has given our black and tan
domestic Dogs their distinctive coloration, which, in some varieties,
becomes fan and white. These and many others, in my opinion,
owe that particular feature to an ancestral carapace, although the
separate spots—vestiges of bone-rosettes—may have wholly dis-
appeared ; they still persist, however, in the Dalmatian breed of
Dogs. |

I have seen a curiously marked Toy Terrier of the black-and-tan
breed. Its back was grey and sharply defined like that of a Badger,
and it was blotched and striped with black. And in the Natural.
History Museum there is a tiny Cheetah from the Cape which is
also curiously marked. Its back is grey like that of a Badger, and
the other parts are spotted. It is impossible to contemplate these
reversions without thinking that they must have a deeper meaning
than that of being simply accidental.

At the risk of wearying the reader with repetitions, let us now
try to recapitulate briefly the whole process, and endeavour to form
a clear conception of how these phenomena could have been
brought about.

First, we must assume that natural selection, as indeed is
admitted by modern biologists, must have had a great deal to do
with evolving, from previous modes of armour, with the help of
congenital variations, the forms of carapaces we see in the Glypto-
donts and Armadillos with plate-rosettes. The congenital varia-
tions in the plates of carapaces were presumably brought about
by changes in the central nerve-action. This action we as yet do
not understand, any more than we understand how thought is
evolved from it. There can be no doubt however that in the
higher animals it is all-important, and governs everything.

This original nerve-action, however caused, by which a rosetted
MAMMALS WITH CONTRASTED COLOURS 149

carapace was elaborated, became confirmed by ages of usefulness.
In other words, the nerve-centres acquired the addt of acting
that way.

Then when, from whatever cause, the calcareous matter of the
exoskeleton disappeared, the nerve-centres continued that ‘same
action, which resulted in pigment pictures of the ancestral plate-
rosettes on the supple and elastic unarmoured skin. This is not
all, for the margin of the carapace was also pictured by contrast of
colour between the upper (ancestrally armoured) and the lower
(unarmoured) surfaces ; the margin remaining pictured even when
all traces of rosetting had disappeared.

Then innumerable further modifications in the atomic constitu-
tion of the nerve-centres, in which natural selection no doubt has
played a great part, have resulted in all the varied colorations of
mammals we see.

Of course it is impossible to say what atomic changes in the
nerve-centres produce a dark back and a light abdomen in some,
or a light back and dark abdomen in others, any more than it is
possible to make out why one animal turns out albino, and another
_melanoid, or why in one very dark grey Horse, with only few
-vestigés of spots, its mane and tail were pure white.

Some might perhaps fancy that they account for changes in
coloration by saying, ‘Oh! that is an a/bzno,’ or ‘that is a case of
melanoid variation. But this in no way explains its cause any
more than if one said it is a ‘ whitino,’ or a ‘blackino’! We are
at present wholly unable to say why, in a litter of black-and-tan
puppies, one comes out wholly tan, or tan and white; or why, in a
litter of tan puppies, one comes out wholly black, or wholly white.
All we can say is that these phenomena do occur.

This we may say; in the Jaguar these changes of colour occur
in the components of the rosettes themselves. What I conjecture
150 STUDIES IN THE EVOLUTION OF ANIMALS

was ancestrally a big central plate is now in the rosette of the
Jaguar a drown patch; and what were the encircling platelets are
now dlack spots, or a fusion of them forming a black ring, the whole
rosette being of a different colour from the general fawn colour of
the inter-rosette spaces. These three distinct colorations, well
marked in the Ocelots, suggest atomic Jocalised differences in the
nerve-centres: of which at present we know nothing.

Why in the Cats the spots are black, and in the Deer they are
white, I am unable to say. I find it also impossible to determine
whether the grey dappled Horse is an albinoid variation of the
brown dappled Horse, or the latter is a me/anodd variation of the
‘former. I must leave such questions for others to answer who
may know more about the matter than I do.

All I am here concerned with is, that there zs in many animals
a sharp line of demarcation between the colouring of the back and
that of the abdomen, and this I attribute to ancestral differences of
armoured and unarmoured surfaces.

No one who is imbued with the principle of evolution can
contemplate the skin of the Jaguar in Fig. 4 without saying,
Yes; the whole thing is a picture of armour-plating. This is not,
however, all, for that skin, in the different mode of rosetting be-
tween the dorsal and the ventral surfaces, and in the difference of
general coloration between the upper and lower parts, gives also
evidence, at least to my mind, that the lower lost their armour
before the upper parts.

This theory does not attempt to account for the variations of
nerve-centres. Those must be relegated to congenital causes we
-do not yet sufficiently understand, and perhaps to the action of the
environment.

In another part I shall endeavour to show that armoured
mammals must have been originally and ancestrally armoured all
MAMMALS WITH CONTRASTED COLOURS 151

over, that is, dorsally and ventrally, like the extinct Ganoids and
existing Crocodiles ; and that in dispensing with their armour they
first lost it on their ventral aspect, and second, and much later, on
their dorsal aspect also.

At the risk of seeming tedious, I repeat that this, in my opinion,
is the reason why so many mammals present a distinct contrast
between the coloration of their dorsal and ventral aspects with a
sharp line of demarcation between the two. Of course later on
there may have been a fusion of the two distinct colorations, and
all traces of demarcation wholly obliterated. Examples of this
obliteration are seen every day among Horses, Dogs, etc.
RESEARCHES AND DISCUSSIONS TO
CONNECT, MORE SURELY, ~-ARMOUR-
PLATING WITH SKIN-PICTURING
‘We can only say generally, with Darwin, that selection works by the accumulation of
very slight variations, and conclude from this that these ‘‘ s/ight variations” must possess
selection-value. To determine accurately the degree of this selection-value in individual
cases is, however, as yet impossible.’

The All-sufficiency of Natural Selection, by Professor AUG. WEISMANN,
Contemporary Review, September 1893, p. 322.
,
PART V
RESEARCHES AND DISCUSSIONS TO CONNECT, MORE
SURELY, ARMOUR-PLATING WITH SKIN-PICTURING

Is there any tangible evidence to prove that skin-spotting is
often the result of ancestral armour-plating ?

To answer this question we have to take a wider view of
vertebrate animals.

There is a great number of existing animals, which now have
only a partial and scattered armour, evidently a mere vestige of
a more complete and closer fitting ancestral armour.

The partial or complete disappearance of the bony plates of
the exoskeleton, from whatever cause, not unfrequently leaves spots
or other marks on the skin, in their stead, as records, so to speak,
of what had gone before.

I shall give only a few instances from fishes, which can be seen
in the Natural History Museum and in other records.

A Ray-fish with a whip tail, labelled Urogymnus asperrimus, has
a broad carapace, from head to tail, studded with closely-set plates
of two sizes, viz., large stellar and spinose plates, encircled by minute
tubercular platelets, the tail being wholly encased in similar plates.

Then an allied Ray-fish (a sting ray) from the Australian waters,
Trygon tuberculata, has only scattered spinose plates on its head
‘and sides, and a complete spinal line of similar plates, running into
‘the tail, which is also covered with spinose plates. —

Of another allied species, also from the Australian waters,
156 STUDIES IN THE EVOLUTION OF ANIMALS

Trygon brevicaudata, there are two specimens, (a) with a smooth
skin, seven plates on dorsum of tail, and minute scattered plates
on other parts of the tail; (4) also with a smooth skin, but with
several sfots on both sides, and only eleven plates on dorsum
of tail besides other minute tail-plates.

This series of fishes is very instructive, and there is no good
reason to doubt that in the latter the spots are partial vestiges of
the more complete armour of Urogymnus asperrimus. The back-
armour and tail-armour of the latter would lead us on, in the course
of ages, to the huge carapace and curious tail-armour of the
Glyptodonts.

There are many spotted Sharks, and the spinous Shark (Echzn-
orhinus spinosus Gmelin)+ is dotted with spinous plates, some
isolated, others confluent in groups. It seems probable that these
are only vestiges of an ancestral and more complete carapace.

Then there is another fish in the Natural History Museum which,
in this connection, is very instructive. It is the Servanus gigas of
Muscat. It is a large scaly fish in one of the middle cases. The
horny scales of fishes can only be considered as a modification of the
bony armour-plates, like those of the bony Pike and extinct Ganoids.
Well, the large body scales of this Serranus have each a black dab.
On the cheeks of the fish? the scales become thinner and thinner,
and almost amalgamated with the skin, each scale still retaining
the black dab. Then on the lips of the fish the scales disappear,
but the black dabs or spots remazz.

Of course the spots in this case are not exactly identical in
genesis with those of the Jaguar skin, unless we suppose that the
Glyptodontoid ancestors of the latter, besides their bony plates,
had also a corresponding set of horny plates, like those of Arma-
dillos, and spotted analogously to the spotting and marking of the

1 Science and Art Museum, Edinburgh. ? Technical terms are here unimportant.
ARMOUR-PLATING AND SKIN PICTURES 157

carapace of certain land Tortoises. The black dabs on the scales

of Serranus are as distinct from the skin
Peacock’s feathers, yet where the scales are
suppressed, the dlack dabs remain.

A striking example of stamps remaining
on the skin after plate-armour has disappeared
is to be seen in Serranus hexagonatus! All
over the surface it has hexagonal markings
independent of the scales. These markings
forcibly recall the hexagonal armour-plates
of the Ostracions. Then Serranus Merra has
the marks passing into confluent blotches,
while S.. Sonneratit, Pl. vii., Fig. 1, has similar
hexagonal marks, but only on the fore part
of the body and head, being totally obliter-
ated on the rest of the body.

The singular markings of these species
of Serranus are quite paralleled by the
markings of the fully dappled and the
partially dappled Horses.

Then in the York Museum I found an

Ostracion, with plates shown in Fig. 66 (4).

as the ocelli in the

 

Fic, 73.—Back of Scelido-
saurus Harrisoni, as re-
stored in Hutchinson’s
Extinct Monsters, pl. 8.

They were marked

with six dark spots. Well, this fish on its tail had no plates, dwt

only the black spots.

“Then if we look at the. back of the Dinosaur, with rows of
detached plates along its spine, as restored by Mr. Hutchinson

(Fig. 73), we shall see that if the plates disappeared, rows of spots

might be the result, like those along the back of certain Leopards.

I know that there are puzzlers among the markings of fishes,

such as. the Leopard markings of 7rygon uarnak, and the Giraffe
a Fishes of India, by Francis Day, PI. ii., Part. 1. Fig. 3.
158 STUDIES IN THE EVOLUTION OF ANIMALS

markings of Murena tessellata, and others, but one cannot be
expected to tackle the whole of creation at once, and the interest-
ing spottings and markings of fishes must be left for some future
investigation. By that time experimenters on the spotting of.
lower animals may perhaps be able to give us something definite
as to their cause.

This I know, that, even in plants, hairs or spines are often
accompanied at their base with spots, and when the hairs disappear
the spots remain. Here are a few instances: Begonza argenteo-
guttata has spotted leaves, and each spot has a hair, which is the
plant armour, while in Begonza Rex the leaves are piebald, that is, a
number of spots have become confluent. Some varieties of this
remain haired all over, while others have lost their hairs. Then
in Begonia maculata the spots remain, but the hairs are suppressed.

The deposition of dermal plates in animals undoubtedly
depended on heredity, the action of nerve-centres, and an available
supply of lime-salts, so that, as I have stated further on, when the
plates ceased to be developed, from a deficiency of lime-salts in the
blood, the nerve-centres, still continuing their influence, would have
brought about changes in the pigmentation, which now, in certain
cases, picture the plates themselves.

The main evidence, however, of the Jaguar and Leopard
having descended from plate-armoured ancestors is in the resem-
blance of their pigment-rosettes to the plate-rosettes of those
extinct mammals;! the same nerve-action which gave rise
to bone-rosettes was certainly equal to produce pigment-
rosettes, from which the hairs grow. That hairs will often grow
as soon as there is a part of the skin free from plates is sufficiently
proved by the Hairy Armadillo, and some of its congeners.

‘In the Tring Museum, as already mentioned, there is a Jaguar which, on the flanks,
has very large polygonal rosettes with sazzy (from one to six) spots in the enclosed space.
ARMOUR-PLATING AND SKIN PICTURES 159

Indeed, Professor Parker! has shown that in the embryo of the
Pangolin the scales are nothing but matted hairs, and the inter-
vening spaces are also covered with hairs, so that the substitute for
bone and horn armour, in mammals, seems to be hair or wool.

The description of spotting phenomena in animals by words is
a feeble thing compared with illustrations by photography, but to
photograph every modification would require a library, and not
one book.

The general colouring of a mammal is of little importance,
because we know that this varies very much ; but if the markings
are constant, though the general colour changes, we must infer that
they have a different and a deeper meaning than the general
colouring. 4

In Pigeons, the wing-bars ‘very often remain, although the
general colouring may vary ad infinitum. There are grey and also
cream-coloured Pigeons with brown bars, and blue Pigeons with
black bars, and so forth. And Dr. Wallace mentions? that in the
skirts of the forests on the Amazon, and in the larger ‘ilhas, both
the black and spotted Jaguars are often found. By black, I
presume he means the melanoid variety with distinct rosettes,
which can readily be distinguished in certain lights. We see a
similar persistence of markings in the Snow Leopard, although the
ground colour has changed to white? ;

From all this persistence of markings, as something distinct
from the general colour, I would infer that the markings havé a
deeper meaning than the general colour, and the meaning I would
attribute to these persistent markings in mammals is that they
have been inherited from such more remote ancestors than those

. 1 Mammalian Descent. 2 Travels on the Amazon, p. 63.

2In the Tring Museum I saw two varieties of Snow Leopards ; (a) with oced/ated
rosettes, and (4) with a large number of the rosettes sold, especially on the shoulders,
haunches, and lower flanks.
160 STUDIES IN THE EVOLUTION OF ANIMALS

which have given them their general colour, that is, from an
ancestry in which plate-armour had been established for ages.

I would repeat that the sfotting is the important feature, and
not the colour of the spotting—for we see in the Cheetah, black
spots on a light ground, and in the Deer, white spots on a dark
ground, and in the Kerry Cattle we see a white spinal line, instead
of the ordinary dark one. The reader might say—Is it reasonable
to suppose that an armour-plate should leave an impression after
the bony plate had totally disappeared, and should continue to be
pictured in the descendants for innumerable generations? It does
seem strange that this should be so, but impressions are left from
far more transient causes than the carrying of bony plates on one’s
skin for perhaps millions of years.

Mr. W. B. Croft, in a communication to the Physical Society,?
has shown that impressions of coins can somehow be left on a
clean glass, invisible at first, but made visible by breathing on the
glass; also that an impression of a paper, printed only on one side.
can be invisibly taken by pressing it between two plates of glass.
The printing can be brought out by breathing on the glass which
was opposed to the printing. What is more curious is that a
similar print-impression is given to the glass which does xot face
the printed surface. This latter impression can also be brought
out by breathing over the glass surface, and it is evidently
produced through the paper. Presumably light may have some-
thing to do with these impressions. But if so slight and temporary
an influence can leave an impression on the glass, what wonder
would it be if the armour-plating, carried for who knows how many
ages, should have so modified the skin, and its nerve-centres, as to
transmit plate-pzctures, even when the calcareous plates had totally

disappeared ?
1 Reproduced in Year Book of Science for 1892, p. 16.
ARMOUR-PLATING AND SKIN PICTURES 161

My object in all this discussion has been to endeavour to
discover why the Tiger and Zebra are striped, why the Jaguar and
the Leopard are rosetted, and the Deer and Horse dappled, and why
there are so many animals of different classes which have ringed
tails. The skeletons of all these animals inform us that they are
all related structurally, and therefore they must have come from
some common ancestral source, if not from the same pair of
parents, certainly from the same class of parents.

In another place I have shown that the same pattern of armour-
plates can be traced, through the Crocodile to the Sturgeon, and
perhaps also much lower down in the scale of life.

Professor Huxley! says: ‘ If the doctrine of evolution be true,
it follows that, however diverse the different groups of animals and
of plants may be, they must all, at one time or other, have been
connected by gradational forms; so that, from the highest animals,
whatever they may be, down to the lowest speck of protoplasmic
matter in which life can be manifested, a series of gradations
leading from one end of the series to the other, either exists, or
has existed,’

Professor Alleyne Nicholson in his Szwzney Lectures of 1893
repeated the same thing. He told us that all forms of life on this
earth originated from pelagic low forms like those still in existence
in the oceans.

But what is there to show that in the picture-plating of the
Jaguar the enclosed space is homologous with the larger middle
bone-plates of the Sturgeon, the Crocodile, the Glyptodon, etc. ?
There is nothing to show this beyond the difference x colour of the
enclosed space in the Jaguar rosettes as compared with the general
ground colour of the animal’s skin, I have endeavoured to empha-
sise this difference of colour in No. 9, Fig. 59. The shaded space

1 © Science and Hebrew Tradition ’"—Lectures on Evolution, p. 89. ;
L
162 STUDIES IN THE EVOLUTION OF ANIMALS

between the rosette blotches indicates the enclosed space, but the
Jaguar skin of Fig. 4 sufficiently shows that the enclosed spaces of
the rosettes are of a different and deeper shade! In some Ocelots
the enclosed space is quite brown. This difference of colour would
certainly indicate that in the nerve-centres there was some differ-
ence, although of an atomic character, in the cells which regulate
the colour of the inside and of the outside of the rosettes. In all
probability the atomic difference is of the same nature as that
which caused a large plate to be deposited in the centre of the
armour-rosette and a ring of small ones outside it. What we have
to note is that there zs a difference between the inside and outside
of the Jaguar and Ocelot rosettes.

Why this is so we do not know, any more than we know why
one Horse is dun, another bay, a third brown or black ; why a dun,
a bay, a dark grey, and even a black Horse sometimes has a pure
white mane and tail, and so forth.

To sum up, in the existing Jaguar coloration we have the
following elements, no doubt much modified from those of the
ancestral Jaguar :—

(a) We have the general ground colour of a rich tan between

the rosettes ;

(6) We have the spots more or less fused, which make up the

polygonal rings of the larger rosettes ;

(c) We have the enclosed space, which is often of a darker hue

than that of the ground spaces ;

(d@) We have those curious central black spots.

Now I have elsewhere mentioned that tan colour is interchange-
able with either white or black, and so we have the general colour
changed into either brown or black in the black Jaguar.

7 In the photograph this is decidedly shown, but in the illustration the difference of
colour is not so clear.
ARMOUR-PLATING AND SKIN PICTURES 163

The enclosed space a/one may change into black, and so obliter-
ate the space and turn the ocellated rosette into a so/zd rosette, as
we see it in the Serval (Fig. 17); or the rosette may be so con-
tracted as to obliterate only the middle spots, as in most Leopards.
Finally, we may have the whole surface changed either into a jet
black, obliterating all traces of rosettes, as in the black Leopard of
Johore, and the jet black domestic Cat; or the surface may be
changed into a uniform rich isabelline colour, as in the adult Puma;
or the ground colour inside and outside the rosettes may change to
white, as in the Snow Leopard. A further obliteration of all colour
produces the albino domestic Cat.

In all this theorising about the descent of rosetted, spotted, and
striped animals from carapaced ancestors, it should be distinctly
understood that I do not in the least maintain that the Jaguar or
Leopard descended from ¢hzs particular Glypiodon, or that particular
Dedicurus. What I mean is that the Jaguar and Leopard bear on
their skins the stamp of having descended from a@ carapaced
ancestor, which had bony rosettes something like those of a Glyp-
todont. How many bone-rosettes, and of what exact shape they
were, in this conjectural ancestor, I am not in a position to say.

In this discussion the whole evidence is circumstantial, for no
one has ever seen the passage of a Glyptodon’s carapace into the
rosettes of the Jaguar. One would indeed require to have lived a
good bit of time to witness a Glyptodon changing into a Jaguar,
considering that Cuvier found no appreciable difference between
the skeletons of the ancient mummified animals of Egypt and
their representatives which lived 3000 or 4000 years later.t

In these and similar investigations circumstantial evidence is
the only kind of evidence obtainable, and it is very valuable. The
connecting gradations must be filled up by the imagination.

1 © Science and Hebrew Tradition ’—Lectures on Evolution, p. 77.
PROBABLE MEANING OF SOME INTEREST-
ING FEATURES IN HORSES AND
OTHER MAMMALS
‘ Positively, the principle may be expressed, in matters of the intellect, Follow your
reason, as far as it will take you, without regard to any other consideration. And
negatively, in-matters of the intellect,-Do not pretend that conclusions are certain, which
are not demonstrated, or demonstrable.’

From Professor HUXLEY’s Definition of Agnosticism.
PART Vi

PROBABLE MEANING OF SOME INTERESTING
FEATURES IN HORSES AND OTHER MAMMALS

BESIDES the dappling which I have tried to account for, Horses
have certain other marks which are very common indeed, and
which are more conspicuous in self-coloured Horses, such as bays,
browns, blacks, etc.

For instance, Horses very commonly have what is called a
white ‘blaze’ all over the front of the face down to the mouth; or
a simple white star on the forehead, which varies between a mere
white speck and a white patch.

Then there are intermediate stages as shown in Fig. 74. Some-
times the ‘blaze’ is interrupted, a white patch being on the fore-
head, and another on the nose, and so on. Finally every trace of
the white blaze may be obliterated, and the whole face is of the
same colour as the body. Frequently, however, in dark and dun-
coloured horses the blaze is black, and in dark grey horses it is of
a sooty grey, more or less interrupted, on a lighter ground.

Now, is there any way of accounting for this feature, so common
in the domestic Horse? One day, in Piccadilly, I saw standing a
dark grey cab Horse. On its forehead it had three pairs of faint
radiating stripes of a grey colour on a white ground—as shown in
Fig. 75 (a). It struck me that these might be vestiges of the Zebra
face-marks. There happened at the time to be a stuffed specimen
168 STUDIES IN THE EVOLUTION OF ANIMALS

of Burchell’s Zebra in Rowland Ward’s window ; so I went over to
look at it, and found that the marks on this Horse’s face corre-
sponded to three pairs of similarly radiating stripes on the Zebra
face, as shown in Fig. 75 (0).

In studying this curious feature further, I came to the con-
clusion that the dark blaze on the dark grey Horse, and on some
bay and dun-coloured Horses, was a more or less complete /uszon
of the s¢riges we see on the Zebra’s face, thus forming a dark blaze.

  

Fic. 74.—Diagrammatic sketches of the faces of Horses ; (2) shows a full white ‘ blaze’ ; (@)
a white star on the forehead; (é and c) intermediate contractions of the ‘blaze’; ( x} indicates
the white part on a dark ground.

Then, as black is interchangeable with white, in some dark Horses
we see a complete w/zte blaze, occupying the whole of the lozenge-
shaped face of the Horse, as shown in Fig. 74 (a). The other
figures (6 and ¢) are mere contractions of the blaze, until we come
to a mere vestige of the blaze in the shape of a small white star
between the eyes, which, in others, becomes completely obliterated.

It would be tedious to go through all the variations that this
blaze is subject to; suffice it to say, that it sometimes invades the
whole head, while in others it disappears completely.
INTERESTING FEATURES IN HORSES, ETC, 169

‘TI have seen a Horse with a blackish star on a white blaze, and
others, mostly bays, with a white star on a black blaze. This
shows that although usually the star is white, it may, under certain
circumstances, be exchanged for a black one; and although
usually the blaze is white, it sometimes can also be black. I have
seen a perfect Slack blaze on the face of a light dun Horse. It was
as full as the complete white blaze of (a) Fig. 74.

These features in the domestic Horse are so persistent, even
when all other spotting from the body has wholly disappeared, that

 

Fic. 75.—(a) Faint radiating stripes on the forehead of a dark grey Horse ; (4) black radiat-
ing stripes on the forehead of Burchell’s Zebra—note its lozenge-shaped face.

they would seem to have some deeper meaning than mere
accidental marks, It is interesting to note that even the Zebra
may have a small black star on its forehead between the eyes, as
seen in Fig. 50.

The persistence of these features may be because domestic
Horses have been bred originally from parents that had them.
Breeders of first-class Horses, I understand, would rather not have
either stars or blazes, and it may be presumed that they have
170 STUDIES IN THE EVOLUTION OF ANIMALS

endeavoured to select them out. Yet it is only exceptionally that
they have succeeded in getting rid of them, for the large majority
of Horses of all kinds one sees in the streets of London have these
frontal marks, either fully developed or with vestiges of them ; so
that I think we would be right in concluding that they come from
a remote ancestry.

‘Our grandfathers have told us how their fathers expatiated on
the merits of the Dutch Horses (old Lincolnshire blacks), of their
size and feats of strength, how the blacks with white legs and
blazes were most esteemed. These animals, or their descendants,
in time became located all over England.’

This would appear a sufficient reason why blazed horses are so
common in the streetsof London. They got it from the old Dutch
Horses, ‘which with white legs and blazes were most esteemed’

But this is not all, for Mr. F. Finn tells us? that ‘The Onager
was put to an Abyssinian wild Ass, and produced a hybrid; it
then bore, to a male Onager, a chestnut foal with a white blaze on
the forehead ; but as this foal thus resembled neither parent, and
in fact exhibited a Horse’s rather than an Ass’s marking, the case
is surely one of analogous variation,’

The names of the equines appear to me to be mere verbal
distinctions used by systematists in classifying animals: In
nature there seems to be no such distinction between Horse, Ass,
Onager, Zebra, and Quagga, more especially as they all zzzer-breed.
And this blaze on the forehead of the chestnut Onager’s foal seems
a reversion to some ancestral mark—white or black—whether we
call the ancestor a Horse, an Ass, an Onager, or a Zebra. In this
foal the blaze was whzte, but I have shown that the blaze may have

originally been d4/ack, and caused by a fusion of the stripes on the
‘Pedigrees of British and American Horses,’ by J. I. Lupton, Wineteenth Century,

June 1894, p. 926,
2 “Some facts of Telegony.’—Matural Science, December 1893, p. 437.
INTERESTING FEATURES IN HORSES, ETC. 171

Zebra's face. ‘Ne have seen that white, black, and tan are zxter-
changeable. Dark Horses have either white or black blazes; and
dun and roan Horses have sometimes conspicuously black blazes.

This interchange of colour—general or partial—occurs in various
other animals. The black and tan Dog turns into tan and white ;
the Dalmatian Dog is white, spotted black ; certain Deer are of a
tan colour, spotted white ; and the stripped American Marmot is of
a dark colour, with strings of white spots.

Besides Horses there are many other animals that have black
blazes on their face, such as several species of Antelope, several
kinds of Deer, Ibex, Goats} etc., and the Bonté Bok Antelope
(Damalis Pycarga) has a white blaze. Cattle have often a white
star on the forehead, which we might consider, as in the Horse, a
vestige of the white blaze.

We may perhaps infer that the black blaze is a fusion of the
Zebra’s face-stripes, as we have before inferred that certain
blotches and stripes on animals are fusions of isolated spots, but
why a black blaze should turn into a white blaze, or tan feet
should turn into white feet, as in the Dog, is more than I can tell.
It would. appear to be caused by a sort of atomic ‘conjuring’
of the nerve-centres hidden from our view even through the most
powerful microscopes. Anyhow, we have ceased to think of super-
natural causes for all these phenomena. There must be some
natural causes for them, although at present we do not know them.

All I know is that white, black, and tan colours in mammals are,
as I said, interchangeable, and therefore I surmise that the Horse’s
white .blaze may have been originally black, and that in some
varieties it changed into white, and has for some reason become
more persistent in this colour.

_Whether the blaze of the. Horse may have any relation to the

1 The male Bharal (Ovis Nahura) has a fine black blaze.
172 STUDIES IN THE EVOLUTION OF ANIMALS

insertion of the horns in some ancestral Rhinoceros is a question
difficult to answer. We have seen that in certain animals skin
armour has left certain marks when it disappeared, which are liable
to change of colour, and not impossibly the blaze on the Horse’s
forehead may be vestigial of ancestral frontal and nose armour.

It might lead to a certain amount of confusion to compare the
Horse now with a Rhinoceros, and then with a ruminant, but
Professor Alleyne Nicholson, in his Swiney Lectures of 1893, told
us that if we go back far enough in time we shall find that animals
which are now so distinct as ruminants and carnivora were in
remote times mixed up in ove animal, with features that had some-
thing of do¢h the branches into which that remote animal eventually
bifurcated.

According to Professor Weismann’s doctrine, the object of sexual
propagation is to mix up the separate descents of one individual
with the separate descents of another individual, with the view of
rendering the germ plasm more plastic and variable, so that it
may the better provide the raw material of variations in organisms
for the factory of adaptation by natural selection. We know that
the characters of two distinct species, even of two distinct genera,
were initially mixed up in one individual.

Well, in bygone ages, it is very probable that animals which
were largely differentiated in certain anatomical features were not
so differentiated phystologically as to prevent their being mixed by
sexual mating. If this be admitted, it would follow that what we
now would call distinct species, might then have freely inter-
married, and procreated what we now would call hybrids. For
instance, a mixture of hornless, one-horned, and two-horned
Rhinoceroses, if they happened to come together, might Have inter-
bred and become mixed. In past ages this may have been a
frequent occurrence. So with Antelopes, Horses, etc.
INTERESTING FEATURES IN HORSES, ETC. 173

Some one might say that intermixture would eventually have
produced an average structure, and all differences would be sup-
pressed. But this does not appear likely in all cases, for we know
that six-fingered people, although diluted with normal blood, have
rather strengthened than suppressed the monstrosity.

Such intermixtures are not at all imaginary, for we know iia
the Pheasant will procreate with the common fowl, and different
species of Pheasants will interbreed. And among plants, species
so distinct anatomically as a Lelia and a Sophronitis, a Cereus and
Phyllocactus, and a Gesnera and a Gloxinia, have been successfully
mated.t

The application of all this to the Horse is that in our modern
Horse we may have not impossibly the convergence of, not only two
distinct races of Rhinoceros—the one and the two horned; but
possibly also an intermixture of blood derived from some ancestor
of the Giraffe, and also of other ruminants,? when they were not
so differentiated as they are now.

If the reader should carry away the notion that I consider there
were once Horses with horns between their eyes and on their noses,
he will carry away a very wrong idea of what I mean.

The Horse is a very specialised recent elaboration, as his feet
testify, from some remote and more generalised form, which was
the raw material out of which various kinds of mammals, such as
Giraffes, and other ruminants, Rhinoceroses and Horses have been
evolved. Horses or Horse-like animals may never have had horns
homologous with those, of the Rhinoceros, but their ancestors may
have had them, and in the existing Horse, all that there is to tell
the tale of ancestral mesial horns may not impossibly be these

1 At the meeting of the Royal Horticultural Society on the 8th May 1894, Messrs. Veitch
and Son showed a hybrid (Gloxinia ‘ Brilliant’) between a Gesnera and a Gloxinia.

2%In the tuft of long hair over the nose of the white-tailed Gu, we may have the
dissociated hairs of which the Rhinoceros horn is said to be made up.
174 STUDIES IN THE EVOLUTION OF ANIMALS

frontal and face marks for which I have been endeavouring to
discover an explanation. The same nerve-centre habit of action
which, in ancestral forms, gave rise to horns, now that the Horse no
longer has horns, may display itself by producing a change of pig-
ment of the skin in the places once occupied by horns.

There is another feature in Horses for which I have been
endeavouring to discover an explanation.

When Horses change colour, it is only down to the ankle and
wrist that they usually do so; only rarely does the body colour
continue to the hoof ; so that we see bay, dun, roan, and dark grey
Horses with their hands and feet black; strawberry roans with
these parts bay or chestnut ;+ and we see Horses of various: colours
and even black Horses, with whzte hands and feet. What can be
the cause of this? Why should there be so frequently such a
distinction between the coloration of the hands and feet of Horses
and that of their bodies? It is only in pure whites, pure chestnuts,
pure blacks, that the hands and feet are usually of the same colour
as the body, but in the duns, or sponge-coloured horses, the black
hands and feet form a strange contrast to the colour of the body.

If we make investigations among other animals in the Natural
History Museum we find that the Ruffed Lemur has long hair
down to its ankles and wrists, and on its hands and feet the ‘hair
becomes short, and of a different colour, so that this animal looks
as if it had jet black gloves and socks.

The Alpaca has a brown body with long hair, and then suddenly
its hands and feet become short-haired and jet black.

The Gaur (Bibos gaurus) and its congenér the Javan Ox, have
white hands and feet, although the former has a black and the
latter a tan or dun-coloured body ; so also the Gayal (Bos frontalis).

1 Many roans when clipped are of a blackish grey, and strawberry roans either
bay or chestnut.
INTERESTING FEATURES IN HORSES, ETC. 175

The Inyala Antelope (7vagelaphus angasii) has a roan body
and tan hands and feet.

The Waterbuck (Kobus ellipsiprymmnus) is roan, with brown
hands and feet.

Then the ‘ Bonté bok’ (Damalis pycarga) is still more interest-
ing, for it has a white blaze on its forehead, like that of the Horse,
and also white hands and feet.

I do not think that the doctrine of natural selection will help
us much in deciphering these hieroglyphics.

The old Dutch Horse with white hands and feet and forehead
blaze, which was introduced into England and much esteemed,
may explain why there are so many Horses with these features in
England ; but it does not explain in the least why the old Dutch
Horse had these features; or why, when the black Horse changes
into dun, he gets d/ack hands and feet, instead of white, and often
also a black blaze instead of a white one.

Is there then no explanation of these contrasts of colours, such
for instance as those of a dlack Horse, with whzte hands and
feet ?

It will perhaps be more convenient to take a broader view of
these contrasted colours in certain parts of animals.

As I have said, the Horse has frequently its hands and feet
differently coloured from the rest of the body; the Dog has
frequently tan-coloured hands and feet, and a black body, or white
hands and feet and a tan-coloured body ; I have seen a white Goat
with black hands and feet. But besides these contrasts of the
hands and feet, there are others which we find in various animals.
The lips, up to a certain point round the mouth, a circle round the
eyes, a circle round the base of the ears, anda space round the
vent, are all frequently of a colour which forms a great contrast
with the surrounding ground.
176 STUDIES IN THE EVOLUTION OF ANIMALS

What is there in coon with all these parts? The reply is,
great mobility. If it be true that all mammals descended from
armour-plated ancestors, it must be evident that the parts men-
tioned were the earlzest to get rid of their armour in order that
their struggle for existence might be facilitated. If the hands and
feet were covered with hard scales, as in the turtle, it is evident
they could not be used to run and grasp; if the eyes were sur-
rounded by armour-plates, as in the Ganoid fishes, it is evident that
sphincter muscles, to close the eyelids and protect the cornea, could
not be developed ; if the base of the ears were not sufficiently
mobile to allow of the ear being easily directed towards the source
of sound, the muscles that perform that function could not be
developed ; so of the lips and vent. All these parts are highly
mobile, and must have lost their armour-plating earZy, in order to
admit of that mobility, and hence we see that these parts had
ample time to change their coloration long before the body got rid
of its carapace, or body-armour.

A number of animals show a complete or partial circle round
the eye, such as the Ocelot of Fig. 19 (a2). And also many Cats,
such as the Caffre Cat, the Pampas Cat, the Genet, the Binturong,
and several others;! and so have some tame Rabbits. Then a
number of animals have a spot, emphasised by contrast of colour,
over the eye like that of the black and tan dog ;? such as the
European Lynx, the Caracal, the Clouded Leopard, and others,
In many variations of the black and tan Dog, one often meets with
individuals which have a complete tan-coloured circle round the
eye.

1 See Royal Natural History, vol. i.

2 Mr. Worthington G. Smith states that, ‘The spots are by no means always tan; a
black Dog will sometimes have them white, and a white Dog black. I have a white and

tan Fox Terrier in which the spots are very eye-like and jet black; in a brown Bull-pug
of mine the spots are also black.’ (See Mature of 15th November 1894.)
INTERESTING FEATURES IN HORSES, ETC. 177

One would not suspect that the Horse came under the same
category, but I have seen a dark-bay Horse which had a semi-circle
below the eyes, and a spot above them, both of a tan colour,
and quite distinct from the general colour of the face. All
these seem to be no other than vestiges of ancestral circles
round the eyes, contrasted with the general colour by a different
pigment, and in all probability derived from the cause I have
hinted, viz. early loss of armour round the eye, to admit of
closure of the eyelids for the protection of the delicate structures
of the eye.

It must be obvious that in the transition of sea-animals without
eyelids, to land animals which moved about in dense forests, it was
of importance for them to acquire an unarmoured circle round the
eye, and the faculty of closing their eyelids to protect the cornea
from injury; and especially at night it was of importance that
long hairs should grow on the unarmoured circle round the-eye
such as we see in the white-tailed Guu, to warn them of the vicinity
of a branch, or a leaf, or other object, defore the surface of the
cornea came in contact with it, and thus enable them to close the
eyelids in time.

And so of the other parts in which mobility was of great
importance—the hands and feet, the base of the ears, the lips and
the vent. In some specimens of heads of the Black Buck which I
have seen, there was a distinct white circle round the base of the
ears, A large number of dark-coloured Horses and Asses have a
light-coloured mouth. The Cyprian wild Sheep? has a fine and
striking white muzzle, beautifully contrasted with the dark face.
Who would have thought that the origin of this white muzzle was,
in'all probability, the unarmoured muzzle of some animal not
unlike a Pangolin? All the coloration of this Sheep is indicative

1 Royal Natural History, vol. ii. p. 225.
M
178 STUDIES IN THE EVOLUTION OF ANIMALS

of ancestral armour which had passed through stages of partzal
-adtsarmour.

I have seen a whzte Pony which had the mouth, circles round
his eyes, and circlets just above the four hoofs, aé/ of a yellow or
rather golden-bay colour. It is evident that in these parts there
was some difference of innervation—a remote ancestral habit of the
nerve-centres—which prevented a ¢ofa/ albinism of the skin.

Of course, in the great battle of life, and the many adaptations
to surroundings to which animals have been subjected, and in the
fancies of breeders of domestic animals which have revolutionised
the coloration of a number of animals, it is not to be expected that
they could long retain the coloration of their unarmoured parts
unmodified. We therefore now see mere vestiges of ancestral
features. It is only occasionally, by a sort of reversion, that we
are let into the secrets of what may have obtained in remote times.
The very fact that so many different kinds of animals have these
features is sufficient indication of their antzgucty.

As I said, there is no hard and fast fxz¢y of coloration in these
parts ; there is not only an interchangeableness of black into tan,
or shades thereof, and of tan into white, but also an intermingling
of the coloration of contiguous surfaces, as well as a dwindling, in
many cases of the markedly coloured surface. For instance, we see
the white hands and feet dwindling to the last phalanges in certain
Cats and Dogs, and in Horses to a mere vestige of white just above
the hoof. In the Horse all four limbs may be white, or only three,
two, or even only one, may be white, so that the contrasted colours
often merge into the general coloration. The curious thing is that
in the Horse there would appear to be some correlation between
the mane and tail and the four feet, for all these are often of the
same contrasted colour, either black or white, or shades of tan,
when the body is of a totally different colour.
INTERESTING FEATURES IN HORSES, ETC. 179

It is very curious that the wild cattle of Cadzow Park? should
have d/ack muzzles, ears, and front parts of hands and feet, while
the rest of their body is white. It would seem that those parts
had originally a specially different function from the rest of the
body, which is now of a contrasted colour, while in the Gaur the
body is black, the muzzle pale, and the hands and feet whzte.

Then in the same work? it is stated of the wild cattle of
the Somerford Park breed, that ‘the colour is pure white; the
ears, rims of the eyes, muzzle, and hoofs being quite black. Like
all other herds of the forest breed they have a tendency to pro-
duce black spots on the neck, sides and legs.’

Surely this contrast of certain parts with the general coloration,
and this tendency to produce spots, cannot be the result of pure
accident. It seems that in the nerve-centres the ‘memory’ of
ancestral dermal conditions is now aroused, and now in abey-
ance, and so the results on the skin are now ancestral, and now
aberrant.

In speculating on the causes of these interesting phenomena,
we should not be led away by the bias of a theory, and shut our
eyes to any sidelights that may turn up in the course of our
research. I shall therefore put on record the following fact, so
that the reader may make of it what he can.

In the Tring Museum there is a fine specimen of Chapman’s
Zebra. It has the lower parts of its limbs for several inches above
the hoofs wholly black; while Grevy’s Zebra close by has those
same parts fully striped. It would appear that the black of the
former may be a fusion of the stripes of the latter; but at the
same time it would show that there was a difference of innervation
there, which caused this fusion.

Among the extinct Ganoid fishes there were several species

1 See Royal Natural History, vol. ii. p. 164. 2 Tbid. p. 167.
180 STUDIES IN THE EVOLUTION OF ANIMALS

with a circle of plates round the eyes, as shown in Fig. 76, (a)
and (4), and others in which the eyes were mere holes in a solid
one-piece head armour as in (c).1

In their descendants, the carapaced land animals, it may have
been this circle of plates round the eyes which was early got

az

 

l1G. 76,—(a) Circle of bone-plates round the eye, Legidotus maximus, p. 986; (2) Tuber-
culated bone-plates round the eye of Dapidius pholidotus, fig. 922; (c) Solid bone mask of
Cephalaspis Lyelli with an eye-hole at (e), p. 961 (all three Ganoid fishes from Manual of
Paleontology, by Nicholson and Lydekker,vol. ii.) ; (¢) is the head of Ostracion punctatus,
an armour-plated modern fish,with its unarmoured lips at (#z) from pl. 181, Fishes of India,
by Francis Day, pt. iv.

rid of to enable them to close their eyes, if necessary, while moving
among bushes, for the protection of their eyeballs. Then there is
that curious modern fish called Ostracion, which is encased in hexa-
gonal bone-plates all but the lips; the fins and tail also have no
plates round their base. Fig. 76 (d) gives a sketch of its head.

1 See Figs. 898, 922, and 926 of Manual of Paleontology, Nicholson and Lydekker.
INTERESTING FEATURES IN HORSES, ETC. 181

The still remaining spots on the lips and round the eyes suggest
to my mind that these parts also, in some ancestral form, were
encased in plates. The anal sphincter-muscle may similarly have
required the absence of calcareous deposit.

Then I should say that the early loss of armour round the eye,
round the mouth and vent, and also from the hands and feet, parts
acquiring great mobility in the struggle for life, is the reason why,
in the higher animals, these parts are so often contrasted in colour.
The early loss of armour gave those parts the opportunity of
becoming variously pigmented /ong before the rest of the body had
become uncarapaced. The base of the ears, and the lower parts, such
as those of the neck, abdomen, and tail, would follow the same rule.

That is, they lost their armour, replacing it by hair, long before
the other parts of the body lost theirs; and therefore they had
time to alter their coloration before the parts with which they are
contrasted had become armourless.

As shown in another place, we see frequent examples of altera-
tions in hair colour on parts occupied by hairless skin-structures
which became subsequently suppressed. The most convincing
examples of this are the tufts of differently coloured hair which
have replaced the callosities on the legs of certain ruminants (see
Fig. 85). From a minute study of animal coloration, it seems
clear that small portions of the skin can alter zdependently of
adjacent surfaces, or without the coloration of the whole surface
becoming altered.

But if we are anxious of being thoroughly convinced that this
ancestral loss of armour in certain parts is a vera causa of the con-
trasts of pigments in their existing descendants, we should visit
the Pangolins in the Natural History Museum.

There we find that the Malayan Pangolin (Manis Javanica),
and the long-eared Pangolin (Manis Aurita), have no scales on
182 STUDIES IN THE EVOLUTION OF ANIMALS

the under surfaces of the head, neck, chest and abdomen, and also
on the inner aspects of the four legs.

Then the yellow-bellied Pangolin (Wanis Tricuspis), as well as
others, has a muzzle wholly destitute of scales, and its under surfaces
and paws are hairy instead of scaly, The soles of its hind feet
from the heel to the toes are also dare; and this latter fact
will give us a hint why, in certain descendants of armoured animals,
such as certain Cats and Dogs, this very surface from heel to toes
in these digitigrade descendants is black, and contrasted with the
pigment of their adjacent surfaces.

It is true that these Pangolins still retain scales on the under
surface of their huge tails, but if we search further we find that in
the little Ant-eater close by (Cycloturus Didactylus) the under sur-
face of the tail is hairless, so is that of Horses; and this may be
the reason why, in the innumerable changes of skin coloration
which have occurred in mammals, the under surface of the tail is
so often contrasted in colour with the upper surface. Indeed,
the under surface of the tail is only a continuation of the
under surface of the body from the muzzle to the tip of the
tail, and the white tip of the tail we see in so many animals
may be only a vestige of a more extended whiteness of the under
surfaces.

Then do you mean to say that Dogs, Cats, Asses, Antelopes, etc.,
which have contrasted upper and under surfaces, are descendants
of Pangolins?

I mean to say no such thing. The Pangolins, as well as the
Armadillos, and these other mammals mentioned, are descendants
of a much remoter stock which had their bodies wholly armoured
up and down. Armour was first suppressed on the under surfaces,
and gradually replaced by hair, and the Pangolins and Armadillos
are survivals of that state of things. Other descendants of the
INTERESTING FEATURES IN HORSES, ETC. 183

same stock, and much later on, wholly lost their armour, and
acquired in their hair contrasted colours zustead.

So that in existing mammals we seem to have indications of
Jour distinct stages of evolution—

(a). Mammals which were wholly armoured, somewhat similar
to, say, the existing Crocodiles ;

(2). Mammals which were half-armoured, with hair on the lower,
and plates or scales on the upper surfaces, as in the existing Pan-
golins and Armadillos ;

(¢). Mammals which had wholly lost their armour, but retained
indications of their ancestral partial armour in their rosettes and in
their contrasts of coloration ; and

(@). Mammals which have lost or are losing every indication of
ancestral armour, such as the Puma, the Lion, the domestic self-
coloured Horse, the domestic self-coloured Cats, Dogs, etc

The white circle round the eyes and the white muzzle are well
shown in the white-nosed Coati of Central America. Its ringed
tail sufficiently indicates its descent from an armour-plated ancestor,
if the reader has been following this interesting discussion. But
the circle round the eyes is best seen in the parti-coloured Bear of
Eastern Tibet.1 This particular animal is very strangely marked.
It is white, with black rings round the eyes, and black ears, while
the shoulders are marked with a transverse black band broadening
towards the fore-limb. The under surface and legs are black.

The writer who describes it says: ‘Without knowing more of
its general surroundings, it is difficult to imagine the object of such
a staring contrast.’

Perhaps the coloration of this Bear has nothing to do with sur-
roundings as a cause of its ‘staring contrast, but may be a vestige
of an zucomplete ancestral carapace, viz. ‘that of a neck and head

1 Royal Natural History, vol. ii, Ps 33:
184 STUDIES IN THE EVOLUTION OF ANIMALS

shield, and a body and haunch shield, the shoulders and limbs, and
circles round the eyes, having ear/y lost their armour; while the
Cape Ratel, and the common Badger may have descended from
ancestors which had a more complete armour.

If the reader will turn to Fig. 79, of RAinoceros Sondaicus, he may
perhaps be struck with the possible homology of its scapular shield
with the staring scapular black mark of this parti-coloured Bear!
Even the fold in the groin of the Rhinoceros would seem to be
imitated by the black pigment in the Bear’s groin—and its white
head and neck are suggestive enough of the neck and head armour
of the Rhinoceros.

One would be tempted to infer from all this that the remote
ancestor of this Bear lost its scapular armour long before it lost
its other carapacial armour; and we know that the extinct Pola-
canthus had only a partial carapace on its lumbar and pelvic
regions.

In this and similar speculations allowance should naturally be
made for the transition of solid plate-armour to its copy in hair, and
for any modification the Bear-descendant may have undergone in
its coloration through the ages.

For instance, Ursus Americanus is wholly black, excepting its
muzzle, which is of a tawny yellow. The Zayra of the Weasel
family is usually of a dark brown colour, but occasionally white
specimens are met with, their muzzle, ears, and feet, however, remazn-
ing dark. Of course I do not in any way mean that this bear
descended from Rhinoceros Sondaicus, any more than I mean that
the Giraffe descended from a Zebu; all I mean is, that, in tracing
their origin backwards, the skin characters of certain mammals indi-
cate that they converge towards an armour-plated ancestry.

Professor Huxley says: ‘In former periods of the world’s history
there were animals which overstepped the bounds of existing
INTERESTING FEATURES IN HORSES, ETC. 185

groups, and tended to merge them into larger assemblages. They
show that animal organisation is more flexible than our knowledge
of recent forms might have led us to believe; and that many
structural permutations and combinations [I would take the liberty
of adding skin features],! of which the present world gives us no
indication, may nevertheless have existed.

“But it by no means follows, because the Palgotherium has
much in common with the Horse, on the one hand, and with the
Rhinoceros on the other, that it is the intermediate form through
which Rhinoceroses have passed to become Horses, or vice-versd ; on
the contrary, any such supposition would certainly be erroneous.’ ?

As I said, there is no fixity of coloration round the eye or other
part, as it may dwindle and disappear altogether, or it may invade
adjacent parts. Those animals which have a complete circle round
the eye, whether white, black, or tan-coloured, are survivals of a stage
which at one time may have been general, and the spot over the
eye of the black and tan Dog may be only a remnant of a former
complete circle round the eye.

On one occasion I saw a jet black Persian Cat. The tips of all
its four feet were white; it had a white patch on its chest, and a
little white on its abdomen ; its whiskers and eye hairs were white.
There was no contrast of colour round the eye and round the
lips—both being jet black; but these white whiskers and eye hairs
were seemingly the oz/y remnants of surfaces differently coloured
from the body.

There are other curious marks in some mammals which are not
so easily accounted for; such as the white tip of the tail in many
Dogs to which I have already alluded, and a white patch which one
sees so frequently on the chest of Dogs. There can hardly be much

1 The parenthesis is mine.
2 “Science and Hebrew Tradition.’—Lectures on Evolution, p. 102.
186 STUDIES IN THE EVOLUTION OF ANIMALS

doubt that these two marks are inherited from the Wolf. When
in India, I examined a large number of very young Wolf-cubs,
which had their eyes still closed. They were usually of a dark
chocolate colour, and a large proportion of them had a white mark
on their chests, and a white tip to their tails. Probably in the
Wolf-cubs these are only vestiges—remnants, as I said—of a more
extended light-coloured under surface. For, as the Wolf-cubs grow,
the white becomes blended with the general fawn or tan colour of
the under surface, and eventually totally disappears, while the dark
colour of the back turns into an intimate mixture of black and tan
resembling that of certain Collies whose black upper surface had
changed into a mixture of black and tan.

As regards the white tip of the tail of certain mammals, there
are some curious phenomena connected with tips—tips of tails,
tips of ears, and tips of feet—which would point to some difference
in the innervation of tips. As I said, white and black are inter-
changeable. There are many mammals which have black tips to
their tails, and this, in allied or other individuals, may change to
white. The Arctic Hare in its summer clothing is brown, with black
tips to its ears ; and the ermine is also brown with half the tip end
of its tail black. When these two animals get their snow-white
winter clothing, the tips of the ears of the one, and the tip of the
tail of the other, remain d/ack ! I have seen a number of skins of
the Arctic Fox in the furriers’ shops, and many of them had a tuft
of black hairs on the tips of their tails. There are two coloured
pictures of the red common Fox in the Royal Natural History.
One has a black tip to its tail, and the other a white tip.

In this connection I would note a curious mark I have seen on
two sister Cats of the tabby variety ; (2) had pale tan hands and
feet, and on the hind limbs, from the heel to the toes, the dack sur-
face was black; while (4) had white hands and feet, and only a
INTERESTING FEATURES IN HORSES, ETC. 187

vestige of black near the heel. Not improbably this black surface
on the back part of the hind limbs, as I have already hinted, may
indicate that some ancestral form was plantigrade, and in changing
to a digitigrade descendant, a record was left of its ancestral
plantigradeness in this contrast of colour. I have seen the same
black mark on the hind legs of Collie Dogs ; and if the reader will
turn to the Serval of Fig. 17, he will see that the same surfaces are
black, which I take to be a colour-vestige of an ancestral plantigrade
surface. Then, curiously enough, we find that the hind edge of the
metatarsus of Tvagulus—a pigmy Chevrotain, allied to Pigs—is
naked and callous—a veritable plantar surface, without hair,
inherited from some plantigrade ancestor, not unlike a Pangolin,
whose soles are bare. In the evolution of digitigrade carnivora
and ruminants from plantigrade ancestors, with bare soles, this
surface became elevated above the ground, and in some became
hairy, hence the contrast of colour there in certain Cats, Dogs and
the Serval, while in the Zvagudus it remained dare.
IS NATURAL SELECTION THE SOLE FACTOR
IN THE COLORATION OF MAMMALS? -
‘If one wishes to realise the wonders of natural selection, he or she should go to the
Natural History Museum, in South Kensington, and inspect the Homopterous insect
called Flatoides dealbatus, and think how much decimation of generations it must have

required to make that insect’s wings zzdzsténgucshable from the Lichens on the bark
of trees.’
PART VII

IS NATURAL SELECTION THE SOLE FACTOR IN
THE COLORATION OF MAMMALS?

IN studying this intricate subject the reader should not mind a
little repetition, as it may be needed to emphasise certain points.

In searching for a cause of the spotting of certain mammals, it
is not sufficient to say, in a-vague way, that it has been brought
about by ‘natural selection, through which it was made to har-
monise with its surroundings,) for there are in existence certain
facts which do not seem in the least to admit of such an
explanation.

In the Science and Art Museum of Edinburgh, there is a speci-
men of the Great Armadillo (Priodontes maximus). Its abdomen
is studded with separate rosettes, composed of very minute plates ;
and here I would wish again to emphasise the fact that the hind
feet of this Armadillo are ungulate, in the fashion of those of the
Rhinoceros and American Tapir, and very different from its fore-
feet, which have long claws.

Curiously enough, the Peba Armadillo (Tatusza Pebé)? has no

1 Where the black and spotted Jaguars are common, they can hardly doth harmonise
with their surroundings. Dr. Wallace (Zravels on the Amazon, p. 317) says: ‘In
some localities the black Jaguar is unknown, while in others it is as abundant as the
ocellated variety.’ On the other hand Mr. Saunderson says that the black Leopard in
India, is confined to heavy forest tracts, while the ocellated variety frequents open

country and rocky localities.
2 Science and Art Museum, Edinburgh.
192 STUDIES IN THE EVOLUTION OF ANIMALS

plates proper on its abdominal surface, but, on its chest and
between its hind legs, it has the merest varnish of former scales.
They are not unlike in nature to the black dabs on the lips of
Serranus Gigas, after the scales of the latter have thinned out into
nothing. The spots on the middle part of the abdomen of this
Tatusia are less distinct.

Armour on the abdominal surface of the Armadillo would
evidently have been inconvenient to an animal that rolls itself up
into a ball, and shows its armoured back to the enemy. It seems
that the Tatusia lost its abdominal plates, because they had become
not only useless, but inconvenient, or perhaps from some other
cause ; it, however, retained their vestiges as spots. The alternative
supposition would be that the Tatusia took to rolling itself up,
when it began to lose the stiff plating on its abdominal surface,
while the dorsal armour divided itself into moveable sections, which
admitted of its rolling itself up.

However this may have been, it is clear that the Armadillo
descended from an ancestor which was armoured both dorsally and
ventrally, somewhat in the way shown in Fig. 73. It is stated
that certain Glyptodonts had an armour on their ventral side, which
suggests that of the Turtle.

The existing Crocodiles have retained their bony dorsal plating,
while the ventral armour is made up of hard horny plates. In the
Crocodile, each plate is surrounded by skin, and its movements are
much freer than could have been those of the Glyptodon.

I would now ask—what business has the Peba Armadillo with
spots on its under surface, supposing them to have been originated
by a simple process of natural selection? The spots on the
abdominal surface could in no sense harmonise with their surround-
ings, and so become protective, for, when this Armadillo is un-
folded, and moving about, its abdomen is close to the ground, and
FACTORS IN THE COLORATION OF ANIMALS 193

the spots hardly visible, while, when the animal is rolled up into a
ball, the spots are wholly zxviszdle,

In the case of Jaguars and Leopards, which are also spotted on
the abdomen, it might be argued that, as these animals may some-
times climb up trees, their abdominal surface, looked at from
below, would harmonise with the lights and shades of the foliage ;

 

FIG. 73.—One of the Crocodiles in the Zoological Gardens, from a photograph.

and in the case of a Tiger, which has a striped abdomen, we might
say that, if it were lying down among the long grass, in which it is
often found, its abdomen would also harmonise with the lights and
shades of the grass stems. But no such excuse can be found for
the spotting on the abdomen of the Armadillo, nevertheless the
spots on its lower surface are there!

To my mind they can only be explained as impressions—.

N
194 STUDIES IN THE EVOLUTION OF ANIMALS

vestiges—left on the skin by plates in some ancestor, in which
plating was useful there, such as in Ganoid fishes and other
animals, like the Crocodiles, which pass a part of their lives in
water.

Then we cannot say that the dappled Horse, and the Zebra,
and the Giraffe, climb up trees, and the one requires its spots,
and the other its stripes, to harmonise with its surroundings ;
yet they are abundantly spotted, or striped, on their abdominal
surfaces,

The spotting, and of course the striping is a derivation from it,
seems to be a survival on parts of the skin where once ancestral
plates were. To the evolutionary philosopher they are of great
importance, for they indicate a link between skin-g/ating, and skin-
spotting.

It may be interesting to note that the embryo Armadillo
(Tatusta hybrida), shows plates on its abdominal region also!

It would appear that through heredity, not only bones, muscles,
etc., are transmitted, but also skin impressions, as if they were
eternal photographs of former plating.

Mr. R. Le Gallienne has written :? ‘Nature ruthlessly tears up
her replicas age after age, but she is slow to destroy the plates.
Her lovely forms are all safely housed in her memory, and beauty
and goodness sleep securely in her heart, in spite of all the arrows
of death.’

In other words, applied to our subject, this would mean that
the forms and colorations of animals, when once established, are
slow in becoming altered; that although the individual is being
continually destroyed, the mould that produced it is more per-
manent than many think, and that provided the individual has

1 Professor Parker’s Mammalian Descent, p. 94.
* The Religion of a Literary Man, p. 50.
FACTORS IN THE COLORATION OF ANIMALS 195

had opportunities of leaving descendants, the original characters
will somehow sooner or later reappear.

Then, from the point of view of natural selection, there is no
good reason why there should be such a sharp contrast of pigments
on the flank of the black Buck, and many other animals; but, from
the point of view of a hereditary impression, there seems very good
reason why the pigments which picture the separation of the
formerly armoured and unarmoured surfaces should be contrasted.
It seems to represent the line of division which we now see be-
tween the back and abdomen of the Armadillo (Fig. 71), and of
some Pangolins. The white or dzfferently coloured abdomen would
then mean that the abdominal surface lost its armour, and may be
also its spotting, dong before its ancestral forms lost their carapace.

This theory of the origin of contrasted colours is based on the
early disappearance of armour from certain parts of the surface
while it continued to a later period on certain others; and the
contrast of pigments, when finally the armour wholly disappeared,
represents the two stages. It does not attempt to account for
every bit of colour, but only for those colorations which appear
to be formed on a flan.

To put this idea more clearly before the reader—The repetition
through ages of the nerve-centre action which resulted in the forma-
tion of dermal bone-rosettes, left, as it were, a memory in the nerve-
centre. This memory, when the dermal plates could no longer be
produced, externated itself by producing only pzcture-rosettes, as
we see them in the Jaguar. When even the memory of separate
rosettes had been effaced, it still continued to externate itself by
producing a contrasted pigmentation of ventral and dorsal surfaces ;
that is, of the sites of the ear/zer and the /ater loss of armour.

Among existing animals we have survivals of all the stages
that mammals have gone through in their evolution. We have
196 STUDIES IN THE EVOLUTION OF ANIMALS

animals which are armoured above and below; animals which
are armoured only above; animals which are spotted above and
below; animals which are spotted only above; others which are
darker above and lighter below, with modifications in other parts ;
and finally animals which have lost every trace of ancestral armour,
and have become self-coloured throughout.

All these changes on the surfaces, it would appear, have their
‘molecular equivalents’ in the nerve-centres ; and when modifica-
tions, from whatever cause, occur in these, their representatives
on the surface undergo a simultaneous modification.

What wonder is it that some sort of picture of bygone states
should now be produced, when we know that every sensory im-
pression leaves a record in the grey matter which we call memory?

Now how did natural selection come in, in the case of Jaguars
and Leopards? These carnivora are expert climbers and pass
a part of their life on trees. Their skin-rosetting harmonises
well with the surrounding lights and shades thrown by the foliage,
and so this curious coloration has been mazntained by natural
selection, and not sade by it, while in the case of the adult Puma
and Lion the same process may have selected away the picture-
rosettes.

Of course the surviving Leopards that frequented trees did
not go there because they ¢hought the lights and shades of the
leaves would protect them. They frequented trees for other
purposes, and found that ¢here they were protected—that is,
there they could secuxe prey more easily than on the plain or
among bushes; and so the Cats with these peculiar markings
have been preserved. However undeveloped the brain of a wild
or domestic animal may be, it knows very well where it can
get food easily.

To try to account for every bit of coloration in existing
FACTORS IN THE COLORATION OF ANIMALS 197

animals by ‘natural selection’ would be an idle task. No amount
of natural selection, for instance, would account for the fact of
so many mammals having ringed tails and plain bodies (see
Appendix E, Nos. 4, 7, 11, etc.); for we cannot for one moment
suppose that it was the ¢az alone that required protection! In
such cases we can only fall back on the supposition that, for
some reason unknown, the tail has been slower in losing the
modified rosettes than the body.

As happens with most theories, to pursue this one further
would entangle it in difficulties, as so many modifications in the
coloration of mammals have occurred since their ancestors wholly
lost their armour. It is only by an occasional survival here and
there that some sort of concatenation can be conjectured to link
the armoured stage of mammals with the existing stage, which
in most cases is totally different.

The upshot of this discussion is that we come to the con-
clusion that the rosettes of Leopards are the inherited zmprints
of armour-clad ancestors, and zot the result of natural selection
by slow and useful modifications ; and that their strange colora-
tion has been preserved by natural selection because it may have
harmonised with the surroundings that these animals frequented.
PROBABLE CAUSE OF THE LOSS OF THE
CALCAREOUS ARMOUR IN MAMMALS
‘During sudden changes in the home or feeding-ground of animals, the dilemma
has again and again been adaptation or extinction ; in many cases nothing short of
metamorphosis has saved them from death and kept them alive in famines.’

PaRKER’S Mammalian Descent, p. 18.
PART VIII

PROBABLE CAUSE. OF THE LOSS OF THE
CALCAREOUS ARMOUR IN MAMMALS

BEFORE entering into this discussion, it may serve some purpose
to go over some of the points discussed in the foregoing pages.

A glance at the three Figures 4 to 7 shows that the groups of
spots on the abdominal surfaces are much more altered than those
on the back and flank. This, in my opinion, as I have often
stated, has resulted from the abdominal armour having been got rid
of defore the dorsal armour, so that the abdominal rosettes had time
to alter before the dorsal pigment-rosettes had come into exist-
ence, because the dorsal region was still covered by a carapace.
In other words, the ventral spots of the Leopards are much more
ancient, and consequently more modified than the dorsal rosettes.

One might suppose the process of dispensing with armour-
plating was something after this fashion :—The remotest vertebrate
ancestor was plated top and bottom, like the Ganoid fishes and
the Crocodiles.

Mr. Alfred Russel Wallace! says that, in skinning the /acaré
—an Alligator six feet long—‘the scales of the belly could only
be cut by heavy blows with a hammer on a large knife,’ and that
he ‘was obliged to borrow a drill to make the holes to sew up the
skin,’ after stuffing it.

Then the complete rachitis of the skin occurred first on the

1 Travels on the Amazon (Rio Negro), p. 219.
202 STUDIES IN THE EVOLUTION OF ANIMALS

ventral surface, as the part least needing armour, especially in land
animals, and a type of mammal was reached which is now
represented by the surviving Armadillos and Pangolins.

When the armour disappeared from the ventral surface it left
behind the imprints of armour-rosettes in the shape of pigment-
rosettes and spots.

Later on, for some reason which I shall come to in a little
while, a type of animal was reached in which the dorsal armour
also began to dwindle. For instance, Thoracophorus and Mylodon
Darwinit had separate scutes or plates on their carapace, and
others, such as Carzoderma, had only vestiges of plates.

We see a similar diminution and scattering of dermal plates,
and probably from the same cause, in some Trygons and in
Echinorhinus spinosus among fishes.

This dermal rachitis was evidently progressive, and eventually
a stage was reached in which the whole armour disappeared,
leaving only imprints of its former bone-rosettes.

Thus we come to the armourless ancestral forms of the modern
Jaguar and Leopards, with only pzctures of scutes, with all their
modifications, as detailed in the foregoing pages.

Of course all this descent is a speculation, but it is founded on
the facts which I have endeavoured to place before the reader. I
need not add that all these changes did not occur in a day.

There are many minute and other forms of spotting and
striping among different classes of animals which cannot honestly
be said to be of any use whatever for individual protection,
although they may be of service for social ends, such as recognttion,
etc. Animals, whose minds are not so much engrossed by fashions
and the frivolities of society, may perhaps take far more notice. of
a few characteristic spots and stripes on their associates than my
friend the Lady-Fellow of the Zoological Society could do, who,
LOSS OF CALCAREOUS ARMOUR IN MAMMALS 203

although she had been to the ‘Zoo’ hundreds of times, yet had
never seen the spots on the Lions.

For some reason, spotting appears to endure longest on the legs,
and striping on the tail. The spots, stripes, and ring-tails of
animals are hieroglyphics which appear to have a profounder
meaning, as to the origin of those that bear them—and possibly
also to our own origin—than may have been suspected.

It is difficult to look upon the ringed tail as otherwise than
a remnant of a spotted or striped body. As there are numerous
animals, such as Racoons, Coatis, and. many others, which have
only this remaining vestige of a spotted ancestry, it will be seen
how many animals must have lost their body spotting.

Both for observation among animals in a state of nature, and
among those under domestication, and also for experiments in
cross-breeding, there is an almost unexplored field open to any one
who may be interested in evolutionary biology; I mean the
study of the changes which occur, from birth to old age, in the
markings of the skins of animals. The changes that occur in the
pigments of the skin are tell-tales, not only of the organic phases
that particular animal has descended through, but also of the
atomic changes in the nerve-centres which occur in the life of the
individual.

We come now to the discussion regarding the probable cause
of the loss of the calcareous armour in mammals.

In the evolutions and revolutions which have occurred among
organisms from the beginning of time, one might well ask what
has caused the loss of those unwieldy bony carapaces and shields,
which, in the case of the Glyptodon, as Professor Parker remarked,
‘looked as if made for eternity’?

Of course no one would suppose that plate-armour of that sort
was dispensed with all of a sudden, although it is conceivable that
204 STUDIES IN THE EVOLUTION OF ANIMALS

some monstrous form, wzthout plate-armour, may have occurred all
of a sudden, just as hairless animals have suddenly appeared.

In Chlamydophorus we have probably a curious illustration of a
transition form. The calcareous shield has disappeared, and air
has grown in its stead; and over this the horny covering of the
bony carapace still remains. By getting rid of the latter also we
would have the finished hairy mammal, with pigment-rosettes on
its hair to show its connection with carapaced animals.

But the reader might say this tiny Armadillo kas no spots on its
hairy coat, although it would seem to have recently lost its bony
shield. No one would expect the law of spotting to be so un-
changeable as not to admit of any deviation. Indeed, in some
forms of Lynx we have the back unspotted, while the abdomen is
spotted and the short tail ringed.

To return to our question then—What could have caused the
gradual disappearance of armour, such as we know to have existed
in many extinct mammals, which at one time appear to have been
very numerous? It is stated? that ‘the habitat of the Armadillos
extended from Mexico and Texas to Patagonia, and during the
Tertiary Period was inhabited by the Glyptodons—gigantic
Armadillos whose remains are found abundantly in the bone caves
of Brazil.’

It is evident to me that these armoured mammals lost their
armour gradually. Some had very thick bony plates, others thin ;
some had their scutes commissured, others had them separate ;
in others, finally, there were only vestiges of bony scutes.

This is what Palzontologists say,2 under the heading of Glyp-
todons: ‘Carapace has no movable bands, so that the animal
could not roll itself up;. . the carapace usually has its com-

1 Encyclopedia Britannica, vol. ii., 9th edition.
* Manual of Paleontology, Nicholson and Lydekker, vol. ii. p. 1292.
LOSS OF CALCAREOUS ARMOUR IN MAMMALS — 205

ponent scutes united by suture, but in one genus they are separate ;
the scutes are moreover usually ornamented with a sculpture which
varies in the different genera and species; but they may be plain
or tuberculated. There is usually a ventral buckler (never found
in the Armadillos), and the tail is enclosed in a complete bony
sheath.’ +

Then, at p. 1294—‘ Thoracophorus differs from all the foregoing
in having the scutes of the carapace separated from one another,
and thereby approximates to some of the A/egatheriide, in which
there were a number of small ossicles imbedded in the dermis of
the dorsal region. A similar condition prevails in Carioderma of
the Loup-Fork beds of Texas,’

Further, at p. 1299—‘The Patagonian Jylodon Darwinii
(Gryptothertum) has numerous small dermal scutes, which do not
articulate with one another.’

From this it becomes evident that the group of mammals with
scutes or plates on their skin (Glyptodontide and Megatheriid@)
was not only a very large one, but it shows that the loss of plate
armour, in some, was gradual. The plates or scutes dwindled into
separate bony vestiges imbedded in the skin.

Now, to endeavour to answer the question I have put, I can
only venture on the following speculation :—

To account for such accumulations of coal as are known to
exist, physicists have supposed that at one period of the earth’s
history there must have been vastly more carbon dioxide (CO?)
in the atmosphere, in order to furnish the carbon which such
prodigious vegetation must have needed.

Sir Robert Ball has informed us that the clouds of- the

1 In the Manchester Museum there is a Lizard without a name. It is ticketed ‘a
Lacerta from Lower Egypt.’ Its great peculiarity is the tail, which is enclosed in
spiked rings, almost exactly like a miniature tail of a Glyptodon. The rest of the body
is covered with very minute scales.
206 STUDIES IN THE EVOLUTION OF ANIMALS

,

photosphere of the sun are no other than pure incandescent carbon.
Owing to the intense heat, the carbon is dissevered from all its
possible combinations and shines and radiates heat as the coal in
our grate does, or as the carbon filament in the electric lamp does.

It is logical therefore to infer that our earth had, at one time,
a vast deal of this same material in its atmosphere. Then, as it
cooled down, the carbon began again to combine with oxygen ! to
form CO? If this be so, it would follow that at one time our
atmosphere was choked with CO%, and all life, as we now know it,
must have been impossible till the evolution of low forms of plants
undertook to liberate the oxygen and hoard up the carbon in the
plant tissues.

Now a large quantity of CO? in the air would also mean a
large quantity of CO? absorbed by the water. And this again
would mean a large quantity of carbonate of dime in solution in the
water. Hence we find all the lower forms of primitive life, even
down to seaweeds, mostly encased in calcareous material, forming
more or less thick shells of innumerable forms, carapaces, exo-
skeletons, etc.

It is only necessary to think of the chalk and other limestone
rocks,—which are formed of countless myriads of foraminiferous
shells,—and of the coral rocks, to have some idea of the vast amount
of carbonate of lime which has been withdrawn from the waters of
our earth; for these minute animals and corals could have got
the lime they needed only from the lime salts in solution in water.
Moreover, the fauna of the seas could obtain the materials of both
their inner and outer skeletons only from the same source.

The abstraction of carbon from the atmosphere, and the hoard-
ing of it in coal measures, and the abstraction of the same carbon,
in the shape of carbonate of lime, from the waters, and the hoarding

1 Oxygen may not have been detected in the sun, but we Aave it in our atmosphere.
LOSS OF CALCAREOUS ARMOUR IN MAMMALS — 207

of it in lime rocks, must have, in course of time, caused something
like a Zéme famine in the process of multiplication of animals, hence
the nudity of a number of animals whose ancestors at one time must
have been more or less encased in calcareous armour.

Lime salts must have been abundant everywhere, not only in
water plants and animals, but also in land plants and animals.
Lime was largely needed not only for building up of the exo-
skeletons, but also for building up the evdo-skeletons of those
extinct monsters, the thigh-bone of some of which was taller
than a six-foot man, and proportionately massive.

It is therefore not to be wondered at that animals, multiplying
indefinitely, may have eventually reached a period in which there
was an znsufficient supply of lime to supply all demands.

The endo-skeleton, if not sufficiently supplied with lime, would
become rachitzc. The animal with a soft endo-skeleton would
collapse, and be of no use in the battle of life. So it was the
exo-skeleton that had to dispense with the calcareous stiffening,
and the animal world may then have begun to experience the
pathological phenomenon of animals with a rachztic skin |—cer-
tainly. a great advantage where activity had become a factor in
the struggle for life.

Even when land mammals had lost their exo-skeleton, they
must have continued to use up incredible amounts of carbonate
of lime for building up their endo-skeletons ; and when we read of
the swarms of ruminants which blackened the plains of Africa
and North America, we begin to realise the amount of this lime
salt that must have been hoarded in their endo-skeletons, But
this salt of lime such countless ruminants could evidently obtain
in sufficient quantity from the grasses and trees on which they
fed.

And this very carbonate of lime which nourished the grasses
208 STUDIES IN THE EVOLUTION OF ANIMALS

and trees was obtained from the disintegration of the minute
shell covering of myriads and myriads of far remoter ancestors.
These shell coverings had been hoarded ages ago in the rocks,
or on the debris of rocks on which those grasses and trees grew |

In the Royal Natural History, vol, ii. p. 193, it is written that,
‘of all the quadrupeds that have ever lived upon the earth,
probably no other species has ever marshalled such innumerable
hosts as those of the American Bison. It would have been as
easy to count or to estimate the number of leaves in a forest
as to calculate the number of Bison living at any given time
during the history of the species previous to 1870... As
an instance of these enormous numbers, it appears that, in
the early part of the year 1871, Colonel Dodge, when passing
through the great herd on the Arkansas, and reckoning that
there were some fifteen or twenty individuals to the acre, states,
from his own observation, that it was not less than 25 miles
wide and 50 miles deep, and was reckoned to consist of not
less than four millions. ‘Many writers, at and about the date
mentioned, speak of the plains being absolutely black with Bison
as far as the eye could reach.” It is even stated that trains were
sometimes derailed on the Kansas Pacific Railway when attempt-
ing to plough their way through these crowds of Bison.

The reckless destruction of these useful animals, for the sake
of their fine skins, has left little more than ‘huge stacks of skulls
piled up at many of the railway stations awaiting transport,’
perhaps to make bone-black for refining sugar. Such is the
irony of nature!

Mr. Hutchinson, quoting from Darwin, on the American
continent, says—‘ Formerly it must have swarmed with great
monsters ; now we find mere pigmies compared with the antecedent

1 Creatures of Other Days, p. 248.
LOSS OF CALCAREOUS ARMOUR IN MAMMALS 209

allied races. If Buffon had known of the gigantic Sloth and
Armadillo-like animals, and of the lost Pachydermata, he might
have said with greater semblance of truth that the creative force
in America had lost its power rather than it had never possessed
great vigour.’

What is the reason of this change from the monstrous-sized
animals of the past to their modern pigmy descendants? With-
out carbonate of lime, neither the external nor the internal
skeletons can be built up. The same cause—want of sufficient
carbonate of lime in the waters, plants, etc—that caused the
rachitis of the dermal skeleton, prevented the internal skeleton
from attaining a great size; hence the pigmy animals of ¢hese
days, as compared with the monsters of those days. But let us
not fancy that it was to the disadvantage of the former. It pro-
duced greater activity in the carnivora, and greater fleetness in
the herbivora; and so these have survived, and the ancient un-
wieldy ones have perished.

Some naturalists seem to think that, as animals became more
active, they lost their plate-armour by natural selection, the more
active killing out the less active armour-plated animals. But I
think that just the reverse may have occurred. Animals became
active decause they began to acquire rachitic skins, owing to a
lime-famine, this material having been used up mainly in making
rocks! The deficiency of lime in the exo-skeleton may have not
only brought about more activity in the animal, but deficiency
of the same material in the endo-skeleton may have also brought
about smaller animals; so that the two deficiencies may have
gradually contributed to create a much more active race of animals
than there had been before.

It is not difficult to imagine that, although in some instances
the huge dish-cover carapace of an animal like the Glyptodon

oO
210 STUDIES IN THE EVOLUTION OF ANIMALS

may have been a good protection, if the animal squatted and
hid himself under his huge dish-cover; in other instances, how-
ever, this same protection might have become a source of great
weakness. Let us suppose that the Glyptodont, as is likely, was
sometimes wholly unarmoured on his abdominal surface, like
many of the existing Armadillos, Then if his more active enemies
had learnt to upset him, and leave him kicking in the air like
an overturned Turtle, he would be wholly at their mercy, and they
might eat his underside, and scoop him out at leisure, in spite
of his formidable dorsal protection. We need not even suppose
that each of his enemies required to have great strength, for we
know that several Grampuses attack a Whale at the same time
and kill it, and that Wolves co-operate in their attacks on large
animals.

Such is a speculative sketch of the physical conditions which
possibly may have brought about the existing active and smaller
races of animals. Briefly, the hugeness of the endo- and exo-
skeletons of those ancient extinct monsters may have been due to
excess of lime in their food.

I have called the absence of lime-stiffening in the exo-skeleton
a vachitic skin. It is not unlike a rachitic egg-skin, when the hen is
unable to obtain lime salts for building up the egg-shell. In the
latter case, the deficiency is a great disadvantage, but in the former
an elastic and flexible skin, giving freedom to the movements of
the muscles and endo-skeleton, would have been a great advan-
tage.

Concurrently with the loss of armour, and with the development
of muscular activity, there must have been evolved a larger and more
complicated brain. Those huge monsters of ancient times are
known to have had tiny brains, in proportion to their prodigious size.
The spinal cord no doubt supplemented the small size of the
LOSS OF CALCAREOUS ARMOUR IN MAMMALS - arr

cranial brain, and in some cases, as in the Stegosaurus, there is
reason to believe that an additional lumbar brain existed, as a part
of the spinal cord.

I think I have said enough to indicate by what possible causes
the plate-armour of ancient animals may have been got rid of, and
therefore shall not follow up this speculation any further.

The upshot has been that the ancestors of the Jaguar and Leo-
pard, from a similar lime-famine, lost their calcareous carapace,
which consisted of done-rosettes, and so their descendants have
had to be satisfied, with profit to themselves, with rosette stamps
instead !

I believe that all mammals, including marsupials, descended
from armoured ancestors, and that a famine of lime by degrees
relieved them of the calcareous armour, but left on their skins the
stamp of the armour-plates, and, in some cases, that of the carapace
asa whole. By slow degrees these also became modified in various
ways, and even wholly obliterated. The least altered from the
originals, after the armour wholly disappeared, is the Jaguar skin ;
then the others follow somewhat in this order: Leopards slightly
altered ; spotted and dappled mammals of all degrees and kinds ;
more or less altered striped mammals ; piebald mammals ; mammals
with self-coloured bodies, but with ringed tails ; and lastly, mammals
self-coloured all over.
RELATIONSHIP BETWEEN.THE ARMADILLO
THE RHINOCEROS, THE HORSE, THE
GIRAFFE, AND THE ZEBU
‘Myriads of types, unready and conservative, have passed out of being; that which
they had, but did not improve, has been taken from them, whilst others, by steady
improvement of what they had, have had more and more life given to them. But not
always by slow, steady increment ‘‘ during long ages,” has the advance been made.
Nature does, now and then, make amazing leaps, certain types taking on sudden
metamorphosis, and, in the fraction of a lifetime, the low is transformed into the high.’

Professor W. KITCHEN PARKER, Ov Mammalian Descent, p. 93-
PART IX

RELATIONSHIP BETWEEN THE ARMADILLO, THE RHINO-
CEROS, THE HORSE, THE GIRAFFE, AND THE ZEBU

IN order that we may be able to decipher more fully the hiero-
glyphics so profusely scattered on the exterior surface of the
domestic Horses, we have to study the exterior of the various
species of Rhinoceros a little in detail.

Zoologists admit, if I interpret their writings correctly, that
the Horse is not only allied to the Rhinoceros, but that very
probably the Horse’s one digit has descended from the enlarged
middle or third digit of some Rhinocero-Tapiroid ancestor.

Then ‘the crowns of the lower true molars consist in their simplest
structure of two transverse ridges (as in the Tapir), but these ridges
may be curved into crescents (as in the Rhinoceros), or complicated.
by foldings and convolutions (as in the Horse). The transition
from the simplest brachydont (or short-toothed), to the most
specialised hypsodont dentition (or tall-toothed) is accompanied by
a reduction of the number of the digits from four or three to one;
that one being the third or middle of the typical series of five}

If we direct our attention to the hide of the Indian Rhinoceros:
we seem to feel a sort of conviction that the scapular and pelvic
hide-shields of this huge mammal are homologous with the bony
scapular and pelvic shields of the Armadillos. We seem to feel also

1 Manual of Paleontology, by Nicholson and Lydekker, p. 1353.
216 STUDIES IN THE EVOLUTION OF ANIMALS

that the ears of the Rhinoceros and the Armadillo are singularly
alike. Then if we turn to fossils, we find that the Polacanthus has
a bony pelvic shield rising in knobs,! not unlike those of the hide-
shields of the Indian Rhinoceros (Fig. 77). This is what Nicholson
and Lydekker say of it (p. 1161): ‘In Polacanthus of the same
(Wealden) beds, we have a remarkable form (of Dinosaur), in which
the dermal armour constitutes a complete solid carapace over the

 

Fic. 77.—Indian Rhinoceros (2. Unicornis), from a photograph, F. G. O. 8. 20046.

whole of the dorsal aspect of the lumbar region, some of the com-
ponent scutes being tuberculated, and others ridged; while there
was also a number. of detached flattened spines somewhat like
those of Hyzosaurus, which probably formed a line in the dorsal
region. This peculiar type of carapace forcibly recalls that of the
Glyptodont edentates,’

In order to emphasise the similarity of the Rhinoceros and the

1 See Fig. 63 (a).
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS 217

Armadillo, I would here mention two other interesting points. The
Giant Armadillo (Prionodon Maximus) has its hind feet ungulate :
its hoofs are almost exactly like those of the Malayan Tapir; and
in some Rhinoceroses the incisor teeth are wholly wanting,
and that part of the jaw is contracted, not unlike that of the
Glyptodon.

Then there is a type of Rhinoceros which brings us still more
closely to the Armadillo type. This is what Mr. W. T. Blanford?
says of the RAznoceros Sondatcus, the smaller one-horned Rhino-
ceros which has been observed at great elevations in Burmah:
‘Skin naked, or nearly so, not tubercular, the epidermis divided
by cracks into small polygonal, sub-equal scale-like discs through-
out the body and limbs. Surface of the body divided into shields
by folds, as in R. Unccornis, but the fold in front of the shoulders
is continuous across the back, like that behind the shoulders and
that in front of the thighs.’

That is to say, unlike the Indian Rhinoceros, the divisions of the
plated hide of this Javan Rhinoceros go right over the back exactly
like the divisions of the carapace of an Armadillo. So that between
the type of the Glyptodon and the type of the existing Armadillo
there must have been some intermediate type approaching that of
the R. Sondaicus, in which the armour still consisted of Jone-rosettes,
somewhat like those of the Glyptodon, but the whole carapace
admitted of a freer movement, because it was divided into three
or four separate sections attached to each other by simple un-
armoured skin, acting as leather hinges, and the Rhzxoceros
Sondaicus may be the descendant of this intermediate type of
Armadillo.

Now in the Natural History Museum there is a small Rhinoceros
without a ticket (at least the ticket is not visible) about the size of

1 Fauna of British India, ‘Mammalia,’ p. 474.
218 STUDIES IN THE EVOLUTION OF ANIMALS

a Newfoundland Dog. The specimen is hidden by the larger ones,
and jammed in among them, so that it is not easy to examine it
thoroughly. It has no horns, or perhaps only a rudimentary one
on its nose. It may be a young one of R. Sondaicus(?) Of
whatever species it may be, it presents quite a revelation as to the
points I am discussing. It has the scapular and pelvic shields
somewhat like those of the Indian Rhinoceros (R. Unicornis), but
the whole surface is covered with small plates, which vary as to
their component platelets.

In Fig. 78 I have given two variants taken from the posterior
aspect of the left haunch of this Rhinoceros. Its plates appear to
be of some dony substance.

a b Cc

 

Fic. 78.—(a) and (4) Bony plates from haunch of small Rhinoceros, Natural History
Museum (2. Suxdaicus?); (c) bony plate of Tolypentes tricincta (an Armadillo).

This is not all, for in one or two places the plates have fallen
off, showing that they are something quite distinct from the
dermal tissue proper ; and what may perhaps be of some import-
ance, the detachment of the plates has left an zmpression of their
component platelets on the subjacent skin.

Some of the plates of this little Rhinoceros, like (a), do not
differ materially, although they do in outline, from those of one of
the Armadillos (Tolypentes tricincta), shown in (c). Then (4) in
its component platelets is not unlike a Jaguar rosette.

+ Tts position has been recently altered.
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS 219

The curious part is that the tail of this Rhinoceros is also
covered with similar plates disposed ring-fashion like those of the
tail of an Armadillo.

Here then we have a Rhinoceros encased in armour, almost
exactly in essence like that of an Armadillo.

A glance at the other species of Rhinoceros in the Natural
History Museum teaches us something more in our endeavour
to discover further evidence of the relationship of these mammals
and the Horse. For R. Unicornis (India) has the skin covered
with Azde tubercles only, without any deposit of bone-plates,
admitting of a freer movement. R. Sumatrensis (two-horned) is
the smallest and the most hairy, the skin being only rough and
granular with the folds of skin less marked. It is evidently a type
which has passed from the plated to the smooth and hairy mammal.
This also is met with at a high elevation (4000 feet). There are
variations of the Sumatran Rhinoceros from Chittagong and
Malacca, which have a still smoother skin and longer hair. We
come ultimately to the African species, which have neither plates,
nor folds, nor hair of consequence, and their skin is nearly as smooth
as that of a Porpoise, making allowance for the difference of the
medium in which these two kinds of animals live.

Then in Fig. 79 I have given what appears to me a variation of
Rhinoceros Sondaicus. It is not only covered with small plates,
from head to foot, but it has a curious, and, may be, instructive
variation of plating on its flank. About this I have something to
say in another place. In the meantime, in Fig. 80 I give four
groups of plates, picked out from what I suppose to be a &.
Sondaicus (Fig. 79). These groups are not unlike the rosettes
of the Armadillo of Fig. 78 (c).

It will be seen that the Indian Rhinoceros of Fig. 77, although
it has lost its bone-rosettes, has retained hide-knobs, disposed.
220 STUDIES IN THE EVOLUTION OF ANIMALS

as shown in Fig. 81. (d@) is a group of spots from the shoulder of a
Horse, given here for comparison.

 

 

 

Fic. 80.— Plates picked out of the Rhinoceros of Fig. 79. (a) and (4) from middle of flank ;
(c) from hind margin of scapular-shield; (¢) from hind margin of neck-shield.

The hide-knobs of the Indian Rhinoceros shown in Fig. 81 are

represented as seen from a certain distance on the animals of the
Zoological Gardens,
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS 221

Some of the stuffed Rhinoceroses of the Natural History
Museum are so placed that it is impossible to get near enough to
them to examine their hide in detail. In the Edinburgh Museum
of Science and Art, however, I had a rare opportunity of

he x e a a
© Be
56 SG. Wi. cae
CG. me oc v @

Fic. 81.—(a) and (4) are from the shoulder and hip of an Indian Rhinoceros; (c) from the
hip of another individual of the same species (Zoological Gardens); (d) is a group of black

spots seen on the shoulder of a Horse; (e) hide-plate from Hairy Rhinoceros of Chittagong
(Zoological Gardens).

S oS
S Sf XO
Cra. 99 in a
029
a NL
©

 

Fic. 82,—(a) From the lower and back part of the scapular shield; (4) from the back
part of the pelvic shield, of an Indian Rhinoceros (Edinburgh Museum of Science and Art)
—reduced.

minutely examining the hide-shields of an Indian Rhinoceros
(R. Unicorns). .

From Fig. 82 it will be seen that the hide-knobs of this animal
resolve themselves into patterns almost identical with the armour
bone-plates of the Sturgeon and the Crocodile shown in Fig. 68
(6) and (c), and of the Glyptodon shown in Fig. 61 (g).
222 STUDIES IN THE EVOLUTION OF ANIMALS

The central portion of these rosettes is a pyramidal hide-knob,
composed of smaller sections, and surrounded by the usual ring of
small tubercles. Compare these with the Horse rosettes of Fig. 56 (a).

The similarity of pattern between the hide-knobs of this
Rhinoceros and the bone-rosettes of the Glyptodonts and Arma-
dillos is astonishing, and leaves little doubt in one’s mind that the
Indian Rhinoceros, with its scapular and pelvic shields and its
hide-armour, comes down to us from some Armadilloid ancestor.

In the Horse, every trace of plate and tubercle has disappeared,
but they have left instead their indelible pigment-pictures in some
varieties of the dappled Horse, as shown in Fig. 56 (a), (4) and (¢).

We have now to examine a very interesting feature of the R.
Sondatcus given in Fig. 79. Its flanks look as if they were cracked
into larger plates than those of the rest of the body. They may be
in fact fuszons of a number of the smaller plates—for although the
plates of this Rhinoceros are of a bone-like nature, they may be
quite capable of fusion as shown in the hide-plate of the Chittagong
Rhinoceros (Fig. 81 (e)).

It would at first seem improbable that stiff bone-rosettes are
capable of fusing into larger plates; but we have already seen an
approach to fusion of bone-rosettes in the armour of both the
Glyptodon and the Leathery Turtle (Figs, 67 (2) and 68 (a)).

This cracked appearance of the hide of KR. Sondaicus of Fig. 79
forcibly recalls, it seems to me, that flank reticulation which is so
common a feature in the dappled Horse (see Figs. 34 and 38). And
in -both animals it may mean the same thing, viz.,in the Rhino-
ceros the fusion of one or more éone-rosettes, and in the Horse the
fusion of one or more fzcture-rosettes. If this be conceded, we
come to the same conclusion which has been reached frequently
before, viz., that both the Rhinoceros and the Horse have descended
from some Glyptodontoid ancestor.
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS = 223

Of course Glyptodontoid and Armadilloid animals vary in their
bone-plating, as much as Rhinoceroses vary in their hide-plating ; so
do Horses and other mammals vary still more extensively in their
picture-plating.

In some species of Rhinoceros the shields and plates have
entirely disappeared. Having got rid of the plates, some of the
species got rid also of the hide-shields. Natural selection was
evidently rendering their skin more pliable, in order that their
movements might be freer. In other words, their movements
became freer as they were relieved of their thick hide-plates and
shields. Not improbably the African species, as a compensation
for their loss of armour, may have obtained those formidable horns
which we see in the Natural History Museum.

In the dappled Horse the pigment arrangements have been so
modified in most cases, as hardly to maintain any resemblance to
the typical rosetting of the Jaguar. In only a few cases have I
succeeded in tracing true rosettes in the Horse, and these I have
shown in Fig. 56. Usually it is hopeless to trace any minute rosette
resemblance in the Horse dappling. But by observing an infinite
number of all colours, and putting two and two together, one may
succeed in evolving an ideal of what some remote ancestor of the
Horse may have looked like. Anyhow, the Zebras are clear evi-
dence that, whatever the external disposition of pigments may
originally have been, the resulting modification has been almost
identical with that of the Tiger. In this, and much more clearly
in other Cats, it is easy to prove to one’s-self that stripes and.
bands originated from rosettes like those of the Jaguar and
Leopard.

Then in striped animals themselves we seem to witness modifi-
cations undergoing before our eyes, so to speak. In Grevy’s Zebra
the bands are very numerous and narrow, some of. them coalescing
224 STUDIES IN THE EVOLUTION OF ANIMALS

into oze band; while in Burchell’s Zebra every alternate band has
become fainter, and may be disappearing altogether.

I have so far endeavoured to trace the relationship of the Arma-
dillo, the Rhinoceros, and the Horse, simply from characters which
they retain on their hides. This relationship I find can be also
traced to the Zebu of Fig. 58, and to the Giraffe of Fig. 57. In
another place I have shown that probably there is a more intimate
relationship between the Horse and the ruminants than there is
between the Horse and the Rhinoceros. Of course their skeleton
and general anatomy sufficiently indicate a certain fundamental
relationship, but what I am aiming at here is to trace a closer
relationship between certain groups of mammals by means of
the hieroglyphics exhibited on their skin. With these external
and more transient characters anatomy does not concern itself.

If the reader will take the trouble to compare certain Horse
rosettes shown in Fig. 43, certain Giraffe rosettes shown in Fig. 83
(a) and (4), and the rosettes of the Zebu of Fig. 83 (¢) and (2), with
certain Jaguar rosettes of Fig. 59, and then again compare certain
bone-rosettes of Armadillos of Fig. 63 (c) with certain hide-rosettes
of the Rhinoceros of Fig. 80, he can hardly fail to be convinced that
they a//—bone-rosettes, hide-rosettes, and pigment-rosettes—had one
and the saime origin. Of course the rosettes of the Horse, and more
especially those of the Ox, have undergone much alteration, not only
through remoteness of descent, but also by prolonged domestica-
tion, and human selection, so that piebaldness and total oblitera-
tion of all traces of rosetting are very frequent features in these
animals.

From what evidence I have been able to adduce, I think we are
justified in again drawing the broad conclusion that, in mammals
at least, all spotted, striped, ringtailed, and piebald animals have
descended from armour-plated ancestors. And as we know that
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS _ 225

both among wild and domesticated mammals a number of self-
coloured varieties are indubitably related to either spotted or striped
congeners, we reach again a still broader conclusion that very pro-
bably a7 mammals, zncluding the marsupials, have descended from
armour-plated ancestors,

Having once surmised that the reticulations we see on the

c ad

Fic. 83.—(a) Rosette from lower part of right haunch of Giraffe; (J) rosette from right
shoulder of the same (Natural History Museum); (c) rosette from upper part of fore-leg of
Zebu; (d) rosette from shoulder of the same (see Fig. 58).

dappled Horse’s flank may be zprznts of the commissures between
the plates which we see on the flank of Rhinoceros Sondaicus of
Fig. 79, something further is suggested.

In Fig. 40 I have shown that the commissure-pictures coincide
with the network of superficial veins on the Horse’s flank. Not
improbably these superficial veins are the ancestral commdssure-
veins ; that is, a network of veins of a certain size located in the

P
226 STUDIES IN THE EVOLUTION OF ANIMALS

clefts of the plate-commissures, into which the blood supplied to the
plates found its way much as the intra-lobular veins of the liver
receive the blood from the veinlets of the lobes. Whether this be
so or not may perhaps one day be ascertained by dissection of the
skin of the Rhinoceros, and also of the skin of the Armadillo. It
might thus be easily ascertained whether the commissures of the
plates have any corresponding veins.

That the superficial veins of the Horse, or their nervous
apparatus, play some part in the distribution of pigments seems
likely. The ungulate character of the Horse’s hands and feet
would naturally lead one to surmise a close relationship between
this animal and the Rhinoceros, but we should not forget that the
Great Armadillo on its hind feet has Avofs, and not claws Both
the Horse and the Rhinoceros furnish indications of descent from
carapaced ancestors, but the question is whether the Horse came
to be what it is through the ruminant branch, or through some
Rhinocerotoid branch of ancestors. In another place I have shown
that there is reason to believe that the Horse and the ruminants
are closely allied. From features that I have indicated in the 2.
Sondaicus, especially in his astonishing tail, encased in rings of
bone-plates, there can be no reasonable doubt that 4e, at all events,
descended from armour-plated ancestors.

The degradation from bone-armour to picture-armour might at
first sight appear a great disadvantage for subsequent races, but in
reality it has resulted in giving natural selection a totally different
direction. It has resulted in the evolution of fleetness in the
Horse, Antelopes, and Deer, and in the astonishing springs of the
carnivora that feed on them. In other words, it has resulted in the
development of great muscular and brain power—with a suitable

1 See also p. 132, AZammalian Descent, by Professor Parker, about ‘ ungulate
Lemurs.’
RELATIONSHIP OF ARMADILLO TO OTHER MAMMALS 227

framework of bone—the lines on which the animal world was ¢here-
after to be ruled.

It would be idle to suppose that the bony-plates of the Arma-
dillo, the hide-plates of the Rhinoceros, and the picture-plates of
the Horse, are all so like each other by mere accident, any more
than we can consider that the seven cervical vertebre of these
animals came to them all by accident. One can fully understand
that the external features of an animal are subject to much greater
variations than the internal skeleton; nevertheless, in spite of all
the modifications in the skin, which the animal unconsciously
brought about in order to adapt itself to its surroundings, enough
is left in the skin features of many species to assure us that all
these animals have had a common origin, and that they descended
from an armour-clad ancestry. The evidence of the pictures on the
skin of the Jaguar, as I have shown, is too clear to admit of any
other interpretation than that of descent from armour-plating.

I have said enough to prove that the markings on the skins of
mammals are not necessarily the result of natural selection, work-
ing gradually on some incipient variation through long periods of
time; but more probably the result of an zxherited nerve-centre
habit. Then, after the total disappearance of calcareous matter
from the skin, this habit continued its action on the pigments of
the skin, and was modified subsequently in a hundred ways.
What natural selection probably did do was, as I said, to mazntain
this inherited skin feature, wherever it was advantageous to the
animal, and to obliterate it wherever it was not.

From all this wearisome discussion we learn one great lesson,
and it is this :—that habits, or memories, of the nervous system,
when established for long ages, are got rid of very slowly ; and that
it requires more long ages for mew ones to become established in
their places,
EXPLANATION OF THE CALLOSITIES ON
THE. LEGS OF EQUINE ANIMALS
AND OTHERS
“We find heredity, or adherence to a general type derived from ancestors, opposed by
special modifications of or deviations from that type, and the latter generally getting the
victory, although in the numerous rudimentary structures that remain there is significant
evidence of ancestral conditions long passed away.’

The Horse, by Sir W. FLOWER, p. 3.
PART X

EXPLANATION OF THE CALLOSITIES ON THE
LEGS OF EQUINE ANIMALS AND OTHERS

ONE of the features which distinguish the Horse from the Ass is the
presence of callosities on the inner aspect of a// four legs in the
Horse, while inthe Ass and Zebra these callosities are present only
on the fore-legs. In the Horse, on the fore-legs, they are above the
wrists (commonly called knees); and on the hind-legs, they are
below the heels (commonly called hocks).

One day, at the sea-side, I was examining some little Donkeys
which had stripes on their legs. I asked the Donkey-boy, ‘What
are those things on the inside of the Donkey’s fore-legs?’ He said,
‘J don’t know, I will go and ask’; he added, ‘but I can tell you
what that mark on the Donkey’s back is.’ ‘What is it?’ I said.
He replied, ‘When Jesus Christ went to Jerusalem he rode a
Donkey, and after that it had the sign of the cross on its back.’ I
suppose he inferred that his little Donkey was a descendant of ¢haz.
The event of the entrance into Jerusalem, be it remembered, must
have been a good bit before the Crucifixion!

A well-dressed man who was standing by and heard our con-
versation said—‘ Every gentleman knows what those things are on
the Donkey’s fore-legs. They are corns.’ ‘But,’ said I, ‘they are
very different from our corns.’ ‘Yes,’ he observed, ‘the corns of
Horses and Donkeys are different.’
232 STUDIES IN THE EVOLUTION OF ANIMALS

Stable-men call them corns. Professor Flower calls them
warts or callosities, or ‘chestnuts,’ and ‘mallenders,’ and ‘sallenders,’
as some old books designate them.

He says—‘ There the skin is peculiarly modified from its usual
structure. No hair grows on these patches; ‘the papilla of the
derm or true skin are much enlarged, and covered with an abundant
and thick epidermis, which becomes dry and horny, and some-
times (in the Horse) accumulates in considerable quantity on the
surface, occasionally even making a horn-like projection.’

Professor Flower! adds— The signification and utility of these
structures are complete puzzles ;’ and on p. 173, ‘ They obviously
belong to a numerous class of special modifications of particular
parts of the cutaneous surface which occur in very many animals,
the use of which is in most cases remarkably obscure. Bare spots,
thickened patches or callosities, and tufts of elongated hair, often
associated with groups of peculiar glands, are very common on
various parts of the body, but especially the limbs, of many
ungulates, and to this category the “chestnuts” of the Horse
undoubtedly belong.’

Then, in a note to the same page, he says—‘ Dr. J. E. Gray
divided the pigmy Chevrotains (ruminants allied to Pigs) into two
groups—Memznna, ‘ with a naked prominence on the outer side of
metatarsus, rather below the hock, and Z7vragulus, ‘with hinder
edge of the metatarsus naked and callous.’ ?

Professor Flower concludes this part of his book thus: ‘If they
(the corns) teach us nothing else, they afford a valuable lesson as
to our ignorance, for if we cannot guess at the meaning or use of a
structure so conspicuous to observation, and in animals whose

1 The Horse, p. 172.
2 At the end of Part v1. I made a suggestion which may give a different meaning
to the callosity of Tragulus.
CALLOSITIES OF EQUINE ANIMALS AND OTHERS 233

mode of life more than any other we have had the fullest oppor-
tunity of becoming intimately acquainted with, how can we be
expected to account off-hand for the endless strange variations of
form and structure of animals of whose habits and methods of
existence we know absolutely nothing ?’

I had pondered over the callosities of the Horse, Ass, and

( a

  

<e@

Fic. 84.—(a) Callosity on fore-leg of Tibetan wild Ass or ‘Kiang’ (Zguus hemionus) ;
(2) callosity on inner aspect of hind-leg of the ‘ Alpaca’ (Lama pacos); (c) tuft of dark hair on
light ground of leg of the ‘ Vicugna’ (Lama vicugna) ; all three from Natural History Museum.

Zebra a good bit before I read the foregoing in Sir W. Flower’s
book on The Horse.

Fig. 84 (a) shows the callosity on the fore-leg of the Tibetan
wild Ass; and Fig. 53 shows it on the fore-leg of the Zebra.

I have never met with an Ass which had callosities on its hind-
legs. In the stables of the Great Northern Railway Company I
have seen a Horse which had xo callosities on the hind-legs; and
234 STUDIES IN THE EVOLUTION OF ANIMALS

another which had them as small as peas on those limbs; and
the foreman of the stables of the London Road Car Co. told me
he has seen them as small as the nail of his little finger. It is
therefore not improbable that the ancestors of the Ass and Zebra
may have had callosities also on the hind-legs, but from some

 

\

4,

“hy
Ms
pn ae
Ze ,
CP

Fic, 85.—(a) Black tuft of hair on fawn-grey—hind-leg of Peruvian Roebuck (Coriacus
antisiensis); (6) dark brown tuft on a dirty white ground—hind leg of Elk ; (¢) grey tuft on
fawn-coloured leg—hock of Virginian Deer (Cortacus Virginianus)—from Natural History
Museum,

cause they may have dwindled off and disappeared so completely
from those species that they are not reverted to. As far as I am
aware, if the Ass and Zebra ever had them on their hind-legs, no
trace of them is to be seen there now.

1 It is curious that Agus Grevy? of Fig. 52 does not show a. callosity on the fore-leg
as in Fig. 53. Grevy’s Zebra which I saw at Tring also has its fore-legs wzthout them.
CALLOSITIES OF EQUINE ANIMALS AND OTHERS 235

In the domestic Horse they vary in shape. In the fore-legs
they are either pointed up and down, or, as in Fig. 84 (a), pear-
shaped ; and in the hind-legs they are often like slits in the skin.
I have not seen a second case of a Horse without them on the
hind-legs, but perhaps a more extensive search might discover
some others.

Now, are there any other animals with similar callosities on
their legs? Yes; Professor Flower has mentioned the Memznna
and Tragulus two Deer-like or Swine-like ruminants. In the
Natural History Museum the Huanaco (Lama huanacus) has
similar callosities on both the inner and outer aspects of the hind-
leg below the hock. The Llama (Zama glama) has them also on
both sides of the hind-legs. The Alpaca (Lama pacos) in some
cases seems to have them only on the inner aspect of the hind-legs.”

Fig. 84 (4) gives an outline of the hind-leg of the Alpaca,
showing the callosity ; and Fig. 86 gives a full picture of a living
Llama, with the callosities, as slits,on both aspects of the hind-legs.

It is interesting to note that in the Vicugna (Fig. 84 (¢)), another
Cameloid animal of South America, instead of a callosity, there is,
in this case at all events, in the same region, a distinct tuft of
elongated dark hair on a light ground.

Then again in the Natural History Museum there are various
other ruminants which have, as I think, very significant tufts of
hair on the inner aspects of their hind-legs which are of a different
colour from the general ground colour.

The Elk, the Virginian Deer, and the Peruvian Roebuck—all
American ruminants—have these suspicious tufts of hair on their

1 The callosity on the metatarsus of Tragulus may mean something else (see end
of Part vI.).

2 At Tring, the Vicugna has callosities, like slits, on both aspects of hind-legs, below

the hock; and in the Zoological Gardens both the Huanaco and the Llama have
callosities in the corresponding places.
236 STUDIES IN THE EVOLUTION OF ANIMALS

hocks. In all cases they are of a different colour from the sur-
rounding hair. Fig. 85 gives an outline of their legs. But the
most interesting of all is the male Reindeer of the Natural History

 

 

 

 

Fic, 86.—The Llama, from a photograph, F. G. O. 8., 20040.

Museum. On the inner aspect of its hock it has a large whitish
patch of hair on a dark ground.

There can be little doubt, I think, that these singular tufts of
elongated or modified hair are, as Sir W. Flower suggests, vestiges
CALLOSITIES OF EQUINE ANIMALS AND OTHERS 237

of once glandular surfaces of the skin, which have ceased to be of
any use to the animals that possessed them, and have now ceased
to have selection value. In
some, as in the equine family,
they have dwindled into mere
callosities with thickened
epidermis, while in others
they have become covered
with hair of a different tint
and length from the surround-
ing hair. In ‘the Camels of
South America, with possibly
certain exceptions, they ap-
pear to be in the same condi-
tion as those of the Zebra
and Wild Ass, only much
reduced in size.

It would seem safe to look
upon all these callous surfaces
as vestiges of skin glands, similar to those in front of the eye of
certain Deer, like that shown in Fig. 87.

Sheep have glands between the hoofs of all: four legs; and
goats have them only between the hoofs of their fore-legs, and
sometimes not even there.!

 

Fic. 87.—Gland in front of the eye of Peruvian
Roebuck (Coriacus (Furcifer) antisiensis),

Now we come to another and more obscure point of our
research. What could have been the use of skin glands on the
legs of the common ancestors of all these different mammals—
Horses, Asses, Zebras, Deer, and Camels ?

Well, in the ancestral history of these animals, skin glands on
the legs, which secrete an odoriferous substance, may have been of

1 Royal Natural History, vol. ii. p. 234.
238 STUDIES IN THE EVOLUTION OF ANIMALS

the utmost service for purposes of recognition and discovery, by
leaving traces on the high grass through which they may have
passed, or in which they may have hidden themselves. Mr. F.C.
Selous mentions that on being attacked by natives one night, he
and his men escaped into the jungle grass, which was seven feet
high* In the midst of tall grass, neither keen sight nor keen
hearing would be of much avail, but by leaving a scent on the
grass which rubbed against the leg glands, as the animal passed
through, its companions might succeed in rejoining it. When
hunted by a carnivorous animal, it would have been an advantage
fora herd to scatter, and hide themselves among grass. If they
did so, it would have been an advantage to be able to find each
other again by leaving scent-traces on the grass. Sir W. Flower
says— Some Deer and Antelopes have a suborbital gland secreting
a peculiar oily odorous substance. When the animal is feeding
drops fall on the herbage and indicate to others the whereabouts
of animals of the same species. It is not improbable that the leg
glands had some similar use.

Just imagine how useful such a trace would have been to the
dam in finding its young one, and to the young one in finding
its dam, when they may have wandered away from each other
in the midst of high grass.

Think how useful they would have been in the rutting season
among high grass to the male in finding the female and wice versd.
As I said, such glands were very probably of the same nature
as those in front of the eye of certain Deer.

The reader might perhaps ask—How is it that @// the rumi-
nants have not traces of leg glands? Well, the same question
might be put regarding the suborbital gland, for not all Antelopes
and Deer have it. We don’t know sufficiently the early history

+ In South America miles and miles of plains are covered with the tall Pampas grass.
CALLOSITIES OF EQUINE ANIMALS AND OTHERS 239

of each species from the time it branched off from the common
stock. For all we know, ruminants may have had leg glands,
but some compensating condition may have rendered that feature
of little importance in some of them, and a cessation of selection
in that direction occurred, by which the leg glands were eventually
totally suppressed, while in others traces of them have been left
in the form of patches of hair of different colour and length from
the surrounding hair.

As the Horse has them on all four legs we may assume that
Zebrast and Asses had them also on their hind-legs, although
now they have no traces of them there. It is not only callosities,
but other features may become often lost by suppression. It is
one of the factors in the origin of species.

I have never found anything recorded by hunters of Zebras
on these leg glands. In these animals the callosities are very
large, and something, one would think, might be discovered about
their real nature and structure if proper investigation were made
when the Zebra was fresh after being shot.

It would be very interesting also to ascertain whether in the
Horses which have become again semi-wild in South America
and Australia, these skin glands have ever re-acquired any of
their ancient activity. Not impossibly the ancestral possessors
of these leg glands may have been driven by their enemies from
regions of long grass to more open regions, and rocky places
with shorter grass ; or the long grass of certain regions may have
been devoured by the immense multitudes of these animals which
are recorded by hunters; and so the leg glands may have become
less useful, and by degrees lost their selection value. Anyhow,
it seems more than probable that those singular tufts of hair
were in some ancestral form active skin-glands of some use to

1 Grevy’s Zebra seems to have lost them on both hind- and fore-legs.
240 STUDIES IN THE EVOLUTION OF ANIMALS

the animals that possessed them. And the callosities of the
equine family are probably vestiges of similar glands. The
equine and the ruminant families of mammals would appear
to have branched off from the same stock. In another place I
have given reasons for considering these two sets of animals as
closely allied.

In my opinion there cannot be much doubt that Sir W.
Flower’s suspicion, as to the nature of the callosities of the Horse,
is the right one. They ‘belong undoubtedly,’ he says, ‘to the
category of glandular surfaces.’ They appear to me to be vestiges
of skin-glands which once served a useful purpose in past ages,
and were not unlike the suborbital glands of some kinds of Deer.

Innumerable changes may have naturally occurred on the face
of the countries their ancestors inhabited ; and the advent of man,
of whose antiquity there can be little doubt, has made still further
changes which may have rendered those glands useless, if not
hurtful should they become injured.

Mr. Louis Robinson! has stated that whoever discovers the
meaning of the Horse callosities ‘will become famous among
naturalists all the world over’ Their meaning has already been
suggested by one who is ‘famous all the world over’—viz.
Professor Sir William Flower.

1 North American Review, April 1894, p. 483.
a

THE ONE BIG DIGIT OF THE HORSE
‘Numerous “Lemurs” with marked ungulate characters are being discovered in the
older Tertiaries of the United States and elsewhere... . I am not aware that there is any
means of deciding whether a given fossil skeleton, with skull, teeth, and limbs almost
complete, ought to be ranged with the Lemurs, the insectivora, the carnivora, or the
ungulates.’

Professor HUXLEY— Proceedings of the Zoological Soctety, 1880, p. 65.
PART XI

THE ONE BIG DIGIT OF THE HORSE

PROFESSORS of Biology and Palzontology have been teaching
that the Horse has only ome enlarged digit in its four limbs, with
vestiges of two other digits hidden under the skin (the splint

a ee
a. b = tae
1
i |v
Vv
. ov) be
Vv Y a a iy
i Wow et iv

u iv
uw Ip i m J

Fic, 88.—(a) Foot of an extinct form of Horse-like animal, Pachynolophus (Eocene) ; (3)
of Anchitherium (Early Miocene); (c) of Anchitherium (Late Miocene); (d) of Hipparion
(Pliocene) ; (e) of Zgzus (Pleistocene), and also of the existing Horse ;—from AZammals, by
Flower and Lydekker, p. 377.

bones); and that this big digit owes its origin to one of the digits
(the iii.) in the hand and foot of an extinct animal, repeated with
modification in several other descendants, also extinct, until we reach
that of the Horse—fossil and existing—as shown in Fig. 88.

This enlarged digit is traceable in some other existing animals
244 STUDIES IN THE EVOLUTION OF ANIMALS

of the same line of descent, or branches thereof, such as the
Rhinoceros, the Tapir, etc.

In the Horse it is stated that all other digits have disappeared,
leaving only what are called the ‘splint bones’—insignificant
remnants, or vestiges, which show that originally two other digits
were there. The big one only has remained, becoming bigger and
bigger by absorbing to itself the function of all the normal five
digits. Indeed, in the modern Shire stallion, the hoof is not unlike
a round dish-cover.

In the Natural History Museum? there is arranged a very
pretty gradation of specimens, commencing from an ancient
extinct type, which has one big digit (the iii.) in the middle of four
smaller ones, and going up to the one solitary digit of the Horse.

It has become a sort of dogma that the hand and foot of the
Horse are different from the hand and foot of the Ox ; the former
being, it is supposed, ove enlarged digit, and the latter ¢wo dis-
tinct digits; and further, that these two animals belong to two
different groups, the Horse belonging to the uneven-toed group
(Perissodactyls), and the Pig, Ox, etc., to the even-toed group
(Artiodactyls).

As so many professors of note have embraced and propounded
this theory, it might seem a bold sort of presumption on my part
to re-open the question, which has become the basis of an estab-
lished conviction among biologists. But facts, they say, are
stubborn things. I shall place before the reader certain facts,
which are my reason for re-opening this interesting question.

In discussing a subject like this it is well to begin at the
beginning. In the Natural History Museum, gallery of fossils,
case 9 (c. d.), there is a cast of an extinct animal—Phenacodus
primevus (Eocene)—not larger than a biggish Dog, with five digits

1 Fossil Gallery, case 9.
THE ONE BIG DIGIT OF THE HORSE 245

in its hand and foot. Each digit ends in what is supposed to have
been a small hoof, so that this little extinct animal would appear
to have been a five-hoofed mammal. It has the middle digit (the
iii.) of each limb enlarged. So there is evidence in support of
the possibility that this enlarged middle digit of Phenacodus, or of
some animal like it, may have persisted in the innumerable
modifications which must have occurred, and have become the
ancestor of the solitary digit of the modern Horse. Indeed, the
evidence of the gradations from the former to the latter by gradual
loss of all the digits, excepting the middle one (the iii.), seems
complete and satisfactory.

In Fig. 88, it will be seen that Pachynolophus had already lost
one of its Phcenacodal digits, viz. the big toe. Some weakness
of innervation and diminution of circulation in a part will lead to
disuse, and consequent dwindling, and eventual suppression.

All the specimens in the Natural History Museum are being so
beautifully arranged that all who can read may learn. One thing
is wanted there—viz., a lecturing theatre, and some endowment left
by some rich person for lectures, to teach the people the great
philosophy of evolution.

There are known several other allied extinct animals with a
hand and foot, probably derivable from some five-digited animal
like Phenacodus, such as Hyracotherium venticolum, Paleotherium,
etc.

Mr. Hutchinson? makes the following suggestion: ‘One
cannot help sometimes wondering whether to some extent the
wil of an animal may not be an important factor in evolution,
although it is the fashion to ignore it, and to attribute organic
changes to natural selection, or the “ survival of the fittest.” Mind
has a powerful influence over matter,? and can we not conceive

1 Creatures of Other Days, p. 214, 2 Yet the two are zxseparable.
246 STUDIES IN THE EVOLUTION OF ANIMALS

that the earliest ancestors of the Horse, such as Phenacodus, find-
ing (perhaps for the first time in the world’s history) boundless
grassy plains before them, were impelled by a strong desire to run?
The exercise itself must have been enjoyable and invigorating ;
besides, the more ground they could cover ina day the greater
choice of pasture they would find, while at the same time increased
swiftness of foot meant greater safety from flesh-eating enemies.’

The ‘ will, being dependent on some special centre in the brain,
cannot possibly be excluded from being a factor, or part of a
factor, in natural selection. Probably there is no part of the
organism which does not contribute its quota towards the co-
operative factorshi~ in natural selection. As to the running being
‘enjoyable and invigorating,’ one has only to observe a young Foal
in a paddock, or the young Eland in its paddock at the Zoological
Gardens, to be convinced of the enjoyability of galloping round
and round the paddock, as if imaginary devils were running after
it. These young animals seem to do it with no other object than
that of ‘enjoying a gallop’—a sort of exuberant joze de vivre, no
doubt impulsed by plenty of nourishing mother’s milk.

The reader who may not have paid much attention to the
interesting doctrine of evolution should not suppose that, because
the dray Horse is of elephantine dimensions, it could not have
descended from an animal as small as a big Dog; for there have
been pigmy Elephants and giant Elephants, pigmy Deer and giant
Deer, pigmy Lizards and giant Lizards, pigmy Men and giant Men,
and so forth. Large size would appear to be rather a matter of
luxuriant feeding which contains all the ingredients of bone,
muscle, nerve, etc., and of ease in obtaining it, while small size is
the reverse, the structure of the two—large and small—remaining,
bone for bone, muscle for muscle, identical, and therefore
evidence of derivation from a common stock. Of course a giant
THE ONE BIG DIGIT OF THE HORSE 247

Elephant could not pair with a diminutive one, and thus the two
breeds would remain distinct.

Mr. J. I. Lupton! is of opinion that ‘The land upon which
every species of animal is bred exerts a powerful
influence upon it for good or evil. We find
that a sterile soil will stunt the growth of animal
life, whereas a rich one will promote vigour,
size, and stoutness.’

Although abundance of food, or the reverse,
may have a great deal to do with giant and
dwarf forms, still the abnormal size may have
been initiated as a montrosity suddenly?

Fic. 89.—Abnormal

Then the Pachynolophus form of foot would jana ofa Pig, (a) being
seem derivable from a Phcenacodus form of the thumb, and (é) the
foot: ‘The latter haa five digits, with the third “21 o. moa ein
enlarged, while the former has only four, with oe nae
the corresponding, or homologous one, also translation of Chau-
enlarged, while its big toe is suppressed. eg

It should be noted that, as an anomaly, the _p. 122.
hand of the Pig sometimes comes out with five
digits as shown in Fig. 89. The curious part of this anomalous
Pig’s hand is that one of the carpal bones,—the trapezium (4)—is
completely fused with the metacarpal bone of the thumb.

From this anomalous hand it would appear that the sub-division

 

of the ungulates or hoofed mammals into uneven-toed and even-
toed is rather arbitrary, for here is an even-toed Pig giving birth to
an uneven-toed child. Of course both sub-divisions originated from
the same stock; but two Greek names to indicate a condition

1 © Pedigrees of British and American Horses’ (Mineteenth Century, June 1894,

p. 926).
2 See ‘ Nanisme et Geantisme,’ Guinard, Précis de Tératologie.
248 STUDIES IN THE EVOLUTION OF ANIMALS

which is not permanent might be dispensed with as advantageously
as the two suppressed digits of the Horse!

The reader might say that from the series of limbs shown in
Fig. 88 it is clear that the one digit of the Horse is derived from the
big middle digit of some animal like Phenocodus. Suppression of
parts is seen to be such a common phenomenon in the process of
evolution throughout the animal kingdom, nay, throughout the
whole of what we call living nature, that it is the most rational
conclusion to come to. Allied animals had five digits, therefore
those that have less have lost some by suppression..

With reference to the evolution of the Horse, as evidenced by
the feet of the fossil forms of the Horse tribe, Dr. Alfred Russel
Wallace! writes: ‘Well may Professor Huxley say that this is
demonstrative evidence of evolution; the doctrine resting upon
exactly as secure a foundation as the Copernican theory of the
motions of the heavenly bodies at the time of its promulgation.
Both have the same basis—the coincidence of the observed facts
with the theoretical requirements.’

There can be no doubt about the evolution of the Horse from
some such ancient form as that of the Eohzppus. The question
in this discussion is restricted to the origin of the big digit in the
whole series, that is, whether it was originally ove digit, or a fusion
of Zwo,

I might perhaps say that I do not dispute that the origin of the
existing Horse’s digit is as stated, but I would now ask—Are we
so ‘cocksure’ that Phenacodus is to be credited with only jive
digits, instead of szx?

I confess it seems preposterous to ask such a question as this,
when there is more than abundant evidence to show that our own
hand and foot, like those of so many mammals, are formed on the

1 Darwinism, p. 389.
THE ONE BIG DIGIT OF THE HORSE 249

same plan. I think the dogma that our hand is made up of five
digits only, like that of Phenacodus, is not so unquestionable as
might at first appear.

Modifications have been so vast, from the first appearance of a
hand and foot, in vertebrates, up to the form with five digits, that
it is next to impossible always to discover, in the whole series,
which bones are homologous.

In the changes that the carpal and tarsal bones have been
subjected to, it is not easy to identify their position regarding the
metacarpal and metatarsal bones. For instance, in the extinct
Coryphon and the Titanothere, there is already a displacement of
wrist and ankle bones. If in these primitive animals the change
of position is already considerable, what shall we say of their posi-
tion in the Horse and Ox? and in the tarsal bones of Man the
change of position is vast.

In the higher mammals, where these limbs have not been much
modified in structure, of course the homologies of bones may
be easily ascertained. But even here it is not always easy to
do so.

Flower and Lydekker? give the right hand of a water Tortoise
(Chelydva Serpentina), Fig. 94. It is an animal far removed from
mammals, but nevertheless it has five digits in its hand, and is
evidently related to the human hand. It has a separate carpal
bone to each digit, all in one row. This order becomes much
modified in the carpus of other animals, so much so that Chauveau ?
says: ‘The human hand having five digits and five metacarpal
bones, it is rational to admit the virtual existence of five pieces to
each of the carpal rows. Materially, there are only four bones in
each of the rows; but the comparative study of the relations of

1 Royal Natural History, p. 152. 2 Mammals, p. 48.
3 Anatom. Comp. des Animaux domestiques, tr. by Fleming, p. 123.
250 STUDIES IN THE EVOLUTION OF ANIMALS

each of these bones in the human carpus, and in that of animals
which are in possession of the archetypal hand, leads to the belief
that the scaphoid is the result of fusion of the fourth and fifth bones
of the upper row, and the awmuciform the fusion of the first and
second bones of the inferior row. This may be so, but let us
see what Sir W. H. Flower! has to say on the homologies of
carpal bones.

‘The determination of the homologies of the carpal bones of
the Cetacea with those of other mammalia is beset with diff-
culties, and has consequently led to some differences of opinion
among those anatomists who have attempted it. Moreover,
every species appears liable to certain individual variations, and
sometimes the different sides of the same animal are not precisely
alike, either in arrangement or even the number of the carpal
ossifications. . . . In many cases, as in the round-headed Dolphin,
the bones of the distal row of the carpus are reduced to two, which
appear to correspond best with the trapezoid and unciform, the
magnum being either absent or amalgamated with the trapezoid.
The trapezium appears never to be present (in the Cetacea) as a
distinct bone, although the first metacarpal so often assumes the
characters and position of a carpal bone that it may easily be
mistaken for it,

Further, some species of Woolly Spider Monkeys (Zrzodes
arachnoides) have a rudiment of a thumb on one hand, and not a
trace of one on the other.”

Note that ‘ sometimes the different sides of the same animal are
not precisely alike, either in arrangement, or even the number of the
carpal ossifications.’

If the two sides of the same individual are liable to variation in

1 Osteology of Mammals, p. 301, 3rd Edit.
2 Royal Natural History, vol, i. p. 158.
THE ONE BIG DIGIT OF THE HORSE 251

arrangement and number, what shall we say of the liability to varia-
tion in individuals and races, separated from each other perhaps by
millions of generations, and subjected to different nervous influ-
ences, and to the action of different surroundings ?

It is evident to me that in many instances homologies are rather
assumed than proved; and it will be seen how difficult it may be
to determine in all cases what particular bone in the hand or foot
of one animal is homologous with another bone in the hand and
foot of another animal.

Therefore we cannot always be ‘cocksure’ that in these cases
our inferences are beyond question.

Professor Huxley says, ‘In matters of the intellect do not
pretend that conclusions are certain which are not demonstrated or
demonstrable,’

We have now to face four cases of abnormalities, which may
interfere with the notion that there is, as Chauveau and others
think, such a thing as an archetypal hand or foot with five digits.
These are as follows:

A. In Chauveau’s work! are given two instances of abnormal
hands in Horses, a sketch of which is shown in Fig. 90. There can
hardly be much doubt that these so-called monstrosities are only
reversions (at least they mzght be so interpreted) to some very
remote type from which the Horse descended, the Ox and its
congeners having continued that remote line of type up to the
present day.

We might suppose that while the hand and foot of the Horse
have become consolidated throughout into one digit, those of the Ox
have become consolidated only as far as the metacarpal and meta-
tarsal bones, leaving the phalangeal portions of the two digits free.

I do not see how we can escape from some such conclusion as

1 Anatom. Compar, des animaux domestigues, p. 130.
252 STUDIES IN THE EVOLUTION OF ANIMALS

this, seeing that Fig. 90 (6) could stand for the hand of an Ox or
Ram. As shown in (c), it does not materially differ from it.

A third case of cloven hoof in the Horse was pointed out to me
by Professor M‘Fadyean of the Royal Veterinary College, and

 

Fic. 90,—(a) Abnormal hand of a Horse; (4) abnormal hand of a Colt, split into two
digits, like that of a Ram, from Chauveau's Azat. Comp., p. 130; (c) normal hand of an
Ox, from Professor M‘Fadyean’s Compar. Anat. of Dom. Animals, Fig. 87.

illustrated in the Journal of Comparative Pathology and Therapeutics,
vol. iii. pt. 3, September 1890, p. 263.

B. The fourth abnormality we have to face is this: All osteolo-
gists know that long bones have a nutrient foramen for the passage
of an artery into the interior of the bone. Well, Professor
M‘Fadyean, in his work on The Horse, on p. 153, Fig. 113, gives
the left metatarsal bone of a Horse with ¢wo nutrient foramina
where generally there is only ome.
THE ONE BIG DIGIT OF THE HORSE 253

Even if there were a/ways only one nutrient foramen in this
bone of the Horse, it would be no evidence that the Horse’s meta-
tarsal bone is not genetically made up of a fusion of two, for all the
Ox family which I have examined in the Natural History Museum
have only one nutrient foramen in their metatarsal bones, although
they are admittedly made up of a fusion of two distinct bones! There-
fore this case of two foramina given by Professor M‘Fadyean is
the more remarkable and important.

This abnormality and those cloven Horse’s hands quoted from
Chauveau’s work, and by Professor M‘Fadyean, render it question-
able whether the Horse’s digit is merely an enlarged one digit
(the iii.) as was supposed.

I think that these teratological facts induce at least a suspicéon,
if not a conviction, that the Horse’s hand and foot may after all be
double organs in origin, like those of the Ox, fused into one, not
only in the metacarpal and metatarsal portions, as in the Ox, but
also in their phalangeal portions, that is, throughout, so as to
produce one solid hoof.

If the Horse’s metatarsal bone given by Professor M‘Fadyean is
not a compound of two bones, then I do not see what business it has
with ¢wo nutrient foramina. I would ask,—Why did two foramina
come there at all, when one is the normal state of things in Horses,
and when one is quite sufficient for the two fused bones of the
ruminants I have mentioned, 7f there were no reminiscence of two
bones in orig¢n?

You might ask,—If, as you suppose, the common bone of the
Horse may. be a fusion of two, why does it never disclose the line of
suture, as in the Ox? Well, we do not know that in the millions of
Horses which have been bred no such disclosure has occurred ; all we
know is that it has not been noticed and recorded except in cases of
Cow-foot. Moreover, there are many skeletons of ruminants in the
254 STUDIES IN THE EVOLUTION OF ANIMALS

Natural History Museum, the cannon bones of which have no
trace of suture. Professor Marsh, who has devoted much attention
to recent polydactyle Horses, gives a figure of the horned Horse of
Texas That this particular polydactyle Horse was also horned may
be of some importance in comparing the limbs of Horses and Oxen.

Professor Marsh mentions that Julius Cesar ‘used to ride a
remarkable Horse, which had feet that were almost human, the
hoofs being cleft like toes.’ He gives several cases of additional
digits in the Horse, besides the usual one big digit. But none of
these seem to be of the nature of the Cow-foot of Chauveau and
M‘Fadyean.

The size of a digit would naturally depend to a large extent on
the fact of the weight of the body being thrown principally on that
particular digit. In the Tapir, Rhinoceros, and Elephant, it was
thrown on the third; in the Horse, if uneven-toed, also on the
third, but if even-toed, like the ruminants, the weight was thrown
equally on the third and fourth. In man it is thrown on the first
of the foot2 In Cheropus Castanotis, a marsupial, we have in the
hand the third digit largest, while in the foot the fourth is largest
and the rest more or less atrophied.

It must not be supposed that a two-digited Ox cannot run as
quickly as a one-digited Horse. When in Kandy (Ceylon), I one
day hired a wagonette with one large Horse to take me to Pera-
denya. The Horse trotted all the way. Behind us was a small
Zebu Ox harnessed to a native cart. It trotted all the way, and
always kept the same distance behind us. Rich natives in India
keep large Hansi Oxen, which are very good trotters. I should
say there are not many Horses that can gallop as fast as an

1 American Journal of Science, third series, vol. 43, 1892, p. 344.

2 Some men wear the heels of their boots on the oufer side, which means that they
walk somewhat like a Gorilla, and throw their weight on the ozészde of their feet, and
therefore on the szalles¢ of their toes.
THE ONE BIG DIGIT OF THE HORSE 255

Antelope; and Dogs with five toes in front and four behind can
gallop as fast as Horses.

Then there are so many cases—whole families sometimes—
quoted by Darwin, Guinard, and others, of which I have given
details in another place, who had szx digits in hands and feet.

If there be such a thing as an archetypal hand and foot with
five digits, where did these numerous persons, and other animals,
get their sixth digit from ?

The theory of Flower and Lydekker, and others, that the one
digit of the Horse is derived from the big middle digit of Hzpparion,
and this from that of Auchitherium, and this from the big digit of
Pachynolophus, and this again from the enlarged middle digit (the
iii.) of a Phaenacodus, would seem to be plain sailing. But one
would like to ask again, Are the hand and foot of Phenacodus
composed of five digits or of six, with the middle one a fusion
of two?

This question would seem so preposterous that it almost takes
one’s breath away to penit! Yet teratological facts leave us no
alternative but to ask it. Facts are so stubborn that they give one
no peace till they are somehow explained.

_When we see that the Leopard of to-day still carries on its skin
the impressions of plate-armour with which its ancestors millions
of years ago may have had their bodies protected, the notion that
the Horse’s foot is an amalgamation of two ancestral digits which
may have occurred millions of years ago does not after all seem
so startling, Just think of the immense family of orchids. Some
incredible time ago their ancestral pistil and stamen became fused
and transformed into the modern orchid-columnz. Yet through the
innumerable variations that this curious flower has undergone, from
the size of a large pin’s head to that of a tea saucer, this character-
istic feature has ferszsted. And it is only now and again, by some
256 STUDIES IN THE EVOLUTION OF ANIMALS

teratological specimen which happens to turn up, that the secret
of its origin is revealed.

The question is whether there is any evidence to show that the
Horse and the Ox may be more closely related than the Horse is to
the Rhinoceros, I think there is. There is, however, no doubt that
all three, the Horse, the Ox, and the Rhinoceros, at some still
remoter period came from the same stock.

It might be said that nothing is easier than to identify the
thumb or big toe, which have only two phalanges, while the other
digits have three. Even in the foot of the Seal (Macrorhinus Leo-
ninus), where both the thumb and little finger are about of equal
length, and both prolonged beyond the other three digits, the

1 See Dr. Maxwell T. Master’s Vegetable Teratology, pp. 380-384.

2 In Creatures of Other Days, pl. 21, Mr. Hutchinson has clothed Phanacodus with
longitudinal stripes somewhat like a Paca, or like the common American Tapir ; and Hyra-
cotherium with stripes like a Zebra. For reasons given in another place, it is more
probable that these two ancient mammals were dappled, somewhat in the manner of a
Leopard. As delineated, they are too much like modern striped animals. But as they
were, as has already been suggested, nearer to their ancestral Glyptodontoid forms, the
markings in those early days could hardly have been so modified as those of the Zebra
and Tiger of these days. They seem to have been given a recent dress over an ancient
skeleton.

Then on pl. 23 Mr. Hutchinson gives a Sabre-toothed Tiger attacking a Afacrauchenia.
This carnivore is shown as striped, like the existing Tiger. Now, the striping of the
Tiger, as I have endeavoured to prove, is a much modified rosetting. It does not at all
follow that, because the skeleton of the sabre-toothed carnivore is like that of a Tiger,
therefore its skin-marking was like the Tiger of our days. It is more likely that it was
rosetted like a Jaguar, not only because it was zearer the basis of its own evolutionary
branch, but also because it comes from the Pampas formations, from which region the
Jaguar also comes. Curiously enough, in the Saturday Review of 15th September 1894,
p. 306, in a review of Mr. Hutchinson’s Creatzres of Other Days, I find this :—‘ Here are
represented two ancient and ancestral mammals, the Phanacodus and the Hyracotherium :
the former is ornamented with longitudinal stripes, and the latter with transverse bands
like a Zebra. Still it is better to have done this than to have taken the greater liberty
of making them spotted.’

The reverse is not improbably the case, considering that such a large number of
American mammals are spotted, including a large proportion of the fawns of the Ameri-
can Deer.

3 Given by Professor Flower in Osteology of Mammals, p. 347.
THE ONE BIG DIGIT OF THE HORSE 257

thumb with only two phalanges can be readily made out. True,
but in this discussion I am taking into consideration not only a
broad evolution reaching to the most ancient forms in which we
can clearly identify what we call a hand and a foot, but also éera-
tological, or monstrous specimens. Now and again these peep out
of oblivion to reveal something of the invisible past, and therefore
cannot be ignored in framing evolutionary theories.

Although the thumb and big toe are readily identifiable in
series of Mammals, from their having only two phalanges, it
would appear that the thumb before it got shortened and partially
atrophied, and separated from the other digits, also had three
phalanges, like the other digits; for in Fleming’s translation of
Chauveau’s work! an abnormal hand of a Pig is given (Fig. 89 of
these pages), in which the five digits are present, and the thumb is
shown with ¢kree phalanges:* moreover, its metacarpal bone is
amalgamated with the trapezium of the carpus.

Then in the Ichthyosaurs there does not seem to be any dis-
tinction between the thumb and the other digits ; and when we
consider the large number of phalanges there is in the hand and
foot of these extinct animals, we begin to see that homology,
beyond a certain stage, cannot always be traced simply from the
number of bones in a limb. The carpal bones in their descent
have undergone so much alteration and displacement that no
accurate conclusion can be drawn from this source in all cases.
Even in Monkeys, the majority of which have five digits, there is
a section with ezgh¢, and another with zzze carpal bones.

Why this so-called archetypal form of limb gave rise to such
a vast series of five-digited animals we cannot tell. We may,
however, assert with some confidence that it was not the five digits

1 Comparative Anatomy of Domestic Animals, p. 122.
2 Supposing this not to be an oversight.

R
258 STUDIES IN THE EVOLUTION OF ANIMALS

which gave the ancestral forms pre-eminence, and enabled them to
stamp this feature on millions of descendants, but some other
anatomical and physiological characters, developing concurrently
with the five-digited hand and foot, which enabled that type to
endure and fight its way to our times. Four, three, two, and
perhaps even one digit were enough to secure survival. It would
seem that it was. not so much the limbs as the drain and viscera
which gained the day, in spite of the diminishing number of
digits.

It seems impossible to account for atrophy of one or more
bones, which may sometimes occur all of a sudden, and give rise
to what is called an anomaly. If the abnormality or monstrosity
should happen to be useful, or can suit itself to surrounding con-
ditions, it may endure, and be reproduced, and possibly lay the
foundation of what might subsequently be called a ormality. As
an abnormality, the animal may have originally been better off in
the struggle for existence. Certainly the struggle must be more
keen among those who have exactly the same structure.

I remember seeing in Jeypore, Rajpootana, an adult who had
no arms at all. In what corresponded to the glenoid cavity of the
scapula there was a small finger, or at least what looked like one.

Here then was a case not merely of atrophy of four digits
with their metacarpal and carpal bones, but suppression of the
whole radius, ulna, humerus, etc. Of course, such a monstrosity as
this was anything but useful, and not likely to endure,

On the occasion that Professor M‘Fadyean showed me the case
of cloven foot in a Horse, in the Journal of Comparative Pathology
and Therapeutics, already mentioned, he remarked that the phe-
nomenon was not very uncommon. The abnormality he showed
me was in a Horse four years old, and in only one foot.

The Professor did not seem to look upon this anomaly as a
THE ONE BIG DIGIT OF THE HORSE 259

case of reversion, because the metacarpal and metatarsal bones of
the Horse, unlike those of the Ox, were séugle bones, I remarked
that the case, in his book on The Horse, of a metatarsal bone with
Zwo nutrient foramina, threw some doubt on the theory that these
bones in the Horse were ordgénally only one bone, He replied—
‘Then, if these bones are made up of a fusion of two, you would
have to credit the Horse with having had six digits originally” I
said that would exactly correspond to the séx digits in the hand
and foot of numerous persons mentioned by Darwin and others.

I do not think that we are justified in beginning to count from
either a Phanacodus, or any other extinct animal previous to it,
with five digits to its hand and foot, and then call these ‘ archetypal ’
hand and foot, for these extinct animals were not the commence-
ment of the vertebrate type, and behind them there may have been
other extinct animals which may have had szr digits. True
enough, we have not yet found fossil animals with normally six
digits, but we have found some with move than six.

There can be no doubt that certain digits can become hyper-
trophied, and then, through natural selection, the enlargement
might be continued, and even increased; but what I have some
doubt about is whether the Horse's digit was originally an enlarged
one, or a fusion of ¢wo digits.

The abnormal examples given by Chauveau and M‘Fadyean,
which are like the cloven foot of the Ox, and the example of two
nutrient foramina in the metatarsal bone of a Horse, certainly tend
to throw doubt on the accepted origin of the Horse’s digit as a
hypertrophied ome digit. These abnormalities may be as im-
portant, in a sense, as the discovery of the archeopteryx.

When we begin to search lower down in the scale of vertebrates
than Phenacodus to try and. find out where it got its five digits
from, what do we find?
260 STUDIES IN THE EVOLUTION OF ANIMALS

In the Natural History Museum there is a fine collection of
Ichthyosaurs of the Mesozoic period. Nobody can doubt that their
four limbs, however rudimentary, as judged by our own hands and
feet, are the homologues of the four limbs of the higher vertebrates.
Well, in these Ichthyosaurs the digits of the hands, or what corre-
spond to digits, vary from four to eight. In several instances one
of the digits appears as if it were dwindling off. The carpal bones
are hardly distinguishable from the metacarpal and phalangeal
bones, which are very numerous, showing that in the higher verte-
brates the phalanges are reduced in number, either by suppression
or by coalescence. What is very notable is the fact that in some
the hind-legs are comparatively small, and with a reduced number
of digits.

This may perhaps be the reason why some of the higher
vertebrates, such as the Tapir, Rhinoceros, and usually the Dog,
etc, have a reduced number of digits in thezr hind limbs. There
certainly does not seem to be any good reason for this reduction
which can be drawn from usefulness and natural selection.

Here then in this Ichthyosaur plane of life we have a basis out
of which several archetypal hands and feet could have arisen. It
only needed that each monstrosity should have been repeated
through heredity, and made permanent by survival, as a race fit to
cope with its surrounding difficulties.

In the Plesiosaurs, which apparently are closely allied to the
Ichthyosaurs, although they have a much longer neck,! we find
that the hand had already settled down from the many-digited to
the five-digited type, as shown in Fig. 93. And there would seem
little room for doubt that the Plesiosaur hand, or one like it, was

1 Some of the Tortoises have a much longer neck than any of the Crocodiles ; and in
the snakes it is not easy to say where the neck commences and where it ends; yet all
three sections are closely allied.
THE ONE BIG DIGIT OF THE HORSE 261

the ancestral form of the Dolphin’s hand (Glodccephalus-smelas) as
delineated in Flower’s Osteology of Mammals, p. 302, in which two
of the digits remain almost Plesiosaurian, and the remaining three
are vastly modified by atrophy.

In this Round-headed Dolphin, the carpus has become
differentiated from the metacarpus and phalanges with a probably
greater mobility of the hand. Here is a comparison of the hands
of two Dolphins, showing the number of phalanges, including the
metacarpals, as given in Flower’s Osteology of Mammals, p. 303 :—

Globicephalus melas. Delphinus.
thumb, ; four two
index, ; fourteen : ten
middle finger, nine seven
ring finger,. three three
little finger, one é one

So that in closely allied animals the number of phalanges can
be vastly different.

It is not known whether the Ichthyosaurs and the Plesiosaurs
were oviparous or viviparous. Hawkins, in the book of the Great
Sea-Dragons, p. 18, says—‘ We had hitherto supposed these Sea-
Dragons oviparous, and now we are tempted to think them
mammal.’

Judging from the skeleton of the hand one would be inclined
to infer that, like the Dolphin, the Plesiosaur, in spite of its long
neck, was a mammal.?

When we begin to compare the hands and feet of vertebrates,
it is astonishing what modifications they have undergone. - For

1 In reality the distinction between oviparous and viviparous animals is only nominal,
for in the Australian Platypus we have an oviparous mammal.
262 STUDIES IN THE EVOLUTION OF ANIMALS

instance—the Alligator (Cazman latirostris) has only four digits in
the hind-limb, thus furnished :—

Ist digit, two phalanges,
2nd digit, . three phalanges,
3rd and 4th digits, four phalanges each.

Then in the Brazilian Tortoise (Zestudo tabulata) the hind-limb
is as follows :—

Ist digit, . : two phalanges,
2nd, 3rd and 4th digits, two phalanges each,
5th digit, may be one, or may be two ;

and all the bones of the first row of the tarsus are lumped into ove
bone, so that the modifications in the foot of this Tortoise have
been very great.

If we turn to the birds, we find the modifications in their hands
and feet still more astonishing.

Among mammals, again, we find a curious modification in the
hand of the Little Ant-eater (Cycloturus didactylus). The third
digit has only two phalanges, a stout and broad metacarpal bone,
and the distal row of the carpus is often lumped into ove bone.

These are a few examples of animals in which the bones of the
hand have become so modified as to make it very doubtful
whether all their homologies can any longer be traced. The study
of the young animals where the ossification may be still incomplete
will no doubt help in discovering their homologies. But it requires
great faith in the acumen of a professor to believe implicitly all he
may write or say regarding homologies; for in this little Ant-
eater’s hand! the bone marked (v.), as the rudiment of a fifth digit,
may be one of the carpal bones, and that marked (tm), as the
trapezium, may be the metacarpal bone of the first digit!

1 Fig. 108—-Flower’s Osteology of Mammals.
THE ONE BIG’ DIGIT OF THE HORSE 263

Atrophy and subsequent suppression, enlargement and fusion,
are some of the factors of modification in the skeletons of verte-
brates ; and we have seen that in the hand of the Plesiosaur and
the Round-headed Dolphin there is no distinction between the
metacarpal bones and the phalanges.

The more one makes researches to discover at what period the
so-called archetypal hand with five digits took form, the more one
loses faith in there ever having been such a thing. From the hand
with many digits the hand with five digits evolved, and this
continued to lose other digits till only one has remained, as is
supposed, in the Horse. All that can be said in favour of an
archetypal hand is, that a large number of vertebrates have five
digits in their fore-limb, and that probably they evolved from a
many-digited type after it had lost several of its original digits, and
was temporarily reduced to five. We have seen that some of the
specimens of Ichthyosaurs in the Natural History Museum have
as many as eight digits in their hand.

I suppose there is no osteologist who believes that this so-
called archetypal hand was created a znztzo with five digits!

It is not only in extinct animals, but also in recent ones, that
we find a large number of phalanges—as shown by Professor Flower
in the two fingers of the Round-headed Dolphin. Curiously
enough, although this mammal has retained some of the general
characters of the Plesiosaurian hand, it has got rid of its legs
entirely. We have seen that in the Ichthyosaurs the hind-limbs
were already dwindling. We cannot know which set of extinct
animals eventually branched off into the mammal type, and we
have no means of knowing whether that immense series of extinct
animals, provisionally grouped under the name of Dinosaurs, were
oviparous or viviparous. Indeed, as I said, this distinction is not of
much importance, seeing that viviparous means hatched inside the
264 STUDIES IN THE EVOLUTION OF ANIMALS

womb and then brought forth, and oviparous means first brought
forth and then hatched outside. We know that there are both
oviparous and viviparous fishes. We have some indication that this
so-called archetypal hand or foot may have commenced as low
down as in the fishes; for Fig. 91 (2) would seem to indicate
distinctly, in this Fish’s foot, the beginning of a limb with five
digits, which is not very different, externally at least, from the foot
of the mammal, (4). Then the pectoral fins of shore-fishes and
land-fishes, with six or more digits, or what would correspond to
digits, as shown in (c), (@), (e), are very suggestive. In some verte-
brates we call these limbs pectoral and ventral fins, while in others
we call them hands and feet; many zoologists, however, consider
them homologous.

Few, I imagine, would deny that the pelvic fin of Raza clavata,
shown in Fig. 91 (7), does not foreshadow the hand and foot
of the higher animals. Between the two outer big digits there are
many embryonic digits, some of which are not at all dissimilar to the
dwarfed digits of the Kangaroo foot (Macropus Bennetiz), shown
in Fig. 122 of Sir William Flower’s Osteology of Mammals.
Whether the minute digits of this Kangaroo have been degraded
from a fully developed five-digited limb, or whether they originated
from some fish-like limb, and have never been promoted into
useful digits, I leave for others to decide.

The duck-billed Platypus is a marsupial of very low type, and
a good swimmer. Is there any good reason for supposing that it
could zot have been evolved from some fish-like vertebrate, with
fins like those of the land-fish? We know that certain fish can
breathe both by gills and by lungs; and we know that the Frog, in
its early life, is a fish-like animal, breathing by gills, and in its later
life it is amphibious, and breathes by lungs.

It is not easy to get rid of the notion that in this Lophius and
THE ONE BIG DIGIT OF THE HORSE 265

 

FIG. 91.—(a) Left pelvic fin of Lophius piscatorius (Natural History Museum); (4) hind-
foot of an Otter (Exhydris Lutris), Proc. Zool. Soc. 1865, p. 100; (c) foot of a shore-fish
(Lophius Naresii), Challenger Exped. Zoology, vol. i. pl. 25 ; (@) hand of land-fish (Periophthal-
mus), Marvels of Animal Life, by Ch. Fr. Holder, pl. v; (e) limb of a shore-fish (Zanclo-

rhynchus spinifer), Challenger Exped. Zoology, vol. i. pl. 8; (f) fin of Raia clavata, right pelvic
(Natural History Museum). 5
266 STUDIES IN THE EVOLUTION OF ANIMALS

Raia, we have Nature’s first tentative rough models of our own
hands and feet!

The present classification of vertebrates would be hardly
possible if a the extinct mammals, and all intermediate forms,
which have been either naturally selected out of existence or
destroyed by earthly catastrophes, were present before the mind
of the zoologist ; for the whole series would be more or less a con-
tinuous chain without the distinct walls of division or separation,
which sometimes form gaps in the present classification.

Professor Agassiz! truly said: ‘I have already stated that classi-
fication seems to me to rest upon too narrow a foundation when
it is chiefly based upon structure. Animals are linked together as
closely by their mode of development, by their relative standing in
their respective classes, by the order in which they have made their
appearance upon earth, by their geographical distribution,? and
generally by their connection with the world in which they live, as
by their anatomy. All these relations should therefore be fully
expressed in a natural classification; and though structure
furnishes the most direct indication of some of these relations,
always appreciable under every circumstance, other considerations
should not be neglected which may complete our insight into the
general plan of creation.’

The upshot of all this discussion about the Horse’s big digit is
to create a suspicion that it is possibly zof an enlargement solely
of an ancestral ¢hzrd digit, but a fusion of the ¢wo digits of some
Ox-like ancestor.

We know that the Ox—an animal seemingly much allied to the

1 Contributions to the Natural History of the United States, quoted by Dr. C. F.
Holder in Life and Work of L. Agassiz, p. 183.
? Geographical distribution often uz/inks animals. It is only by supposing some

means of translation that two distantly located animals of the same or similar species
can be considered as having had a common origin.
THE ONE BIG DIGIT OF THE HORSE 267

Horse, as I shall show—and its congeners have the metacarpal
and metatarsal bones fused into one ‘cannon’ bone, while the
phalangeal portions are separate. We know also that the Horse
sometimes reproduces the separation of the phalangeal portions in
what is commonly called the cloven-foot or Cow-foot. It is true
that in ruminants the cannon-bone has usually a groove which
indicates the fusion of two separate bones ancestrally, as shown in
Fig. 90 (¢); but the abnormal Cow-foot of (4) shows a similar
groove in the lower portion of the homologous bone.

In support of the suspicion that the Horse’s one big digit may
possibly be a fusion of the two digits of an Ox-like ancestor, I
shall now mention certain other features which are common to
certain ruminants and also to Horses.

(a) In another place I have mentioned that the Horse has
frequently a white blaze, and white hands and feet. These features
are almost exactly matched in the African Antelope (Damalzs
Pycarga), the Bonté Bok.

(6) The maculations of the Giraffe would appear to be fuszons
of maculations similar to those of the Horse; but the maculations
of the Zebu of Fig. 58 scarcely admit of a doubt that the
markings of the Zebu and those of the Horse of Fig. 36 are
identical.

(c) The brindled Guz is striped much like a Zebra, and their
manes are very similar. Moreover, I have often seen Horses faintly
brindled on the neck almost exactly like the brindled Gnu. Then
the Gnu’s tail is more like that of a Horse than that of other
ruminants. On one occasion I was watching the white-tailed
Gnus in the Zoological Gardens. One of them pretended to shy
at nothing, just as a young Horse often does.

So that in the Gnu we seem to have an intermediate form between
the Horse and other ruminants. It has a short mane, like that of
268 STUDIES IN THE EVOLUTION OF ANIMALS

the Zebra ; it is striped not very unlike a Zebra or Quagga ; it has
long hair under its chin, which many cart-horses have; its tail is
like that of a Horse; the white-tailed Gnu shies exactly like a
Horse; but this Gnu has a tuft of hair over its nose which is
unique, and may be somehow related to the horn on the nose
of the Rhinoceros, and which is stated to consist of an agglutina-
tion of hairs.

The reader might say that the likenesses mentioned may
perhaps be conceded, but what about the horns of the ruminants ?

(2) Well, in the Natural History Museum it is stated that ‘The
earliest known forms of Deer, those of the lower Miocene period, had
no antlers, as in the young of the existing species. In the existing
genera, Moschus and Hydropotes, there are no antlers at any time.
The Reindeer has them in both sexes, and in all others the male only.’

So we see there is a very great variation in these features, and
some existing genera among ruminants, and also among extinct
forms of Deer, are wzthout horns.

Further, let us see what the great naturalists say about horns
in the Horse.

(e) Darwin tells us,) ‘In various countries horn-like projections
have been observed on the frontal bones of the Horse ; in one case,
described by Mr. Percival, they arose about two inches above the
orbital processes, and were very like those of a calf from five to six
months old, being a half to three-quarters of an inch in length.” And
further on, Dr. Wallace says ‘That horns have not unfrequently
arisen from such apparently uncaused variations is indicated by
the remarkable difference of structure and growth in the horns of
such allied groups as the Deer and the Antelopes, which at a quite
recent epoch must have originated independently.’

1 *Are individual acquired characters inherited?’ by Alfred Russel Wallace, Fort-
nightly Review, April 1893, p. 495.
THE ONE BIG DIGIT OF THE HORSE 269

With due deference to Dr. Wallace’s great authority on these
matters, I would ask why does he say ‘That horns have not un-
frequently arisen from such apparently wscaused variations’?
They may be zzherited reversionally from some ancestral form.
Moreover, why does he think that the Deer and the Antelopes ‘ must
have originated independently’? Everything we know about
these animals tends to the conviction that they did mo¢ originate
independently. The horns of the Antelope have a core covered
with hard epidermis; while the horns of the Deer have a core
covered with velvety epidermis which is shed: the Giraffe retaining
a covering of skin on its horns ¢hroughout. In the Deer the
epidermis peels off and leaves the core zude. In the Antelope the
epidermis hardens into horn, and sheaths the horn permanently,
so that the antler of the Deer may be the homologue of the core
of the Antelope’s horn.

The remarkable part seems to be the shedding of the Deer
horns. We have, however, an analogous phenomenon in the
shedding of plant leaves, in the shedding of oak branches (Quercus
Robur), in the shedding of the arms of star-fishes.

Then taking into consideration the digestive characters of both
groups, the characters of their limbs, and the absence of incisors
from the upper jaw of both, it seems difficult to escape from the
conclusion that Antelopes and Deer are closely allied, and have
originated from a common stock.

A number of common characters in the Horse, normal and
abnormal, such as the ‘ Horned Horse from Texas,’ } would indicate
that it also is a branch of the same common stock from which Ante-
lopes and Deer arose.

(f) Then the callosities on the Horse’s legs are features which
the South American Camel-like ruminants, as I have shown else-

1 American Journal of Science, 3rd series, vol. 43, 1892, p. 344.
270 STUDIES IN THE EVOLUTION OF ANIMALS

where, still retain, and for which several other ruminants have
substituted tufts of long hair, or hair differently coloured from the
surrounding surface. Curiously enough, Grevy’s Zebra has lost
the callosities from its legs entirely, without leaving any trace of
them, while the other Zebras and the Ass have them only on the
fore-legs, and the Horse has them on all four. So that the total
disappearance of callosities in many ruminants is no evidence
whatever that their ancestors never had them. I have not seen or
heard of any mention or trace of such a feature in Rhinoceroses,
Pigs, etc., to which the Horse is supposed to be closely allied.

The ruminating apparatus of the Ox and its congeners may
appear a difficulty in the endeavour to approximate the two groups,
those of the Horse and of the ruminants; but we know that there
is a section of Monkeys which have a stomach with several diver-
ticuli, and, curiously enough, this form of stomach seems to have
some relation to the absence of cheek-pouches, as if these acted
somewhat homologously with the crop of the bird and the rumen
of the ruminant. After all, these three features are diverticuli of
the digestive tube.

We know that the Horse takes more time to masticate his food
than the Ox, and therefore does not require a ruminating organ.
It is not difficult to imagine that the ancestors of the Horse at one
time lived in a tract free from enemies, and therefore chewed their
food leisurely, and eventually got rid of the sacculated stomach,
if they previously had it; or reversely, the ancestors of the Ox were
in tracts surrounded by enemies, and had to gobble their food and
depart as quickly as possible from the feeding-ground ; then those
who did not die of indigestion gradually got into the habit of
regurgitating their food and masticating it leisurely over again.
Of course all this was not done in a week.

If one can imagine a Horse evolving out of a fish, there can
THE ONE BIG DIGIT OF THE HORSE 271

be no possible difficulty in evolving him out of a ruminant.
Palzontologists, moreover, will tell you that if you go back far
enough in time you will find that not only the Horse and the Ox,
but also the carnzvora, were mixed up in one type. Time is the
great factor needed for this evolution, and assuredly there is no
lack of it in the universe!

The question, then, finally resolves itself into this:—Is the
Horse an ‘ odd-toed’ or an ‘ even-toed’ miammal ?

The reader may now judge for himself, and furnish the reply.

Zoologists and paleontologists have done a great deal to link
the present with the past, and so have made a surer basis for the
doctrine of evolution. But Professor Huxley} gives a warning
against too hastily concluding that, decause no evidence of verte-
braté animals has been discovered in certain formations, therefore
none existed during the deposit of those formations, for in p. 88
he says casts of bones may be the sole record of animals having
existed in a formation. This means that the bones themselves
have been dissolved away, and have disappeared. If something
had occurred to disturb the cast also, no evidence whatever might
remain to show that once bones had been buried there.

At p. 90 he says—‘ From the highest animals, whatever they
may be, down to the lowest speck of protoplasmic matter in which
life can be manifested, a series of gradations, leading from one
end of the series to the other, either exists or has existed. Un-
doubtedly that is a necessary postulate of the doctrine of evolution.’

But one might ask—Where are the solid evidences of gradations
between protoplasmic matter and the higher animals? They are
only to be found at present in the human brain as zuferences
from the known available facts.

1 Lectures on Evolution—‘ Science and the Hebrew Tradition.’
MONSTROSITIES AS PROBABLE FACTORS
IN THE CREATION OF SPECIES
‘It would be well for students of extinct forms of life to enter this domain of science
without any preconceived ideas at all! It would save a great deal of confusion and
trouble in the end; and moreover would be far more truly scientific. For what right
has any one, however great his knowledge or his ability, to dictate to Nature, and to say
this or that is impossible—that no reptile, for instance, could possibly have flown; or
that such and such teeth were impossible for a reptile? . . . Facts such as those should
teach caution, and every student of palzeontology will do well to remember the saying of
Agassiz: ‘The possibilities of existence run so deeply into the extravagant, that there
is scarcely any conception too extraordinary for Nature to realise.””’

Creatures of other Days,
by Rev. H. N. HuTcHINnson, p. 73.
PARI All

MONSTROSITIES AS PROBABLE FACTORS IN THE
CREATION OF SPECIES

THE study of monstrous forms, both in the vegetable and animal
worlds, is very interesting, because, not infrequently, some important
secrets of nature are thereby revealed, which no one would suspect
from the contemplation of simple xormal forms. This study of
monstrosities has been dignified by the euphonious term of
Teratology, and elevated into a branch of the science of biology:
but I do not yet see that monstrous forms have taken their place
as dinks in the method of creation by evolution.

What is a monstrosity? Darwin says'—‘By a monstrosity I
presume is meant some considerable deviation of structure
generally injurious, or not useful to the species,’

And on p. 52, he says—‘ Under domestication monstrosities
sometimes occur which resemble normal structures in widely
different animals. If monstrous forms of this kind ever do appear
in a state of nature, and are capable of reproduction (which is not
always the case), as they occur rarely and singly,’ their preservation
would depend on unusually favourable circumstances. They would
also during the first and succeeding generations cross with the

1 Origin of Species, vol. i. p. 51.
2 We have absolutely no means of knowing that in ancient times they did not occur
in numbers.
276 STUDIES IN THE EVOLUTION OF ANIMALS

ordinary form, and thus their abnormal character would almost
inevitably be lost.’

In the case of polydactyl monstrosities Darwin himself has
shown that this is certainly not the case, the abnormality often
seeming to gain strength by a@z/ucion with the normal form, and
Professor Huxley indorsed this view.

It seems we are here dealing with words instead of with facts ;
for two metacarpal or metatarsal bones, by fusing into one bone,
become a monstrosity, although of a lesser degree, as much as if
two eyes fused into one.

We see so many teratological phenomena in man and among
domestic animals, originated somehow suddenly that there can be
no reason to doubt that in a state of nature similar monstrosities
must also have frequently occurred. The majority, no doubt,
became extinct from unfitness in the battle of life, but now and
again a monstrous individual may have been fitted, not perhaps to
carry on the same life as those which bred it, but that very
monstrosity may have enabled it to acquire a different habit of
life, which may have left it qwz¢ou¢ competitors, and so enabled
to live. Then if it bred with the others out of which it evolved,
it would sometzmes transmit the monstrosity to which it may have
owed its life, and so by degrees a new type of animals would
come into existence. Having more or less the same habits, they
would congregate together and interbreed, and thus fr that
monstrosity, so called.

Among monstrosities might be mentioned the upper canines of
the Badirusa, or Pig-Deer, which grow through the upper jaw
upwards, and curve backwards over the eyes ; and what is more, in
some varieties they seem to be quite useless, as their points almost
touch the skin ; so that instead of digging up roots, as other wild
pigs do, the Babirusa contents itself with eating fallen fruit.
MONSTROSITIES 277

Mr. Hutchinson evidently did not feel satisfied that the usual
small variations have been a/ways sufficient to account for certain
structural{ phenomena which would seem to leave unexplained
gaps behind them in the course of development. For after stating
that surroundings must have had a great deal to do with the
changes wrought on the structure of animals, he says:1 ‘ There is,
however, another cause which may be of even greater importance,
although it cannot be so easily understood—and that is znternal
changes in the animal itself. All the creatures we see around us
are constantly varying, and have done so in the past—now in one
direction, now in another. The cause of “variation” is one of the
unsolved problems of modern biology or the study of life; but we
do know that a variation occasionally happens to be of such a
kind as to make a radical change in the organism, and to fit it
for new conditions of life better than its comrades of the same
species.’ As an example of such a change he quotes the power of
‘gestation,’ ‘ whether acquired at once, by some individual, or only
slowly brought about after many generations.’

Zoologists have invented the terms ‘aberrant forms’ to denote
forms of animals which do not conform to the theory of ‘gradual
accumulation of small variations,’

Among fishes there are numerous forms which might have
originated in a sudden ‘aberration.’ For instance, there are two
forms of Sword-fish, the ordinary one (Aizstophorus), with its
upper jaw prolonged into a sword-like point; and various species
of Hemiramphius? These have the ower jaw prolonged in a sword-
like point. Both these forms may have originated suddenly in
fishes with equal jaws, either by a monstrous enlargement of one
jaw, if both jaws were small, or by a monstrous dwarfing of one

1 Creatures of Other Days, p. 178.
2 Fishes of India, by Francis Day, part iii. pl. cxix.
278 STUDIES IN THE EVOLUTION OF ANIMALS

jaw, if both jaws were originally long. Then such a monstrous
weapon having been found useful, it would increase to a certain
advantageous maximum, by constant use and direction of nervous
energy thereto. There is nothing in such a monstrosity, supposing
the abnormal size to have originated in one, to lead us to suppose
that these two fishes would have been debarred from procreating
with their norma! fellows, and perpetuating this abnormality.

Then the Hammer-headed Shark (Zygena) leads to the thought
that such an aberration may have originated monstrously by a
certain projection of both ocular regions,

Again, the extinct Dinotherium giganteum may have had its
turned-down lower jaw tusks originating in a sudden abnormal
form; and the immense upper jaw tusks of Elephas Ganesa (104
feet long, and massive in proportion) may have become so large
by an abnormal growth. Indeed it may have been those enormous
tusks which helped to cause the extinction of that particular form
owing to their great unwieldiness, and consequent disadvantage in
the struggle for life. In other words, they may have increased
beyond the maximum of usefulness.

1 In the Temple Flower Show of 1894 there was a Sedum ticketed Sedum virens
monstrosum, consisting of a fasciation of stems covered all over with small fleshy
leaves, and resembling a cockscomb (probably Sedum reflexum cristatum of Dr.
Masters). Its parent form is said to have ¢trac/zg stems. Then there was Scolopen-
drium vulgare scalariforme, said to be a monstrous form of the common Hartstongue fern.
There cannot be much doubt that sudden monstrosities of similar and other natures may
have originated zew genera.

One often sees a fusion of twin flowers producing a larger many-petalled and many-
stamened flower. There was one such in Le/um monadelphum Szovitsianunt.

Mr. Heal informed me that he had a monstrous Streptocarpus consisting of a fusion
of four flowers. He tried to perpetuate it, but its descendants reverted to the one-flower
type with five petals of the Gloxinia shape.

No doubt this obliteration of a monstrous type, and reversion to ancestral forms,
would often occur in nature, but among millions of such phenomena there might be
some which couz/d be perpetuated, and we know that six-digitate individuals can be
perpetuated 27 sfzte of dilution with normal blood.
MONSTROSITIES 279

When one reads Professor Flower’s book on The Horse, one feels
a sort of conviction that the method of creation has been modifica-
tion by very slow steps, now increasing the number and size of parts,
then diminishing them, and even suppressing them entirely, accord-
ing to the dictates of surroundings and the struggle for life and love.

When, however, one looks into Stebbing’s book on the Crustacea,
and turns up Dorippe Dorsipes, and others with two pairs of legs
on their backs, one becomes staggered, and the former ‘slow-step’
faith becomes much shaken. One then begins to think that the
method of creation may not always have been by slow steps, and
that sometimes a monstrous form turned up, which, if it could live
and struggle, and become adapted to surroundings, might become
the foundation of a race on what we would call ‘ monstrous’ lines.

Then at p. 40 Mr. Stebbing says: ‘ The theory that all append-
ages of a crustacean are either legs or modified legs will strike a casual
observer as rather strained in its application to the mandibles.
That a Crab should adapt the basal joints of a pair of limbs
for masticating its food may seem as unlikely and absurd as that
a man should have teeth on his elbows and should draw them up
in front of his lips for the purpose of biting and chewing whatever
he wished to put into his mouth. To prevent all cavilling, however,
on this point of the theory, the King Crab, Lzmmudus, is so obliging
as to ignore the ordinary mouth organs, and to use the bases of its
actual walking legs as mandibles.’

It is no wonder that anomalous legs should occur at the depths
of 3050 and 2375 fathoms (p. 19). It would be a wonder if anom-
alies did mof occur at that depth. It is a marvel that the molecules
of the ova can arrange themselves at all under that pressure.

Dr. Alfred Russel Wallace says:! ‘Herbert Spencer tacitly

1 Are individual acquired characters inherited?’ Fortnightly Review, May 1893,
p. 657.
280 STUDIES IN THE EVOLUTION OF ANIMALS

assumes that natural selection works by the preservation of large
individual variations, ‘sports’ as they are often termed; whereas
both Darwin himself, and all his followers, entirely reject these as
causes of modification of species (except perhaps in rare cases
where they may initiate new organs) and rely wholly on those
individual variations which occur by thousands and tens of
thousands in every generation.’

It may be heresy to say so, but it does not follow that Darwin
and his followers are right.

Professor W. Kitchen Parker was a follower of Darwin, yet in
his Mammalian Descent, p. 93, he says: ‘Nature does now and
then make amazing leaps, certain types taking on sudden meta-
morphorses, and in the fraction of a lifetime the low is transformed
into the high,’

And Mr. Camille Dareste, another follower of Dawrin, writes :}
‘ Aujourd’hui le plus grand probléme de histoire naturelle est
celui de l’origine des formes innombrables sous lesquelles la vie
s'est manifestée a la surface de laterre. Sice probleme est soluble,
il ne peut ’étre que par la connaissance de la tératologie et de la
tératogénie ; c’est-a-dire, par l'étude de toutes les formes nouvelles
qui peuvent dériver d’une forme spécifique primitive, et des causes
qui déterminent leur apparition,’

Dr. Wallace and others then hold to the notion that species
have come about solely by gradual accumulation of uséful charac-
ters, and only very exceptionally by what may be called ‘jumps’ ;
yet nothing seems clearer than that ‘jumps’ have occurred in the
past,—and may occur now—which, if advantageous in the struggle
for life, may have laid the foundation of new types. Nothing
is clearer than the fact that a monstrosity may be inherited, and
survive even when it crosses with normal forms; and the notion

1 Jn a Preface to M. Guinard’s Préc’s de Tératologie, p. ix.
MONSTROSITIES 281

that it must be extinguished by dilution with normal blood does
not seem tenable. ;

‘Natura non facit saltum’ may after all be one of ‘those
dogmas of Science which may be upset when we begin to perceive
that there is no good reason why nature should zo¢ make a ‘saltum.’

It is a matter of history that the doctrine of Natural Selection
was suggested in Darwin’s mind by the studies he made in the
artificial selection of domestic Pigeons and other animals; but
Naturalists seem slow to accept the suggestion which monstrous
forms in domestic animals and man would naturally lead to, viz.,
the probability that similar monstrosities in past ages may have
been factors in the evolution of animals and plants,

And the reason may be that there lingers in men’s minds a
theological bias in connection with the word ‘monstrosity. How
could a perfect God allow such a hideous anomaly to live, and
engender others like it? But if He did not allow it, how did it
make its appearance?

In the Royal College of Surgeons there is the skeleton of a
wild Cat with six legs. It was entrapped when half grown, It is
evident that it could have lived up to that age, and have struggled
successfully for its existence, and, if not captured, it mzght have
laid the foundation of a race with six legs! The extra pair of legs
are attached to the pelvis, and are evidently the only remnant of
a twin Cat.

Professor L. Agassiz seems to have had a notion that the ‘ Divine
thought, now and again, burst out into a new line of evolution, as
if it were tired of amusing itself on the old lines, and wanted to try
some new experiment.

Unfortunately for this mode of theology, the new type did not;
in most cases, cut itself off from the old lines entirely, but seemed
to be made up of the old pattern, with something new added on, or
282 STUDIES IN THE EVOLUTION OF ANIMALS

taken off, or something fused with another, so that traces of an
evolution of one type from another which may have preceded it
are in most cases evident.

Then if the Divine thought of Agassiz was not the director
of the evolution of these new types, is there any other mode of
explaining the sudden appearance of what may truly be called
monstrosities ?

The Science of Teratology has recorded a great number of
monstrosities, both in the vegetable and animal kingdoms. What
brings them about?

There seem to be two divisions of monstrosities :

(a) Fusion, more or less complete, of two separate individuals
(twins), into one compound body, with or without suppression of
some of the parts ; and

(6) Fusion of different parts of the same individual ; separation
of originally united parts; displacement or suppression of various
parts; or re-appearance of some ancestral character, by what is
called reversion (atavism) ; or enlargement or diminution of a part.

We know that in the fully formed individual the nerve-centres,
with their communicating nerves, control everything. Every
function of the body is controlled by them. It is reasonable there-
fore to infer that, during embryonic development, as soon as the
nervous system has had a commencement, it must begin to control
the evolution of every part of the body ; and the slightest change,
from whatever cause, from the normal that may occur in the nerve-
centre, or prime-mover, is likely to be reflected as a modification
Jrom the normal at the distal end of the nerve or nerves which
that nerve-centre controls. A very slight change in the embryo
may result in much more extensive changes in the fully formed
animal.

It would appear a not uncommon thing for the controlling
MONSTROSITIES 283

nerve-centres to produce wzsymmetry of the two sides. And one
can imagine that a slight difference in the circulation of the two
halves of the nervous system might cause this want of exact
symmetry.

The examination of the two sides of spotted and striped
animals, such as those of Figs. 4 and 22, will convince any one that
a mathematical symmetry of both sides of an animal, if it occurred
at all, must be rather the exception than the rule.

Professor Flower has stated that in the Cetacea, even the two
hands may have a different number of bones

In the Royal Natural History, vol. ii. p. 143, there is the
description of a very interesting phenomenon, because evidently
rarely met with. The writer says: ‘One of the two known skulls
of Ross’s Seal is peculiar in that, while on one side the first upper
cheek-tooth, and both the corresponding lower teeth, are imper-
fectly divided by a vertical groove, on the opposite side of the
upper jaw the place of this tooth is taken by two complete single
teeth. Hence it is obvious that we have here a case where an
originally single tooth divides into two distinct but simpler teeth.

This serves to show how the numerous simple teeth character-
istic of the toothed Whales may have been derived by the splitting
up of teeth originally composed of three distinct cusps, like those
of the Leopard Seal, each cusp of such tooth forming, as we shall
see, a distinct tooth in the Whales.’

The writer mentions other peculiarities in the teeth of the Grey
Seal on pp. 134, 135.

All this is very instructive, not only because it shows us that
on one side of the same jaw there may be simple teeth, while on

1 “Sometimes the different sides of the same animal are not precisely alike, either
in the arrangement or even the number of the carpal ossifications.’—Osteology of
Mammals, p. 301.
284 STUDIES IN THE EVOLUTION OF ANIMALS

the other there may be compound teeth, but also because there
may be a ‘ reverse’ to the phenomenon described, viz., that a large
complicated tooth, such as we see in certain mammals, may be a
Suston of a number of szmple teeth! And this is exactly what may
have happened, either suddenly, or by slow steps, when a long jaw
with many teeth passed into a short jaw with few teeth. Some of
the teeth may have been suppressed, but a number may have
become fused into one large compound tooth.

We do not know what influences and controls the disposition
of the parts defore the nerve-centres of the embryo are formed. It
does not follow, because there are yet no nerve-centres and
nerves, that therefore there is not something that controls the
cells and acts as a means of communication.

Anyhow, when in the animal embryo the nervous system has
once taken form, we cannot have much doubt that it controls and
regulates the progress of the embryo. Its controlling influence in
the multiplication and disposition or arrangement of the body
cells, which are increasing by fission, may be likened to the
controlling influence of the battery or dynamo in electro-plating.
The two processes would appear to be parallel. We do not know
why some metals are deposited in a compact form, suited to
electro-plating, and why some are deposited in dendritic or tree-
like forms. All we know at present is that they do so. And all
we can say of monstrosities is that they do occur during the
evolution of the embryo, although from recent experiments in
artificial teratogeny we may hope at no distant period to learn
something more definite about the intimate causes of monstrosities,

Some might say—‘ This may be an ingenious stretch of thought,
which would somewhat explain aberrations in azzmals; but what
about analogous aberrations in plants? We have no nervous
system there.’ No, but ‘nervous system’ may be only words
MONSTROSITIES 285

intended to give cover to our ignorance. We call nervous system
an apparatus consisting of nerve-cells and nerve-filaments, Plants
may not have this, but they may have some tissue—unlike nerve-
tissue—which functions as communicator of change-impulses to
distant parts. At all events we must infer that Drosera, Dionea,
and others, possess some means of sending messages from one
part of their body to another. Lauffen in Switzerland is a long
way from Frankfort, yet recently an influence of a dynamo at
Lauffen was transmitted to Frankfort, a distance of one hundred
and eight miles, with the greatest ease, although in this case also
there was no nervous apparatus to do it!

It would seem that disturbances may occur either in the cells,
before the nervous system is traced out, or after, in the grey matter
of nerve-centres. Professor V. Horsley shows that these centres
with their characteristic nerve-cells and nerve-fibres are developed
very early in the embryo.

New types may have had their genesis during embryonic life,
while great disturbances in geological periods were going on, and
which may have been due to external physical causes acting on
the contents of the ovum.

Sir J. William Dawson? says: ‘In the Appalachian region of
America we have the carboniferous beds thrown into abrupt folds,
their shales converted into hard slates, their sandstones into
quartzite, and their coals into anthracite, and all this before the
deposition of the Triassic Red Sandstones which constitute the
earliest deposit of the great succeeding Mesozoic period.’

This seems evidence enough of the commotion caused by
volcanoes and shrinkage, and the changes induced by heat’and
chemical substances.

At p. 176 he further says: ‘At the close of the Permian

1 Brain and Spinal Cord, p. 190. 2 Geological History of Plants, p. 175.
286 STUDIES IN THE EVOLUTION OF ANIMALS

and the beginning of the Trias, in the midst of this transition
of physical disturbance, appear the great reptilian forms char-
acteristic of the age of reptiles, and the earliest precursors of the
mammals, and at the same time the old carboniferous forms of
plants finally pass away to be replaced by a flora scarcely more
advanced, though different, and consisting of pines, cycads, and
ferns, with gigantic Equiseti.’

A little exercise of the imagination will enable us to compre-
hend that in those volcanic periods, both the sea and the atmo-
sphere may have had gases and other ingredients in them which
might either kill, or strangely modify, the development of the ova
and seeds on which they acted. Heat, electrical changes, and
continual tremors of the earth and sea, may have also been factors
in the modification of both animal and vegetable embryos. We
know what strange modifications of buds and other parts of plants
are produced by even the tickling of the minute larva of a Gall-Fly.

In our present comparatively quiet times, with a settled and
steady composition of atmosphere and sea, we may have difficulty
in conceiving and measuring the amount of modification that may
have occurred when the conditions must have been wholly different.

We should not forget, however, that, although not generally
admitted, the action of changes in the environment in modifying
forms, already established elsewhere, is of importance.

Some species no doubt are very plastic and can easily change
their form under changed conditions; others do not, while there
are some that are killed outright.

At a lecture of the Royal Horticultural Society, Mr. Burbidge
mentioned that Megenthes Raja, from Borneo, cannot be grown
in this country under artificial conditions, even with the skill
and scientific manipulations of Messrs. Veitch and Sons.

1 See Mature, vol. 43, p. 581, for change of species in Arvabis anachoretica.
MONSTROSITIES 287

When I visit the Fish Gallery of the Natural History Museum
I feel a sort of conviction that many of the strange forms around
me must have commenced as monstrosities.

The saw of the Saw-Fish (Prisdzs) seems on the face of it to
have been a monstrosity; the Spoonbill Sturgeon (Polypodon
Spatula); the curious nose-process of Callorhynchus antarcticus, the
tailless Orthagoriscus oblongus, the enormous dorsal fin of one of
the Sword-fishes, Histophorus gladius, and so forth—all convince
me that these strange forms very probably commenced by a sudden
monstrosity. Wt is amongst fishes that we meet with such startling
abnormalities in large numbers. Scientists try to explain the
stump tail of a Puppy by calling it an ‘arrest of development.’
That would mean that, ‘it is what it is’! Any boy in the street
can tell us that such a Puppy ‘has not a long tail, like other Dogs!’
But what is the cause of the arrest ? ;

Mr. Stebbing in his Crustacea mentions that the male of
Gelasimus avenatus (De Haan) has one cheliped (claw), right or
left, monstrously enlarged. The very fact that it is sometimes the
right, and sometimes the left, which is so enlarged, would tend
to show that it is not by slow degrees that it attains that size, but
by some sudden derangement in the right or left nerve-centre that
controls the growth of the cheliped, and the Crab has to make the
best use of it.

Monstrosities being congenital might easily be inheritable more
or less, provided the reproductive organs were efficient. So this
monstrosity in a certain Crab may become the fixed feature of a
whole race, which originally may have commenced by a sudden
evolution in ove generation, and not by slow and gradual accumula-
tions of some slight variation. The study of fishes and crustacea
would seem to afford quite a revelation, as to the probable origin
of many species.
288 STUDIES IN THE EVOLUTION OF ANIMALS

One cannot look at the drawings of fishes, even of a restricted
region, such as that of India, by Francis Day, without feeling that
monstrous forms must have been generated among fishes in plenty.
Agassiz, in the account of his Journey in Brazil, gives us a
striking tale of the zznumerable species of fishes he and his
assistants discovered in the Amazon and its tributaries.

If experiments in teratogeny be worth anything, they will
certainly modify our notions of the origin of species, solely by slow
accumulation of some mute variation. Just think of it; the
ovum segments into two and then into four cells, and so on. If
any injury should occur to any one of these cells, from whatever
cause, the result may be a monstrosity. The wonder is that we
are not all monsters! We say heredity keeps us straight; we
might also say it keeps us crooked, to allow for variations; but
when these statements are translated into common language they
seem to spell— we know nothing about them’!

A little more atomic disturbance here, a little less there, during
the embryonic stage, may produce a mew compound, which then
may be called a species, a genus, or even an order, as the case may
be. Naturalists may think they have discovered a// the species in
a district, but new ones may be naturally manufactured now and
then, just as the chemist produces new compounds by manipulating
and acting upon old ones.

There cannot be much doubt that the action of the nerve-centre,
in co-operation with the vaso-motor nerves which affect the
nourishment of parts, may cause the degeneration, atrophy, and
eventual suppression of an organ.

Let us suppose, for instance, a Dinosaur of the ordinary kind,
with fore-legs sufficiently large to enable it to move on all-fours,
say, like a Kangaroo. Let us suppose again that by a sudden
monstrosity the fore-limbs were dwarfed to the size of those of Cerato-
MONSTROSITIES . 289

saurus' It is evident that if the animal lived, it would be forced
to walk maznly on its hind-legs, and balance itself by its huge tail.
It is also evident that the continual use of the hind-legs alone would
strengthen them, and at the same time weaken the fore-legs ; and
this might go on till the fore-limbs became suppressed altogether,
as in Hesperornis regalis; and as the hind-limbs have been sup-
pressed in the Round-headed Dolphin and in other Cetacea. If
the fore-limbs can be suppressed altogether at once, as in some
cases of human monstrosities, they certainly can be dwarfed all
of a sudden.

Abnormalities are revelations that cannot be ignored. They
indicate to us one possible method, by which important large and
sudden variations may have been effected.

Then, when a large and sudden variation occurs in the brain
itself, we call the possessor of it either an imbecile, or a lunatic,
or a genius. If the latter, he may be a prophet, a philosopher,
a poet, a scientist, a mechanician, an inventor, a saint, etc.

As long ago as 1829, Isidore Geoffroy St. Hilaire? mentioned
the artificial production of monstrous birds by acting in various
ways on the eggs, and he said that artificial incubation gives rise
to more monstrosities than natural incubation. And at p. 71 he
stated that the history of human monstrosities has frequently been
traced to blows on the abdomen during gestation.

Some better and more accurate idea may be formed of the
possible origin of variations, anomalies, and monstrosities—all
indicating different degrees of disturbance during embryonic life—
from the recent experiments of Roux, Dareste, Windle, Hertwig,
Driesch, Chabry, and others.’

1 Shown on p. 125 of Creataures of Other Days.
2 Propositions sur la monstruosité, p. 70 (Zi héses de la Faculté de Médecine, No. 185).
3* Experimental Embryology,’—by Mr. J. A. Thomson, Natural Science, April
1893, p. 294.
T
290 STUDIES IN THE EVOLUTION OF ANIMALS

All students of embryology know that the ovum, in developing,
divides into two cells, then into four, then into eight, then into six-
teen, and subsequently into a number of cells called a‘ morula,’
and further on a‘ gastrula, after which the embryo begins to take
shape.

By these experiments it has been shown that ‘the germ is
plastic in the grip of its environment, and various malformations
have been induced which are of interest to the student of mor-
phology’; that ‘there is now good evidence to prove that these
disturbing agents act, at least in the majority of cases, on that part
of the developing organisation which is concerned with the forma-
tion of the vascular system of the embryo’ ;1 that ‘of the first two
cells into which the egg of a Frog develops, one has in it the
material for forming the right half of the body, the other has in it
the material for forming the left half of the body.’ It was proved
that ‘one of the first two segmentation cells may form half an
embryo, that it can develop apart from its neighbour, and that
either a right or a left half-embryo might be produced, as well as
an anterior or posterior half’; that, quite lately, Roux has been able
to rear an entire Frog embryo from half an egg’; in experiments
on ova of an Ascidian, Chabry found that ‘by destruction of one
of the cells into which the ovum first divides, the remaining cell
develops into a half-larva, and if two anterior cells of the four-
celled stage be destroyed, a posterior half-individual results’; that
‘on to the sixteen-cell stage at least, each cell has a determined
destiny, and represents a definite part of the embryo, and that if
one of these sixteen cells be destroyed, the defect (or monstrosity)
in the larva is a definite one’; that ‘while Roux got half-embryos
from half an egg, Driesch got half-sized, but otherwise complete

1 Surely the vascular system is under the control of the servows system, or of some
electrical influence which corresponds to it, before the regular nervous system is
developed.
MONSTROSITIES 291

embryos from half an egg’; that Mr. Edward B, Wilson of Columbia
College, New York, ‘has produced out of one egg of Amphioxus,
twins of half the normal size, and by varying the experiments,
a sort of Siamese twins from one egg were produced.’!

A number of other experiments on ova are mentioned by Mr.
Thomson, and the conclusions he has come to from this review are
that :

(1) There is a great deal of life in an egg; three-quarters, a
half, or a quarter of an egg will, under favourable conditions, form
a complete larva.

(2) There is no little plasticity in the germ; the segmentation
may be profoundly altered, the shape of the young embryo may be
greatly changed, and a new type of larva may be produced, yet the
inherited characteristics are strong, for the experiments show a
marked tendency in the germ to reach a normal result by an
abnormal path.”

With regard to the non-inheritance of acquired characters, he
says: ‘How many ova are there which float in the sea, and in other
media; these are now, as similar ova have been in the past,
exposed to the influences of very complex physical and chemical
conditions. That their living stuff may be greatly affected the
results of experimental embryology show. It is likely that the
same is true in Nature’s great laboratory, and the results, being
germinal, may be transmissible. We need not be in haste to
exclude the direct influence of the environment from among the
primary factors of evolution.’

1 Tf all this can be established, it may go a long way towards demonstrating that our

two halves were originally a fusion of ‘wo embryos with szppression of a.right and left
half of each.

2 Perhaps the embryo may be likened to a crystal ; you may break a crystal in pieces,
and each piece, under proper conditions of food and stimulus, will grow again into a
crystal like its parent,
292 STUDIES IN THE EVOLUTION OF ANIMALS

We may be on the eve of momentous revelations concerning
not only the appearance of monstrous forms among human beings
and domestic animals, but also concerning the sudden appearance
of new types of animals in geological periods on monstrous lines |
These artificial ways of evolving monstrosities may yet be able to
teach us how the long tail of the Archeopteryx may have been
reduced zz one generation to the short tail of the modern bird, or
vice versa ; how the long tail of one kind of Monkey may have been
reduced in one generation to the stump of other kinds, and to the
diminutive tail of Man; how the many digits of the Ichthyosaur
may have been suddenly reduced to the five digits of the Plesiosaur,
or of some other ancestor of the numerous tribe of five-digited
animals.

‘We must not forget, says Agassiz,! ‘that we are the lofty
children of a race whose lowest forms lie prostrate within the
water, having no higher aspiration than the desire for food; and
we cannot understand the possible degradation and wretchedness
of Man without knowing that his physical nature is rooted in all
the material characteristics that belong to his type, and link him
even with the Fish.’

Changes in the cells of the ovum during segmentation,
changes after the embryo became differentiated through disturb-
ance of the controlling nervous and vascular tissues, might at any
time have given rise to what is called a monstrous form, which if
unfit would die out, but if fit might endure and transmit its
monstrous form.

It would all depend upon whether the monstrous form could enter
into sexual union with the normal forms. In the case of most
fishes, however, even this would not be needed, and the facility
with which the sperm cell can reach the germ cell in these low

1 Life and Work, by Dr. Charles F. Holder, p. 189.
MONSTROSITIES 293

vertebrates, may be the reason why so many strange monster-like
forms are found among these animals,

It might be thought incredible that a monstrous form could
pair with a normal form. It would all depend, as I said, upon
whether the sperm cell of the one could be made to reach the
germ cell of the other. By artificial means Messrs. Veitch and
Son have succeeded in mating a Lela with a Sophronitis—two
forms of orchids which no botanist would have conjectured are
mere variations of the same species |

This is not all, for Professor Agassiz? says, ‘I remember to have
found in the neighbourhood of. Mobile (U.S.), no less than six new
species in the course of an afternoon ramble. These fishes are
almost all viviparous, or at least lay their eggs in a very advanced
state of development of the young? The sexes differ so greatly
in appearance that they have sometimes been described as distinct
species, nay, even as distinct genera (Wolinesia and Pacilia). We
must be on our guard against a similar mistake.’ v=

If husband and wife of these fishes can be so distinct as to be
described as distinct species and genera, and s¢d// pair, what wonder
would it be if monstrous forms, produced by disturbing influences
which may have occurred during the first stages of embryonic
development, should be able to pair with their normal progenitors,
although, may be, quite distinct in anatomical characters?

At one time there was a dogma among biologists that animals
of different species could not interbreed, as, if they happened by
some chance to interbreed, their progeny was barren. It was
thought perhaps that some providential law ruled matters thus, in
order to prevent the mixing of species. But now it seems to be

1 The variations of type in the Fishes of the Amazon, noted by Professor L. Agassiz,
are simply zznumerable. 2 Journey in Brazil, pp. 32, 33-
3 He does not mention how their ova are fertilised.
204 STUDIES IN THE EVOLUTION OF ANIMALS

admitted that Goats and Sheep, Rabbits and Hares, common
Fowls and Pheasants, Pheasants of different species, Tigers and
Lions! Zébras, Asses and Horses do interbreed, and several of them
produce fertile hybrids. The question is—What is a species ?

What possible influence in ancient times could have caused a
disturbance in the development of ova so as to evolve abnormal
forms, say in fishes, as evidenced by the vast number of new types
linked by some characters, and yet unlinked by others, with their
forerunners. Several causes suggest themselves, viz. :—-

(a) Submarine volcanoes heating the water and diffusing new
chemical compounds dissolved in it.

(0) Shakings and concussions of the water and of the sea bottom.

(c) Electrical discharges connected with submarine volcanic
explosions, and so forth,

I shall now discuss some human monstrosities to see how far
such a fotion as I have foreshadowed in the foregoing lines has
any basis in fact.

Cases of supernumerary digits in Man are by no means rare.
Darwin? states that ‘Dr. Burt Wilder® has tabulated the cases of
152 individuals with supernumerary digits, of which 86 were males,
and 39, or less than half, females ; the remaining 27 being of un-
known sex.’

Then ¢ he says that ‘ supernumerary fingers and toes are emin-
ently liable, as various authors have insisted, to be inherited. Poly-
dactylism graduates by multifarious steps, from a mere cutaneous
appendage, not including any bone, toa double hand. But (p. 458)
an additional digit, supported on a metacarpal bone, and furnished
with all the proper muscles, nerves, and vessels, is sometimes so

See Mature of 27th April 1893, p. 607, on Lion-Tiger hybrids.
2 Descent of Man, p. 223.

3 Massachusetts Medical Society, vol. ii., No. 3, 1868, p. 9.

4 Animals and Plants under Domestication, vol. i. p. 457.
MONSTROSITIES 295

perfect (note this) that it escapes detection unless the fingers are
actually counted; occasionally there are several supernumerary
digits, but usually only one, making the total number six. This
one may be attached to the inner or outer margin of the hand, re-
presenting either a thumb or little finger, the latter being the more
frequent. Supernumerary digits are more common on the hands
than on the feet, but generally both hands and both feet are
similarly affected.’

Mr. Darwin adds that ‘the presence of a greater number of
digits than five is a great anomaly, for this number is not normally
exceeded by any existing mammal, bird, or reptile. Nevertheless,
supernumerary digits are strongly inherited ; they have been trans-
mitted through five generations, and, in some cases, after disappear-
ing for one, two, or even three generations, have reappeared through
reversion, These facts are rendered, as Professor Huxley. has
observed, more remarkable from its being known in most cases that
the affected person has not married one similarly affected,

In such cases, the child of the fifth generation would have only
one-thirty-second part of the blood of his first sex-digitated ancestor.
Other cases are rendered remarkable by the affection gathering
force, as Dr. Struthers has shown, in each generation, though in each
the affected person married one not affected;! moreover, such
additional digits are often amputated soon after birth, and can
seldom have been strengthened by use. Dr. Struthers gives the
following instance: ‘In the first generation an additional digit
appeared on one hand; in the second on both hands; in the third,
three brothers had both hands, and one of the brothers a foot,
affected ; in the fourth generation all four limbs were affected,
Dr. Struthers however asserts that cases of non-inheritance are
much more frequent than cases of inheritance.

‘ Note this, The affection gathers force even when diluted with normal blood.
296 STUDIES IN THE EVOLUTION OF ANIMALS

Six digits have also been observed in negroes as well as in
other races. Also in hind-foot of a Newt, and in hind-feet of
several generations of Cats.!_ In several breeds of Fowl the hinder
toe is double, and is transmitted truly.

Dr. J. W. Ogle gives a case of inheritance of deficient phalanges
during four generations.”

Mr. Darwin gives references for all he states.

What we have particularly to remember is that monstrosities,
although diluted with normal blood, (2) may zncrease in number in
subsequent generations, and (4) may spread from the hands to
the feet also.

From this we may infer that the disturbing influence in the
hand nerve-centre, which causes the monstrosity in that limb, is
liable to diffuse itself along the spinal cord and influence the
nerve-centre of the foot also.

A-few detailed cases will impress on the reader’s mind not only
this sex-digitate feature in Man, but also the ferszstence with which
it may be inherited, although diluted by normal blood.

Godehen in 1751 recorded the oft-quoted history of one Grezio
Calleja, a polydactyl® He had six fingers and six toes in each
limb. He had four children, three boys and one girl. The eldest
boy, Salvator, had six digits in each limb, but the supernumerary
digit in the hands was not so well formed as those of the father.
On the contrary those of the feet were better formed. The other
three children had the normal number, five, in both hands and feet ;
but all excepting the youngest had deformities of fingers more or
less marked. So only one of the four children of Grezio had
normal limbs. The children of this latter were normal. On the

1 Brit, and For. Med. Chirurg. Rev., April 1872.

° J. T. Cunningham, translator of Eimer’s Organte Evolution, says he has a Cat with
six toes on every foot.

3 Hist. des Anomalies, by Isidore Geoffroy St. Hilaire, vol. i. p. 699:
MONSTROSITIES: 297

contrary, Salvator had two boys and one girl sex-digitate, and one
‘boy normal. Grezio’s second son George (who was normal) had
three sex-digitate daughters, and one normal boy; and Grezio’s
daughter (who was also normal) had two boys and one girl normal,
and one boy sex-digitate.

Dr. Prosper Lucas! gives the case recorded by Maupertuis.
“Jacob Ruhe, surgeon of Berlin, was born with six digits in his
hands and feet, inherited from his mother Elisabeth Ruhen, who
inherited this abnormality from Elisabeth Horlsmann. Elisabeth
Ruhen transmitted it to four children out of eight. The father
was Jean Christian Ruhe, who was normal. Jacob Ruhe, one of
the sex-digitated boys, married Sophie-Louise de Thingen, a normal
woman, and had six children, two of the boys being sex-digitate,’

Renow recorded several sex-digitate families, who from time
immemorial were spread over several] parishes of Bas-Anjou.
These abnormalities were perpetuated in spite of the alliance of
the abnormal individuals with families of normal conformation.
The abnormalities were transmitted indifferently to either male or
female children. It was also established that a normal child of an
abnormal parent can again give birth to an abnormal child.

Dr. Prosper Lucas (p. 327) quotes some much more interesting
phenomena. He says that Vanderbuch collected records of
a Spanish family where this abnormality was often complicated
with the following: ‘In the majority of the members of this
numerous family, the third and fourth digits? of the hand were
united by the integument throughout their length. The phalanges
of such double fingers were almost all composed of double bones,
situated side by side. The nails, although of one piece, had a

1 Hérédité naturelle, vol. i. p. 326.
2 Exactly those that form the fused metacarpal bone of the Ox and its congeners.
In the marsupials this is a common feature. :
298 STUDIES IN THE EVOLUTION OF ANIMALS

vertical furrow; what indicated that they were in origin two
fingers was that the tendons (“epicondylo-sus-phalangetticus, et
cubito-phalangetticus communis”) were also double. In some
individuals of this family the thumb was biphalangian, and among
these the extremity of the digit was sometimes bifurcated. In
other individuals the two portions which formed the digit were
united throughout as in other digits.’ What is still more curious
is that in some individuals the third and fourth toes were similarly
bound up in one integument.

Vanderbuch counted forty individuals of this Spanish family in
whom some abnormalities of digits existed. Almost all were healthy.

A race of Cats is mentioned? with six digits on each foot, the
peculiarity having been inherited to the tenth generation.

Then M. Guinard? quotes the case of a Bitch with six digits,
which transmitted this feature to almost all its young ones. He
also quotes Lenglen, who gives a case of a sex-digitate Man, whose
descendants, up to the sixth generation, all presented this feature.
He winds up by saying—‘ Everybody knows the history of that
Arab tribe of the Foldi, whose children are all born with twenty-
four digits. The members of this tribe are very numerous, and do
not ally themselves with other tribes. They consider this feature
absolutely constant, so that when by chance a woman gives birth
to a child with five digits, she is considered to have committed
adultery, and her child is not acknowledged by her husband.’

And finally (p. 131) M. Guinard writes—‘ Mais en face de ces
faits, nous comprenons, sans l’admettre cependant, qu’on ait pu se
demander si le chiffre 5, adopté comme représentant le nombre
normal des doigts, n’est pas un peu arbitraire, et s'il n’a pas existé
des individus ayant normalement six doigts.’

Well may M. Guinard ask whether the archetypal five-digited

1 Royal Natural History, p. 427. ? Précis de Tévatologie,’ p. 130.
MONSTROSITIES 299

limb is not a little arbitrary! Y read M. Guinard’s Précs after I
had been long contemplating the possibly fictitious archetypal
hand and foot which characterise so many animals,

If by archetypal we only mean a type of animals with five
digits which is very ancient, then the term is admissible enough, for

 

Fic, 92.—(¢) Right hand of an Ichthyosaur, pl. 23, Book of the Great Sea-Dragons, by
Thomas Hawkins ; (4) Right hand of /. Chiropolyostinus, digital portion—pl. 7 of same work.

as low down as the Plesiosaurs, and may be much lower, we already
find the five-digited type established.

Where could this abnormality of sex-digited animals have
come from? Why the five-digited type was so early established
we do not know, but we do know that the Ichthyosaurs, which
cannot be denied relationship to-other vertebrates, had as many as-
eight digits (Fig. 92 (6)); while 7 Chiroligostinus (pl. 3 of Hawkins’
300

STUDIES IN THE EVOLUTION OF ANIMALS

Great Sea-Dragons), had only three complete digits, and a
dwindling fourth in both hand and foot.
All we can say is that mammals? may have started from a

     

—
=
aK

w
vata r=
aor

<s

FIG. 93.—Left hand
of Plesiosaur, pl. 27,
Book of the Great Sea-
Dragons, by Thomas
Hawkins.

branch of the great vertebrate series in which
the abnormality of five digits (we now call this
normal and archetypal) had already become a
fixed character, and not impossibly the abnormal
hands of the Plesiosaurs, with a reduction to
only five digits (Fig. 93), and also of their close
relatives, the existing Dolphins, may have been
the monstrous foundation of the whole race of
animals with five digits. We cannot for one
moment suppose that in the Ichthyosaur the
humerus, radius and ulna are the homologues of
the same bones in mammals, and at the same
time declare that the carpal, metacarpal, and
phalangeal bones of the same Ichthyosaur are
not homologous with bones of the same name in
mammals !

Well, some Ichthyosaurs have seven digits
and a dwindling eighth. What has become of
the sixth, seventh, and eighth digits in mammals?

The answer is, that not impossibly they
have been suppressed in past geological times,
as a deformity in the first instance, and after-

wards inherited as a xormality ; that is, if mammals ever descended

from animals like the Ichthyosaur.

Not only have three digits

been suppressed, but also a number of phalanges, and the whole
carpus, ulna, radius, and humerus have been vastly modified.

1 Is there any good reason for supposing that Ichthyosaurs were 7of mammals ?
2 See figure of Round-headed Dolphin in Flower’s Osteology of Mammals, p. 302.
MONSTROSITIES 301

In this connection it is interesting to note that in the York
Museum there is a unique Plesiosaur. It is ticketed PZ. Zet-
landicus (Phillips) from the Lias of Lofthouseynear Radnor. It
has a much shorter neck and a much
larger head than the ordinary Plesio-
saurs. It may be one of the transition
forms between the Ichthyosaurs and
the Plesiosaurs. Its large head is not’ ;
unlike that of an Ichthyosaur. It is the Sea pail is
only example known of this species. of the right manus (dorsal aspect)

; of Water Tortoise; dAZammals, by

Then let us compare fora moment Flower and Lydekker, p. 48.
the carpal and metacarpal bones of
certain animals. In the Water Tortoise we find two regular
rows of carpal bones, of five bones, in each row, each’ meta-
carpal bone articulating with only one of the carpal bones, as
shown in Fig. 94; while in the hand of the Plesiosaur (Fig. 93)
we find the carpal bones reduced, and huddled up in two irregular
rows, the metacarpal bones articulating quite differently from
those of the Water Tortoise, although the number of metacarpal
bones is the same in both animals.

 

ww

Such a difference in the disposition of the carpal bones, and in
their articulation with the metacarpal bones, in these two animals
may have occurred gradually, but there is no good reason why it
could not have occurred suddenly by a process which we would
now call monstrous, or, to use a Scientific term, ¢eratological.

There is one other great conclusion to be drawn from the study
of the records of sex-digitate men and women. In spite of their
marrying individuals in whose families no such abnormality
occurred, sex-digitation, as we have seen, persistently appeared
among their descendants, so that the notion which some
evolutionists hold, viz. that a variation which may suddenly
302 STUDIES IN THE EVOLUTION OF ANIMALS

appear becomes soon extinguished by mixing freely with normal
types, would seem to be erroneous. For sex-digitation, instead
of being eliminated by dilution, in many instances becomes
strengthened, Moreover, the supposition that oe monstrosity
occurring in a species has no chance of survival must be greatly
modified when we know that a whole litter of puppies can at once
appear with stump-tails,) and that almost all the puppies of a sex-
digitate Bitch were born with a similar feature. It is evident that
there would be ample opportunities for these similarly affected
animals to zz¢erbreed, and further fix and perpetuate a monstrosity,
even if we did not know that, in some cases, dilution with normal
blood will zo¢ wipe it out.

Many other monstrosities besides sex-digitation have been
transmitted to descendants. That quoted by M. Guinard on p.
162? is a most curious one. A male Guinea-Pig was kept for a
long time in the laboratory of the Veterinary School of Lyons. It
had no sign of eyeballs, although the orbital cavities were well
formed. After death, it was found that there was no trace of
optic nerve, and the foramen for its passage did not exist.
Otherwise this anomalous Guinea-Pig was healthy and vigorous,
and it lived fora long time. It was kept among normal female
Guinea-Pigs, and had numerous children. Among them were found
six which, like the father, had no eyeballs! M. Guinard adds :

‘M. Desfosses a démontré que cette conformation des organes
de la vue est normale chez le Protée.’

Hairlessness of the body is found ‘normal’ in the hairless race
of Chinese Dogs, but it has also occurred anomalously in the Horse,
the Ox, and the Dog. Even Birds have been met with which had
no feathers, So that we begin to suspect that the hairlessness of

1 [ have known of two Bitches, in different countries, which gave a whole litter of
puppies with stump-tails. 2 Précis de Tératologie,
MONSTROSITIES 303

Man may have occurred a// of a sudden as a monstrosity, and then
may have been inherited and perpetuated! If hairlessness of
body happened to carry with it a correlative development of the
brain, with superior intelligence, the hairless race would have
eventually killed out the hairy ones. And now we get the hairy
Ainos, either as reversions, or as vestiges of a character which
probably was normal in remote times, the Burmese hairy family,
and the Russian ‘homme chien,’ being atavic anomalies,

That the nervous system has a great deal to do with hairiness
is shown by the case quoted by M. Guinard (p. 155)? of a woman
whose trunk became hairy during each pregnancy, and lost its
hairy coat in the intermediate periods.

This is analogous to what happens in animals when a change
of season and other external conditions, acting on the nerve
centres, bring about a change of coat and plumage.

Isidore Geoffroy St. Hilaire considered that the indispensable
condition for the transmission of a monstrosity is that the re-
productive organs should be intact. Who can tell how many
monstrosities which have occurred in geological periods had
answered to this condition ?

M. Guinard (p. 19)” says :—‘ Ce ne sont pas les anomalies graves
qui se transmettent le plus souvent, mais les simples vice de
conformation.’

This is only natural, for if the ‘anomalies graves’ affect the
organs of reproduction, there can be no chance of their being trans-
mitted. It is perfectly conceivable that anomalies, which in
geological periods could not be inherited, died out with the
anomalous individuals. These, for all we know, might have been
numerous, and in cases where only ove fossil anomaly is traceable

1 The Vahgans of Fuegia are hairless, and wear no clothes. They are exposed to the
cruelest of climates, and yet donot become extinct. Their extreme sensitiveness to slight
warmth is testified to by Darwin, 2 Op, cit.
304 STUDIES IN THE EVOLUTION OF ANIMALS

it may possibly have been a monstrosity which was of trans-
missible.

All malformations connected with the extremities of the limbs
are hereditary and are easily transmitted from generation to
generation. This is a well-established fact, and proved by numer-
ous and well-authenticated examples. But M. Guinard and others
have shown that other anomalies, as long as the reproductive
organs are efficient, are also frequently inherited, such as hairiness
in man, hairlessness in other animals, hornlessness, want of eyeballs,
etc. If the anomalous individual cannot procreate, the anomaly
must die out with the individual possessor of it.

Fishes lay an enormous number of ova. Supposing that some
external influence were adequate to modify the development of ove
fish-embryo, it would be undeniable that a Jaxge number of ova
might be s¢multaneously and similarly modified.

We have known an anomalous influence to pervade a whole
litter of puppies ; and the probability is that an anomaly of struc-
ture might occur in a whole litter of fishes, which might mean of
thousands! Therefore we must begin to look upon monstrosities,
both now and in the past, suddenly appearing in a type, from what-
ever cause, as possible factors in the origin of species)

1 In order to impress this important idea on the reader’s attention, I will quote a
parallel case from the Vegetable Kingdom. Among market gardeners there is a MWyosotis
(Forget-me-not) with almost every flower having many more petals than the typical
Myosotis, which has only five petals. Most of the fowers have eight or nine petals, and
many have ten, which is exactly dowd/e the typical number. The sepals and stamens
correspond with the number of petals, so that there can be no doubt that the ten-petalled
flowers are fusions of two whole flowers, the fusion occurring while they are in their
embryonic stage. The ova/ centre of many such flowers plainly indicates a fusion of two.
It should be understood that in this form of AZyosotzs it is only the individual flowers
which are monstrous. I have ascertained that the ovules contained in the nucules round the
base of the conical style, are, many of them, fertilised, and Professor Henslow has it from
the grower, Mr. Appleton of Longford, that 80 per cent. of its seeds produce this par-
ticular monstrosity, although insects must frequently cross-fertilise it with pollen of the
typical form, which now and again appears on this monstrous plant, and which-also may
MONSTROSITIES 305

No evolutionist can doubt that an anomaly or monstrosity—
(a) if it be viable ; (0) if it has its reproductive organs in a sufficiently
fit state; (c) if it be inherited—svay lay the foundation of a new
species, new genus, new order.

That anomalies and monsters are sometimes viable, that some-
times they have their reproductive organs in a fit state, and that
their features are frequently inherited—are sufficiently shown by the
facts quoted.

Whether a new species or genus in its initial stage can hold its

be grown in the vicinity, the Forget-me-not being a very popular plant. The origin of
this particular monstrosity is not known. What we have to note is that the whole plant
is pervaded by this monstrous influence, and that it is reproduced through the seed.

There are two other varieties of monstrous J/yosotis which have come under my
notice. That called ‘The Jewel,’ which was issued by Messrs. Carter and Son in
1893. I have only seen a picture of it. Not only is each flower a /wston of two flowers,
but the flowers are gathered into a compact head (cafétulum) somewhat like that of a
Scabious, or the double Corn-flower of gardeners. This additional monstrosity is declared
to come true from seed.

Then in the Gardeners’ Chronicle of 8th August 1891, p. 159, to which my attention
has been called by Professor Henslow, there is a third monstrous form of A/yosotis, called
Victoria. It isa sort of ‘hen and chicken’ form, all the chickens have flowers which are
fusions of two entire individuals of the typical five-petalled form, and the hen in the
centre appears to be a fusion of about five distinct flowers. Messrs, Ernst Benary of
Erfurt sent it out in 1886, and it is presumed that it sprang from AZ. alpestris robusta
grandiflora (Eliza Fonrobert). It comes true from seed. But the curious fact connected
with this particular form is this: It appeared in the garden of Mr. W. Marshall at
Bexley, who states that he did not receive seeds from either Germany or anywhere else.
It is hardy in severe winters. The stem isas thick as a Swan quill, compressed and hollow
in the interior, characters which are indicative of a fusion (fasciation) of many separate
stems. The drawings in the Gardeners’ Chronicle are taken from a specimen exhibited
by Mr. Marshall, and the editor says :—‘It is reproduced from seed, and is now known
to have occurred during several years, and possibly may have originated spontaneously
in a garden at Bexley, as well as in Germany.’

It may perhaps be questionable whether in this monstrous A/yosofzs the ten-petalled
flowers are a fusion of two separate flowers while in their embryonic stage. We know
that ove ovum in certain animals is capable of developing twins, and possibly the ovule
of a plant may sometimes do so likewise. I consider the ovule as a bud, and the flower
as the development of a bud ; so that I can see no objection to the idea that a bud could
under certain circumstances develop twins parthenogenetically. This hypothesis might
account for the fower-buds of this AZyosotés developing into fused twins.

U
306 STUDIES IN THE EVOLUTION OF ANIMALS

ground in the battle of life is a totally different question. This
may depend on conditions of the environment. Among fishes we
have seen that there are great facilities for the sperm cell to reach
the germ cell, and that large numbers of individuals might possibly
inherit an anomaly in one generation. This would make the result
of the struggle for existence quite different from what it would be
if only ove in a generation inherited the anomaly.

There is no good reason why the species or genus, originating
in a monstrosity, should not in various cases be better able to
struggle for life than the type of its progenitors. It would all
depend on the means of offence and defence, or the means of
obtaining food and of resisting adverse influences.

Palzontologists declare that in past ages it was a common
phenomenon for a new type to appear, to increase to a maximum,
and then gradually disappear, to be replaced gradually by a new
type, which in turn followed the same course, to be replaced by a
subsequent and more vigorous type. The appearance of a viable
and inheritable monstrosity that was better equipped for the
struggle of life may possibly account to some extent for this
succession of type after type, to go through the same process
of increase, decline, and final extinction.

Man, with his monstrous intelligence (not unfrequently with his
monstrous foolishness) has killed out and is killing out a number
of types, and is replacing them with his own type. What will be
the upshot of all this process remains to be seen.

Professor Louis Agassiz wrote :1 ‘However long and frequent
the breaks in the geological series may be, in which they would fain
bury their transition types, there are many points in the succession
where the connection is perfectly distinct and unbroken, and it is
just at these points that ew organic groups are introduced without

Footnote to p. 188 of Dr. Charles F. Holder’s Z. 4gassts—Life and Works.
MONSTROSITIES ood 307

intermediate forms to link them with the preceding ones? (Italics
are mine.)

Let us take for instance the case of only one character—that
of horns. Horned animals may have originated in the first
instance as a monstrosity. We find that in the Reindeer both
male and female are furnished with horns, In the Eland (Oveas
Canna) Mr. Selous says the horns of a female were longer than those
of a male with the longest horns,! but usually in other ruminants,
if horned, the female has shorter and more feeble horns. Then
we have species in which the female has no horns at all, and finally
we have a race of domestic cattle, arising suddenly as a monstro-
sity, in which both male and female are hornless, and so are
Camels, the Musk Deer, and some others. We have no idea how
in these animals the suppression of horns may have come about, if
their ancestors ever had them.

The appearance of new types in geological times wethout inter-
mediate forms must have been a very puzzling feature in the study
of evolution, both to Agassiz and to ordinary Darwinians. Can it
be possible that the sudden appearance of monstrosities, which did
not become extinguished by crossing with typical forms, may have
had something to do with these puzzling phenomena?

Professor Alleyne Nicholson, in the Swiney Lectures of 1893,
told us that both in the Old and New World, in the Old Tertiary
beds, a large number of quadrupeds appear a// at once without any
predecessors, that is, ancestors from which according to the doctrine
of evolution these new quadrupeds could be reasonably considered
to be descendants.

This is not all. For accompanying this new inroad of un-
accountable animals there was an inroad of plants, Between the

1*The longest pair of Eland Bull horns I have seen measured 2 ft. 6 in. in length,
the longest pair of Cow horns 2 ft. 10 in. —A Hunter's Wanderings in Africa, p. 206.
308 STUDIES IN THE EVOLUTION OF ANIMALS

upper and lower chalk, the Cycads, which previously were very
abundant, now become less and less, and higher groups of plants,
all highly specialised, take their places.

In this connection Sir J. William Dawson! says: ‘We have a
great and sudden inswarming of the higher plants of modern types
at the close of the lower Cretaceous. In relation to this, Saporta,
one of the most enthusiastic of evolutionists, is struck by this
phenomenon of the sudden appearance of so many forms, and
some of them the most highly differentiated of dicotyledonous
plants. The early stages of their evolution may, he thinks, have
been obscure and as yet unobserved, or they may have taken place
in some separate region, or mother-country as yet undiscovered, or
they may have been produced by a rapid and unusual multiplica-
tion of flower-hunting insects! or it is even conceivable that the
apparently sudden elevation of plants may have been due to
causes still unknown. This last seems, indeed, the only certain
inference in the case, since, as Saporta proceeds to say in
conclusion: “ Whatever hypothesis one may prefer, the fact of the
rapid multiplication of dicotyledons, and of their simultaneous
‘appearance in a great number of places in the Northern Hemi-
sphere at the beginning of the Cenomanian Epoch, cannot be
disputed.”’

Quoting from Dr. Newberry,? Sir J. W. Dawson at p. 205 says:
‘But the most surprising discovery yet made is that of a number
of quite large helianthoid flowers, which I have called Palganthus.’
It seems probable that the composite formed a part of the
Cretaceous Flora. Dr. Newberry adds: ‘No composite flowers
have before been found in the fossil state, and as these are among
the most complex and specialised forms of florescence, it has been

1 Geological History of Plants, p. 193.
? Bulletin of the Torrey Botanical Club, March 1886.
MONSTROSITIES 309

supposed that they belonged only to the recent epoch, where they
were the result of a long series of formative changes,’

Now I have always thought that composite flowers may have
originated from some ancestral monstrosity—a disc-like fascica-
tion of some plant of the nature of Pzmelea, [xora, Bouvardia
Valeriana, Centranthus, and others,! and here is a helianthoid mass
of flowers appearing all of a sudden in the Cretaceous flora—with-
out any apparent predecessors to explain its gradual evolution!
May it not have been the development of a monstrous form
appearing suddenly like the composite-like MZyosotzs (The Jewel)
mentioned before, which came out of the ordinary AZyosotzs with a
scorpioid inflorescence ?

Professor Nicholson said that the most rational way to account
for this new creation, so to speak, is to suppose that in the Pacific
Ocean there was a continent which sank, slowly it may be, and is
now no longer traceable, so that the animals which had been
there evolved had time to migrate in two directions, to what we
now call the Old and the New Worlds. Thezr predecessors are
now under the sea, and therefore this theory, unless that continent
should come up again, is not likely to be confirmed.

These new quadrupeds, although specialised, had still a general-
ised structure, and were all five-digited in hand and foot. In the
Early Tertiary, asa rule, they had that number of digits, and then a
diminution in their number commenced, such as in the Hippo-
potamus, the Rhinoceros, the Ruminants, and finally the Horse,
which has only one digit. Concurrently with the reduction of digits
there occurred a reduction in the number of teeth from forty-four
to thirty-two in Man, the latter being now reduced to twenty-eight.

There was another feature connected with these new quad-

1 The reader should note that the disposition of the florets of the disc of several com-
posite flowers is sfz7a/, as it often is on an ordinary raceme.
310 STUDIES IN THE EVOLUTION OF ANIMALS

rupeds. In the Early Tertiary both the fangs and crowns of their
teeth were short, and as they progressed their teeth became longer,
so that their lives became longer also, as their teeth did not wear
away so quickly. Moreover, the Early Tertiary quadrupeds,
although of large size, had small brains, and this condition was
also conducive to a short life, for in the struggle for existence the
animal with a large brain has always been able somehow to circum-
vent the one with a small brain. The early types had no horns.

There seems to me two weak points regarding this theory of
a sunken continent in the Pacific Ocean.

(a) If highly specialised types existed on this Pacific continent,
what prevented their migrating defore that particular time? Was
it the zsolatzon of the continent? If so, when it began to sink it
would become zzore isolated! Of course it may be said that the
continent was not wholly isolated, but in some place connected
with other continents by a neck of dry land such as that which
connects Africa with Asia: and that when a portion of this lost
continent began to sink, that is, when the grazing or feeding
grounds of those animals began to be swallowed up by the sea,
and their numbers continuing undiminished, hunger forced them
either to die or to migrate by some land communication. There
is, however, another and a weaker point in this theory.

(6) Concurrently with the appearance of a new type of quad-
rupeds in the New and Old Worlds there appeared a new type of
plants. From the previous Cycads, which are rather fern-like, we
pass, without any local predecessors, to plants, which are more or
less like those we have zow, that is, flowering plants.

We now know that a large number of seeds of flowering plants
can be transported long distances by strong winds and cyclones,
and even on the mud that sticks to the feet of water-birds and
waders, and in some cases on their feathers also.
MONSTROSITIES 311

If these flowering plants existed on this lost continent, one
does not quite understand how their seeds could have been pre-
vented from getting disseminated to both the Old and New World
before this supposed migration took place. One can understand
that a certain number of seeds went over with the animals attached
to their hair, but what could have prevented the migration of seeds
before the migration of animals from this lost continent? This is the
part of the theory that would seem to require some explanation.

Then Dr. Alfred Russel Wallace seems to insist that no great
changes in the continental and oceanic configuration have occurred.

There is another point of importance in this discussion. ‘It
is a remarkable phenomenon,’ says Sir J. William Dawson,! ‘in the
history of genera of plants in the Mesozoic and Tertiary, that the
older genera appear at once in a great number of specific types,
which become reduced as well as limited in range down to the
modern. This is, no doubt, connected with the greater differentia-
tion of local conditions in the modern ; but it indicates also a law
of rapid multiplication of species in the early life of genera.’

What is the cause of this rapid multiplication of species in the
early life of genera?

From what we know of heredity, it is a great controller of
form, and therefore in those days there must have been some
efficient disturber of heredity, Teratogeny may yet throw light on
this puzzling question. Hybrids between two genera are certainly
not unknown in modern horticulture, and hybrids between two
species are common enough; and it is not impossible that a large
proportion of this puzzle may be due to words. The older
botanists may have given generic names to forms which were no
more distinct, phystologically, than what we now call varieties. It
seems to me that the theory of a sunken Pacific continent in no

1 P, 222, of. cit.
312 STUDIES IN THE EVOLUTION OF ANIMALS

way explains the ‘remarkable phenomenon’ of ‘rapid multiplication
of species in the early life of genera.’ It is not impossible that in
those days what we would call species and genera may have been
more readily hybridisable, and by steady change of conditions and
consequent physiological differentiation, up to modern times, the
process of xatural hybridisation may have become more difficult
and rare.

Professor Huxley? says: ‘In former periods of the world’s
history there were animals which overstepped the bounds of
existing groups and tended to merge them into larger assemblages.
They show that animal organisation is more flexible than our
knowledge of recent forms might have led us to believe; and
that many structural permutations and combinations of which the
present world gives us no indication may nevertheless have existed.’

This seems very natural, for the further we go back in time the
less inheritance the species may have had at its back, and there-
fore the less time there may have been for the creation of a fixed
habit of the nerve-centres in animals, which regulate everything.
Consequently they would be more variable. On the other hand,
the further we go forward in time, the more the habit of inheritance
would become confirmed, and therefore the more fixity of characters
would ensue. The ofduess of the inheritance would then have
made it ¢oo strong to admit of much change, unless man interfered
with the natural process by artificial selection.

Professor Huxley (p. 89) warns us not to be in a hurry to
conclude that because no organic remains are found in a deposit,
that therefore ‘animals or plants did not exist at the time it was
formed, for he has known fossil remains guzée dissolved away,
leaving no trace but the casts which formerly surrounded them.
It might so happen that even the casts might be destroyed.

1 Lectures on Evolution—(Science and Hebrew Tradition), p. 102.
MONSTROSITIES 313

The unfortunate thing is that in all these questions we try to
evolve theories with an insufficient number of facts to build upon.
For it cannot be said that either the geology or the palzontology
of our earth is a// known.

We do not know yet whether a teratological form simulating
a totally different type from that of its immediate progenitor is
possible. All our present knowledge tends to show that heredity
would restrict a great deviation from the normal type.

Darwin and his followers, in order to get over this difficulty,
supposed that there was no such thing, now or ever, as zdentecal
heredity, and that every new being varied in some way from its
progenitors. Therefore there can only be heredity wzth variation,
as wesee it among domestic animals. And as these variations may
be very small, the great differences we see in animals is accounted
for by the accumulation of small differences, whenever useful, over
long periods of time, through natural selection. There may have
been many intermediate forms between the present types, but
these have become extinct in the struggle for existence, or from
other causes.

M. Guinard! says: ‘Il est impossible de séparer variation et
anomalie, car en sens vrai du mot, la variation est toujours une
anomalie.’

I would add that it is impossible to separate either from
monstrosities. For if we are to classify as simple variations the
absence of the tail in a Dog, or of horns in an Ox, why not other
monstrosities ?

‘Pour ces raisons, he continues, ‘nous ne séparerons pas, dans
notre étude, la variation de l’anomalie, qui sont l’une et l’autre des
déviations du type spécifique,’

On p. 7, however, he seems to put aside all this logic; for he

1 Précis de Tératologie, p. 5.
314 STUDIES IN THE EVOLUTION OF ANIMALS

says: ‘A case of polydactylism in the Horse, or of double uterus
in a Woman, or of prolongation of the tail in Man, must be con-
sidered as a simple return to an ancestral type, that, is vever-
stons—anomalies, as far as the individual case is concerned, but
not concerning the speczes to which it belongs (!)’

One would like to ask—Is there any law which limits re-
versions? If a polydactyl foot in a Horse is a reversion to the
pentadactyl foot of some ancestral form, why is not sex-digita-
tion in Man a reversion to something like the octodactyl hand
of the Ichthyosaur ?

M. Guinard appears to me to lay too much stress on what he calls
specific type, as if there were any truth in the antiquated dogma that
specific types are unchangeable and are not modifications of some
other pre-existing types. If supernumerary mamme in a Woman,
and horns in a Horse, are reversions to conditions existing in other
species, it appears to me that there is no good reason for supposing
that reversions can go, not only beyond the species, but beyond
the genus, and the order too, for it seems to me that artificial sub-
divisions in the flow of what we call ‘vital energy’ are as artificial
as a classification of the different portions of a waterfall would be!

Dr. Wallace, in Darwznzsm, p. 101, says: ‘On comparing the
variations which occur in one generation of domestic animals with
those which we know to occur in wild animals, we find no evidence
of greater individual variation in the former than in the latter.’

I suppose by variation he means the ordinary small variations
which are peculiar to every individual; for on p. 100 he refers to
monstrosities only with reference to artificial accumulations of
something beautifully novel, strange, or amusing. Some of these
artificial monstrosities would be injurious, such as the tumbling of
Pigeons. In his work on Darwznzsm 1 cannot find that Dr.
Wallace even suspected that a new type of animal or plant smgh¢
MONSTROSITIES 315

be founded on a monstrosity appearing suddenly, and in another
place he rejects this idea.

M. Guinard finds that he cannot make any icine between
a variation and an anomaly, and I find myself unable to make
any distinction between variation, anomaly, and monstrosity. They
are only degrees of the results initiated congenitally during
embryonic development, under different conditions of physical
surrounding. The latter may give rise to a new type suddenly,
provided it is viable and reproducible ; the former may give rise to
a new type by gradual accumulation of a variation in a certain
direction. It seems to me that we must have them doth as
factors in the origin of species.

Dr. Wallace’s own observations of certain facts in nature can only
be explained by initiation as monstrosities, and not by gradual
accumulation of minute variations under adaptive conditions. In
his Travels on the Amazon, p. 58, he says: ‘ What birds can have
their bills more peculiarly formed than the Ibis, the Spoonbill, and
the Heron? Yet they may be seen, side by side, picking up the
same food from the shallow water on the beach ; and on opening
their stomachs we find the same little crustacea and shell-fish in them.
So of the fruit-eating Pigeons, Parrots, Toucans, and Chatterers.’

It has been assumed by some writers on Natural History that
every wild fruit is the food of some bird or animal, and that the
various forms and structure of their mouths may be necessitated by
the peculiar character of the fruits they are to feed on; but there
is more of imagination than fact in this statement ; the number of
wild fruits furnishing food for birds is very limited, and birds of the
most varied structure, and of every size, will be found visiting the
same tree,

Is not all this clear evidence that it is mo¢ always the habit of

1 See Fortnightly Review for May 1893, p. 657.
316 STUDIES IN THE EVOLUTION OF ANIMALS

the animal which gradually adapts its structure to surrounding
conditions, but that somedzmes a monstrosity may occur which
with an abnormal structure must either adapt its habits to its
surroundings or must cease to live? Those monstrosities which
can succeed in adapting themselves to surrounding conditions live,
and reproduce themselves, to startle and puzzle us with the fact
that so many strange and abnormal structures are suited to
identical habits! And so we have Ibises, Spoonbills, and Herons,
among Waders, leading the same life; and Pigeons, Parrots,
Toucans, and Chatterers, among frugivorous birds, leading also an
identical life among trees.

There seems no reason for doubting that a monstrous in-
dividual, having found its monstrosity wsefué in the battle of life,
would acquire in some cases habits consonant with the monstrous
limb or limbs, and we might be misled by thinking that the
anomalous structures were brought about by the habits gradually
modifying the structure, while the exact reverse may, in many
cases, have happened, just as an athletic man would take to athletic
habits Jecause his muscles were originally well developed.

That new habits, to which organisms may have been driven,
may be engendered by slow and minute steps of variation in
structure may be too true, but this in no way excludes the great
probability that many new and monstrous variations, as we
would now call them, may have originated zz one great and sudden
step,’ improving afterwards if the individual were viable and
reproducible. That anomalous structures are often supplied with
not only bones, but also muscles, vessels, and nerves, as if they
were inherited, and ready equipped for use, is sufficiently proved
by the supernumerary digits. In many cases, both structurally and
functionally, these could not be distinguished from the normal ones.

1 Professor W. Kitchen Parker thought so also (Mammalian Descent, p. 93).
MONSTROSITIES 317

No one who gives, this subject any attention can look over
Mr. Stebbing’s Aizstory of Crustacea, and also the specimens in the
Natural History Museum, without becoming convinced that many
of them must have originated suddenly as monstrosities, brought
about by some atomic disturbance, during the development of the
embryo, and that subsequently natural selection may have further
modified the monstrous parts, the animal having found them
useful in the battle of life, or at all events found that they did xot
seriously interfere with its continued existence.

Look at that unfortunate Dorippe japonica of Fig. 10 (Stebbing’s
Crustacea). It descended from ancestors that had ezgh?t fully
developed walking legs, but Dorippe has only four walking legs,
and the other four are ludicrously dwarfed and stuck on its back.
In the Natural History Museum there is a specimen ticketed D.
dorsipes! Then look at the figures on Plate vii. Every one of the
specimens has either one pair or two pairs of atrophied legs, just as
if you saw an adult Man with a normal body and two little ‘wee
legs’ at the end of it, like those of a newly born baby.

Stebbing says: ‘To account for their dorsal position various
reasons have been suggested. Herbst says the Crab can run
either way up! Another view is that these hind-legs lift foreign
objects on to the carapace, and a third, that they help to repel
animals that might otherwise tread’on the Crab’s back.’

Whatever may be the use the Crab makes of them now, the
dorsal legs are best explained as having originally been brought
about as a monstrosity, which the animal had the good sense to
make the best use of, if it had to exist at all.

The curious part of it is that, with all its anomaly and sup-
pression of four legs from the function of progression, Dorippe has

1 I suppose, when it gets tired of running one way, it throws itself on its back and
runs on the other way, so that it can tire out its enemies ! :
318 STUDIES IN THE EVOLUTION OF ANIMALS

a wide range, and includes several species. Dorippe facchino is
found both in the Mediterranean and at Hong-Kong. There is
no good reason to suppose that two such monstrosities could xot
have originated zmdependently ;1 although it is conceivable that the
ova, in past ages, may have been somehow carried from one place
to the other, especially when we know that there is geological
evidence that the Mediterranean Sea in past geological times—
Paleozoic, Mesozoic, and even Tertiary—communicated with the
Indian Ocean across north Arabia and also with the Bay of Bengal
across north India.?

‘Facchino’ in Italian means ‘ porter,’ and the specific name may
have been given in allusion to the supposition of its using its
dorsal legs like arms to carry loads!

A writer in Chambers’s Journal for November 1890, on ‘Jungle
Notes in Sumatra,’ p. 663, says: ‘These Hornbills are very remarkable
birds. I cannot imagine any system of natural selection which
could have developed those preposterous-looking beaks. Was it
because those with the largest beaks could best defend their
families against Monkeys and Snakes? But what size of beak did
they start with? If they were so persecuted a race, would not
their enemies have exterminated them before they had time to
develop their weapons? You cannot, I suppose, allow less than
five thousand years for the process, and if they had to begin with
a beak the size of a Fowl’s, the Monkeys alone would “wipe them
out” in ten years.’

There are many kinds of Hornbills in existence, commencing
from that with a bill not larger than that of a small Toucan, to

1 Mathematicians might tell you that the chances of two identical forms having
originated independently are as ‘infinity to one.’ But is thisso? How many crystals
of this system, or of that, acquire the same geometrical form, although they originated

independently, and are made up of different elements?
2 Fragments of Earth Lore, by Professor James Geikie.
MONSTROSITIES 319

that of the Great Hornbill. In some the crest on the upper
mandible is small. It is quite conceivable that the crest enlarged
gradually up to a certain point, and that by a sudden monstrous
enlargement it reached the size we see on the mandible of the Great
Hornbill.

Then there is Toccus elegans and Toccus Montieri; which have
enormous bills like those of the Great Hornbill, but without a trace
of the monstrous crest. The Condor has a crest on its upper man-
dible not unlike that of the Hornbills.

Mr. F. W. Headley? writes: ‘The Hornbills are a puzzle. The
extreme shortness of the hand bones, a ridiculous anticlimax
following upon so grand an ulna and so portentous a humerus,
might suggest that they were once better flyers, and that the wing
is slowly undergoing reduction. But the mountainous beak seems
to show that colossal bones aré an ancient heritage of the family,
and that even feeble flight might have been difficult had they not
become hollow,’

From this it would seem that Mr. Headley would suggest that
the immense beak of the Hornbill was inherited from some ancestor
with a colossal body, but this does not touch the origzn of the
immense crest, seemingly useless, on the upper mandible of the
Great Hornbill. As these birds are frugivorous, this colossal bill
would seem to be rather a nuisance among the branches of trees.

There can be little doubt that in the course of evolution an
occasional monstrosity, as a sudden large variation, would facilitate
the interpretation of such vagaries in nature and of many a diffi-
cult problem in evolution.’

1 Proc. Zool. Soc. 1865, p. 86.

2 ©The Air Sacs and Hollow Bones of Birds,’ Matsral Science, No. 21, vol. iii.
p- 352, Nov. 7, 1893.

3 The extinct Pterodactyls had iinmense bills, not unlike those of the Hornbills, and
among ¢hem we may yet find this ancestry of the massive bill of the Hornbills !
320 STUDIES IN THE EVOLUTION OF ANIMALS

The evolutionary osteologist who may be still wedded to the
theory that every type of animal xecessarzly came out of another
type by slow and gradual modifications, accumulated by natural
selection, so as eventually to bring about a marked difference be-
tween the two, may still be hoping that future paleontological
discoveries may bring to light all the intermediate links. He may
obtain more links than he possesses now, just as he possesses
graduated links between the various existing Cats and Dogs,
Pigeons and Fowls.

But even if the whole of the geological formations of the earth
were explored, I should not anticipate that he would find all the
links he may hope for. Teratology plainly indicates that ‘leaps,
without much trace of graduated intermediate links, can occur now,
and therefore most probably similar leaps were not uncommon in
the days when the physical conditions of life must have been far
less equable than we now know them.

It would be curious if the study of abnormalities should give
us an insight into the origin of what we call zormadlzties.

Mr. J. A. Thomson! writes: ‘Among back-boned animals we
recall the teeth of the Shark, and the sword of the Sword-Fish, the
venomous fangs of Serpents, the jaws of Crocodiles, the beaks and
talons of Birds, the horns and hoofs of Mammals. Now we do not
say that these and a hundred other weapons were from their first
appearance weapons, indeed we know that most of them were not.
... By sheer use a structure not originally a weapon became
strong to slay.’

Just so; and the sudden appearance of a monstrous part would
produce one of two results:

(a) Either it would have no appliances of muscles and nerves
to utilise it in the struggle for existence, and then it would be

1 Study of Animal Life, p. 34.
MONSTROSITIES 321

rather.an encumbrance and a disadvantage, and its posséssors
might soon become extinct ; or

(4) It would have appropriate nerves and muscles ; and then
its owner would soon learn to make use of it for its own advantage,
and being.congenital it would be inherited.

We have seen that supernumerary digits may be either simple
appendages of the skin, without phalanges, muscles, or nerves ; or
they may be as well furnished with all three, and indistinguishable
from other digits. A savage born with hands and feet like those

  

Fic. 95.—Monstrous hand and foot from Axomalies de l'Organisation, by Isidore
Geoffroy St. Hilaire, vol. iii.
shown in Fig. 95, would indubitably have more power in both than
another born with hands and feet like those of Fig. 96, or perhaps
than others born with the ordinary number. And so of other
monstrosities which may have occurred in geological times, and
which may have had their monstrous parts furnished with means
for using them as weapons either of offence or defence, or for main-
taining their hold on their surroundings.

We have little knowledge as to the process by which some
cells of the embryo turn into muscles, others into nerves, and so
forth. All we know is that after the egg has subdivided itself into a

x
322 STUDIES IN THE EVOLUTION OF ANIMALS

certain number of cells, it begins to take shape, and layers are
formed ; some cells forming muscle, others, nerves, and so on, and
ultimately completes a creature like its parents, and this likeness
we call heredity. But we know also that sometimes the regular
process is disturbed, and monstrous forms are the result, and tera-

 

Fic. 96.—(a) First and fifth digits of foot; (6) Ring and little finger of hand: from
Anatomie Pathologique, Tom, 2, Livrais. 38, Pl. 1, of Cruvelhier,
togenetic investigations may one day tell us something more
definite about the genesis of such monstrosities.

It is curious that most Darwinians infer a great deal regarding
the past, from what has gone on in domestic Pigeons, and very few
infer anything regarding past phenomena of evolution from the
abnormal and monstrous forms which occur in man and in domestic
animals !

To conclude: however reluctant we may be to admit it, I believe
we shall have to admit that small and gradual accumulations of
variations do not cover the whole phenomena before us, and that
occasionally large and extraordinary variations may have occurred
in the past, which we would now call monstrosities ; and that they
may have at times laid the foundation of a new order of progress.

When once a viable individual with a reproducible monstrosity
MONSTROSITIES 323

occurred, it would almost inevitably follow that more nervous
energy would be directed to it from generation to generation by
use, 2f z¢ could be used, and it would increase in size until it reached
a maximum, beyond which it would become a drawback in the
struggle for life. Such a drawback must, I surmise, have happened
to the extinct Elephas Ganesa, with his enormous ten-feet tusks.
It must be plain also that if the tail-coverts of the Peacock were
to become twice or thrice their present length, they would become
an encumbrance and a disadvantage to the bird. The long nose
of the Elephant, the immense horns of the extinct Irish Deer,
the sword-shaped upper jaw of the Sword-Fish, the turned down
lower jaw tusks of the Dinotherium, and many other similar
extraordinary phenomena in animals, may have started as
monstrous features, all of a sudden, zx one generation, and may have
afterwards become strengthened and larger by use. To be more
scientific, we shall call these ‘jumps’ or ‘sports’ in the evolution of
animals ‘teratological variations, so that the believers in the
gradual accumulation of small variations as the so/e method of
evolution may not be shocked.

It has been a wonder to me why Dr. Wallace and other
Darwinians ignored or rejected such a palpable help to the doctrine
of evolution, as the fact that monstrosities do occur, would afford.
This doctrine requires the support of every known fact, whether
that of minute accumulated variations, through many generations,
or that of a large variation produced all of a sudden. There is
evidence to show not only that such large and sudden variations,
at one birth, do occur, but that they are reproduced, and are not
always obliterated by crossing with normal forms,

If you reject what palpably ought not to be rejected, you

1 Gordon Cumming records a tusk 20 feet 9 inches long! See Royal Natural History,
vol. ii. p. 546.
324 STUDIES IN THE EVOLUTION OF ANIMALS

increase the difficulties of accounting for the whole phenomena
of evolution. ;

In a recent and remarkable inaugural address, at Oxford, by
the President of the British Association, Lord Salisbury stated
that mathematicians do not grant the time of ‘many hundred
millions of years’ for the transformation of a Jelly-fish into a Man.
‘Lord Kelvin limited the period of organic life upon the earth to a
hundred million years ;’ and Professor Tait further cut down the
time from a hundred to ten million.

Without admitting that these mathematicians, like the Pope,
are zxfallible, and without admitting that any particular Jelly-fish
was ever converted into a Man, it is evident that if monstrosities,
or, in other words, /axge and sudden variations, were admitted as
possible factors in the creation of species, by the method of
evolution, the time needed for the transformation of the lower into
the higher organisms would be much curtailed. A writer in the
Saturday Review of 11th August 1894, commenting on Lord
Salisbury’s address, says: ‘But are the demands of the two parties
(physicists and biologists) necessarily as incompatible as Lord
Salisbury seems tosuppose? If the passage from the condition of
a protozoon to that of a vertebrate, in the case of an individual, can
be accomplished in a very few months, is it so certain that similar
changes have always been so extremely slow in the history of a
race?’
GENERAL CONCLUSIONS
‘I am convinced that any student of the subject who will cast aside his books—
supposing that they have not already bred a habit in his mind of seeing only ‘‘ in accord-
ance with verbal statement ”’—and go directly to nature, to note the actions of animals
for himself—actions which, in many cases, appear to lose all significance when set down in
writing—the result of such independent investigation will be a conviction that conscious
sexual selection on the part of the female is not the cause of music and dancing perform-
ances in birds, nor of the brighter colours and ornaments that distinguish the male.’

The Naturalist in La Plata, by W. H, Hupson, p. 287.
GENERAL CONCLUSIONS

IF the reader has been kind enough to read carefully through the
foregoing pages, he will be, I feel sure, bewildered with the mass
of diction that I have placed before him, and with the numerous
references that it has entailed.

To endeavour to quiet his brain, and relieve him of that
chaos of impressions which I have been trying to make on his con-
volutions, and in order to convince him of the truth of what I said,
as I am myself convinced, I will gather up all the threads of my
discourses into some General Conclusions.

From the evidences before me it has become my belief that:

(a) The rosettes of the Jaguar and Leopard are pigment-pictures
of ancestral calcareous armour, which consisted of bone-rosettes ;
and that the markings of these Cats are the closest resemblance
we have left to this sort of inheritance. In other mammals
modifications of ancestral rosettes have been very great, so that
the vestigial rosetting is now in many cases hardly recognisable ;

(6) In the Jaguar and Leopard, these original picture-plates
have been mazntained by natural selection, while in others, their
disappearance has been brought about, more or less, also by
natural selection ;

(¢) Among the ungulates, the dappled Horse, the Zebu, and
the Giraffe are the nearest resemblances we now have to the
original ancestral picture-plating, and that all other markings,
whether spotting or striping, as in the Cats, are modifications of
dappling or rosetting ;
328 STUDIES IN THE EVOLUTION OF ANIMALS

(@) Many mammals which have lost all vestige of rosetting
have still retained vestiges of ancestral carapacing, that is, a
picture-vestige of dorsal armour and ventral wxarmour, such as still
exist in Armadillos and Pangolins, and that the contrasts of colour
between the dorsal and ventral surfaces mean that the ventral
surface lost its armour ear/zer than the dorsal surface, and there-
fore its hair had time to differ in coloration from the dorsal surface
which lost its armour at a later period ;

(e) The contrasts of colour that we see so frequently in’ the
muzzle, round the eyes, on the hands and feet, of so many mammals
mean the same thing, viz., that those parts lost their armour before
the rest of the body, and had time to differ in coloration, after the
hair replaced the armour of those parts. Time, of course, has ‘often
obliterated all these contrasts of coloration, and in many cases has
substituted a uniform self-colouring ;

(f) The Rhinoceros has passed through similar stages. The
Rhinoceros Sondaicus carries still the plates of its Armadilloid
ancestor, while the Indian Rhinoceros has vestiges of ancestral
calcareous plating in its hide-knobs. In some cases the Indian
Rhinoceros is only partially knobbed, but Sir J. W. Flower! gives
one of this species kuobbed all over, taken from a photograph of an
animal living in the Zoological Society’s Gardens ;

(g) Judging from the very numerous mammals that are either
rosetted, or spotted, or striped, or have ringed tails, or have
contrasts of colour between the upper and lower surfaces, it seems
probable that @/ existing mammals, including marsupials, de-
scended from armoured ancestors ;

(2). The callosities on the legs of the EHguzde, and of some
ruminants, seem to be vestiges of leg glands secreting some
odoriferous substance which, smeared on long grass as the animals

1 The Horse, Fig. 9.
GENERAL CONCLUSIONS 329

moved about, enabled them to track their associates ; certain other
ruminants have lost these skin glands, and, instead, have vestiges
of them, shown by tufts of hair contrasted in colour and length
with the surrounding surface ;

(z) There is suspicion that the one big digit of the hand and
foot of the Horse was in origin doudle, like that of the ruminants.
In the latter, the two metacarpal and metatarsal bones fused into
a ‘cannon’ bone, the phalangeal bones remaining separate; while
in the Horse the metacarpal and metatarsal, avd the phalangeal
double bones, fused into single bones throughout the series. There
is some evidence to show that the Horse is more closely related to
the ruminants than he is to the Rhinoceros ;1

(7) As monstrosities occur now, they may, with greater reason,
have occurred in past ages. If this be admitted, it will be seen
that a much shorter time can be allowed for bringing about great
modifications in the species of the present and the past times than
would be needed by slow and gradual accumulation of minute
variations, which is the theory accepted by most biologists.”

1 Since writing these conclusions, I cameacross Mr. Bateson’s Afaterials for the Study
of Variations. In Fig. 120 he gives a ‘solid-hoofed’ Pig, with the iii, and iv. digits
fused into ove large digit throughout, like that of the Horse.

2 Mesoplodon Layard? is a beaked whale, with only two strap-like teeth. Professor
Moseley, of the Challenger, observes that ‘these two teeth in the adult animal become
lengthened by continuous growth of the fangs into long curved tusks. These arch over
the upper jaw or beak, and, crossing one another above it at their tips, form a ring round
it and lock the lower jaw, so that the animal can only open its mouth for a very short
distance. . . . How the animal manages to feed itself under these circumstances is a
mystery. . . . That these enormous teeth can be of no possible advantage to their owner
appears perfectly clear ; and they must probably be regarded as affording an instance of

semi-monstrous development analogous to the one displayed by the tusks of the Babirusa.’
—Roy. Nat. Hist., vol. iii. p. 35-
APPENDICES
‘It adds very much to the interest with which we regard them, if, by studying the
general causes to which they are due, we can explain their origin, and thus to some
extent understand the story they have to tell us, and the history they record.’

a Beauties of Nature, by SR J. LUBBOCK
(Configuration of Valleys).
APPENDIX A

IN addition to those mammals which are given in the preceding pages, the
following outline drawings of badly mounted specimens in the Natural History
Museum will give the general reader some idea of the number of widely
differing animals which are either rosetted, spotted, blotched, or striped in
various fashions. Some have only a vestige of ancestral markings.

The names and colours are taken from the Natural History Museum. The
colours from age are likely to become faint.
334 STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 1. Hybrid cub of Lion and Tigress, Light fawn, striped brown.

 

No, 2.—-Ocelot (fe/is gardalis), Light fawn, with brownish rosettes.
335

APPENDICES

 

Fawn, with black rosettes and brown centres.

No. 3.—Felis macroura,

 

Light brown, spotted and streaked black.

—Marbled Cat (Felis marmorata).

No. 4
336

STUDIES IN THE EVOLUTION OF ANIMALS

    

 
 
     

     

  
     
 

  
   

     
 
 
   

WNT ay : 8 Ro m ity *s 4 S
<A Nye a artes a}
2 S gir ate OE
Sw : i
Lu at we

  

6B

No. 5.—Norway Lynx (Lynceus lupulinus). Light fawn, darker on back
y 8
with black spots,

 

No. 6.—Civet (Viverra civetta). Dirty white, spotted and striped black.
APPENDICES 337

 

No. 7.—Tasmanian Wolf ( Zzylacinus cynocephalus). Greyish fawn, banded brown.

 

No. 8.—Paradoxurus Derbyanus. Fawn, banded dark brown.
338 STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 9.—Delundung (Prionodon gracilis). Dirty white, piebald and spotted dark brown.
9 g si y

 

No, 10.—Nepal Linsang (Prionodon pardicolor). Dirty white, spotted brown.
APPENDICES 339

 

No. 11.—Tigrine Genet (Gezetta tigrina), Light fawn, spotted with dark brown.

 

No. 12,—Richardson’s Genet (Volana Richardsoni). Light fawn, spotted dark brown.
340. STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 13.—Galtdictes vittata. Grey, striped brown, with dots between the stripes.

 

No. 14.—Mascarene Striped Mungoose (Galidictes striata). Dark brown, with dirty
white stripes.
APPENDICES 341

 

No. 15.—South African Striped Mungoose (Crossarchus fasciatus). Grey, banded black.

 

‘No. 16,.—Paca (C@logenys paca), Dark brown, spotted with white in longitudinal rows.
342 STUDIES IN THE EVOLUTION OF ANIMALS

 

No, 17.—Common American Tapir (Tapirus terrestris). Brown, striped and spotted white.

   

LB

No. 18.—Sus Andamanensis (young). Brown stripes alternating with dirty white stripes,
343

APPENDICES

UN

“

a)

 

No. 19.—Banded Bushbuck (Cefhalolophus dorig). Deep fawn, banded black.

<Z
spotted white.

 

No. 20.—Banded Bushbuck ( 7vagelaphus scriptus), young. Fawn, striped and
344 STUDIES IN THE EVOLUTION OF ANIMALS

 

No, 22.—Broad-horned Antelope ( 7vagelaphus euryceros). Yellowish brown, striped white.
APPENDICES 345

  
   

, hy

‘nity 4

  

No. 23.—Inyala Antelope ( Zvagelaphus Angassiz). Fawn-grey, striped and spotted white.

No. 24.—Barbary Deer (Cervus darbarus), young. Deep fawn, with white spots.
346 STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 26.—Fallow Deer (Dama vulgaris). Deep fawn, spotted white.
APPENDICES 347

   

4

i

No. 27.—Hindquarters of Water Buck (Kobus ellipsiprymnus). Dark grey,
with white stripe on rump.

 

No. 27A.—Mouse Deer (Tragulus Meminna). Brown, striped and spotted white.
348 STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 28.—Lord Derby's Chevrotain (Zvagalus Stanleyanus) and Kanchil (Tvag, Javanicus).
Both very young, and having only vestiges of stripes.

ZS. Se ENA "WA Gx: ae

   

2

No, 29.—Brindled Gnu (Comochetes gorgon). Roan, striped with brown,
APPENDICES 349

 

No. 30.—Hybrid between E£guus Zebra and E. Asinus.

   
     
    
 

  

Bato,
tadlyyyon

fills
ef Yn, Viper

wn

No. 31.—Hybrid between Equus Zebra and &. Hemionus.
350 STUDIES IN THE EVOLUTION OF ANIMALS

 

No. 32.— Hybrid between Aguus Asinus and E. Hemionus.
APPENDICES 351

APPENDIX B

IN addition to the Cats mentioned in Part I., the following are also from Mr.
Elliot’s monograph of the Felide. They will serve to emphasise the fact that
stripes originate in a fusion of spots.

No. 1.—Bushy tailed red spotted Cat (Fels Euftilura). Grey, spotted
orange-brown ; chest transversely barred ; the spots are like solid distorted
rosettes ; the abdomen is pale, and the tail is ringed.

No. 2.—Bokhara Chaus (Ff. Caudata). Bluish grey, trimmed with yellow,
and spotted with black ; abdomen pale, and tail ringed.

No. 3.—Siberian Lynx (F. Cervaria). Grey, spotted with black ; abdomen
pale, and tail half ringed and half black.

No. 4.—Spanish Lynx (7. Pardina). Leopard colour, spotted with black ;
the abdomen is pale.

No. 5.—Painted Cat (F. Scriffa). Olive-grey with black distorted rosettes ;
abdomen pale, and tail ringed.

No. 6.—Little red spotted’ Cat (/ /avensis). Leopard colour or grey,
spotted and barred brown ; abdomen pale, and tail ringed or spotted.

No. 7.—Shaw’s Cat (7. Shawitana). Of a dark Leopard colour, spotted
with black ; abdomen pale, and tail ringed.

No. 8.—Bay Lynx, or American wild Cat (/. Rufa). Bluish-grey, rosetted
and spotted with black ; abdomen pale, and the short tail partly ringed.

No. 9.—European wild Cat (F. Catus). Olive-brown, trimmed with yellow
and striped black, Tiger-fashion ; tail ringed.

No. 10.—-Molina’s Guiana Cat (F. Colocolo). Whitish-grey, broadly striped
brown ; abdomen pale, and tail ringed.

No. 11.—-Pallas’s Tibetan Cat (F. MZanul). Yellowish-grey; loins, haunches,
and fore-legs barred ; hands and feet yellow ; tail ringed.

No. 12.—-Chaus (F. Chaus). Brownish-grey, almost plain, with transverse
stripes on chest and legs ; abdomen yellow, and tail ringed.

No. 13.—Caracal (F. Caracal). Rich brown, with only vestigial striping in
parts ; abdomen pale.

No. 14.—Little Malayan red Cat (F. Planicepfs). Greyish-brown, with
vestigial stripes ; spotted on the abdomen, which is pale, and barred on the
legs.
352 STUDIES IN THE EVOLUTION OF ANIMALS

No. 15.—Northern Lynx (F. Canadensis). Grey, with vestigial stripes ; its
short tail is tipped black.

No. 16.—Bornean red Cat (F. Badia). Yellowish-brown, with vestigial
stripes on chest.

No. 17.—Eyra (&. Zyra). Yellowish-brown, wholly g/azn ; abdomen pale.

No. 18.—European red Lynx (F. Lymx). Reddish-brown on back and legs ;
abdomen pale.

No. 19.—Yaguarundi (/. Yaguarund:). Like the Puma, but with stripes on
the abdomen, and spots over the eyes like those of the black-and-tan Dog.

V.B.—As there are no two Cats exactly alike, although of the same species,
two authors describing the same species from different specimens will describe
it somewhat differently. The variations in the same species and the transitions
from species to species are simply zxnumerable.

Better than any description in words will be found the pictures of Cats in
vol. i. Royal Natural History, and those of Mr. Elliot’s Fe/d@z, the mounted
animals in the Natural History Museum, and the live animals in the Zoological
Society’s Gardens.
APPENDICES 353

APPENDIX C

IN addition to the Horses given in Part II., the following short descriptions,
taken from specimens in the streets, will give some idea of the innumerable
variations of marking which are to be found among these animals. These are
some of the most striking deviations from the ordinary colorations one sees
everywhere,

No. 1.—A light bay Horse, brindled on the neck with black, like the
striping of a Cat.

No. 2.—A bay Horse on his back and neck had distinct faint stripes like
those of the Zebra.

No. 3.—An omnibus Horse, of a strawberry-roan colour, was faintly striped
on his flank, and spotted faintly on his hindquarters.

No. 4.—A dappled grey Horse with three transverse stripes on upper part
of fore-leg. a ’

No. 5.—It is no uncommon thing to see the mane of dark-grey Horses
barred white and black like that of the Zebra.

No. 6.—Bay omnibus Horse with white spots on his flank like those of the
spotted Deer.

No. 7.—A dun-coloured Horse, of the colour of a bath-sponge, with cream-
coloured dapples.

No. 8.—A flea-bitten Horse is sometimes dappled on his haunches.

No. 9.—A sponge-coloured Horse with a patch of black reticulations in front
of his tail-root and a suffused sootiness along the ridge of his neck.

No. 10.—A roan Horse with rows of about five spots on his flank inclined
in the direction of his ribs.

No. 11.—A Pony partly clipped—the unclipped part was almost white,
while the clipped part was dark-grey, dappled white.

No. 12.—A dark-grey Horse dappled all over with pale tan or dun colour.

No. 13.—A smoky-brown carriage Horse dappled with black on the hind-
quarters.

No. 14.--I have seen a roan Horse dappled all over with d/ack spots,
much like the grey, dun, or brown dappled Horse, but usually both the roan

Z
354 STUDIES IN THE EVOLUTION OF ANIMALS

and strawberry-roan Horses show only vestiges of spots, either black in the
roan, or brown in the strawberry-roan.

No. 15.-The nearest approach I have yet seen to Leopard spots in the
Horse was in a dark-brown Horse with lighter spots ; if some parts were cut
out, they might have been passed off as parts of a black Leopard.

No. 16.—A dun-coloured Horse, seven years old, in a hansom, had three or
four Zebra stripes above his wrist, and similar, but fainter ones, above his
heel.

No. 17.—A dappled grey Horse had black lines across the upper part of
fore-legs, corresponding to the transverse veins ; a little more decision in the
colour might easily turn them into Zebra stripes.

No. 18.—A white Pony had his mouth, circles round his eyes, and circlets
just above the four hoofs, all of a yellow or golden bay colour.

No. 19.—A dun-coloured omnibus Horse had a black line down his spine,
and two narrow stripes on his withers.

No. 20.—A bay Horse with white blotches and spots somewhat similar to
those of Fig. 37. ;

No. 21.—A bay or black Horse with a white mane and tail is not common,
but sometimes it is met with; dun and cream-coloured Horses with a white
mane and tail are more common.

No. 22.—A brown omnibus Horse with black spots.

No. 23.—A jet-black Horse, of the kind used in funerals, had no vestige of
spots, but its hind-feet were w/zfe. It is rare to see jet-black funeral Horses
with traces of spots on their hindquarters, but I have seen some which had
them.

No. 24.—A strawberry-roan omnibus Horse, zewly clipped, showed closely-
set rosettes like those of the Jaguar (see Fig. 56 (a)), consisting of a largish
dapple surrounded by a circle of small spots. This was the most satisfactory
example of true rosettes in the Horse. Others of a similar character are some-
times seen here and there on the Horse. Usually the rosettes are fwsed into
dapples.

No. 25.—In some dark-grey Horses the white spots are almost effaced,
and are as faint as the spots on the legs of adult Lions.

No. 26.—A bay Horse with faint black spots.

No. 27.—A white carriage Horse, spotted black on its shoulder, neck, and
fore-legs. The spots were not unlike those of the Cheetah. On the head it
had brown blotches.

No. 28.—Now and again a light bay Horse is seen with true rosettes on its
flank, almost exactly like those of a Leopard, but close together, and with all
the component spotlets distinct.

No. 29,—A black carriage Horse with a black star on a white blaze.
APPENDICES 355

No. 30.—A costermonger’s Donkey, of a light-grey colour, with faint
darker sfods on its flank, such as many Horses have. This and the following
are the only Donkeys I have seen which had any indication of having de-
scended from a spotted ancestry.

No. 31.—A grey Donkey with large dark dapples.

No. 32.--A costermonger’s brown Donkey had a white abdomen, a white
mouth, and white circles round its eyes.
356 STUDIES IN THE EVOLUTION OF ANIMALS

APPENDIX D

THE innumerable mammals which are fully or vestigially spotted or striped,
can be seen in Museums and Zoological Gardens, but it may not be generally
known that many marsupials give indication of having descended from a
spotted or striped ancestry, as the following list, taken from Gould on the
Mammals of Australia, will amply show :—

No. 1.—Antechinus maculatus has white spots on the abdomen only.

No. 2.—Dasyurus maculatus is brown, spotted with white on the body, and
also on the tail.

No. 3.—Dasyurus viverrinus (variable Dasyure), is either black or olive
colour, spotted with white on the body only. Other Dasyures are also
spotted.

No. 4.—Halmaturus Derbyanus (Derby’s Wallaby) is spotted.

No. 5.—A variety of Petrogale xanthopus (yellow-footed rock Wallaby) is
faintly spotted and faintly ring-tailed also.

No. 6.—Lagorchertes Leichhardt is spotted.

There are other Marsupials which are variously marked :—

No. 7.—Wombats, such as Phascolomys, have faint spots in various parts.

Then the following are very distinctly marked :—

No. 8.—Parameles Gunniz, banded transversely.

No. 9.— Tarsipes vostratus has three longitudinal bands.

No. 10.—AMyrmecobius fasciatus is banded like a Zebra. Thylacinus
cynocephalus (Tasmanian Wolf),—see Appendix A, No. 7,—has broad black
bands.

No. 11.—Macropus fuliginosus (Sooty Kangaroo) has vestiges of stripe
on various parts ;

No. 12.—Lagorchertes fasciatus (banded Hare-Kangaroo) is banded like a
Zebra on hindquarters, with a spinal band, and it has faint spots on other
parts.
APPENDICES 357

APPENDIX E

I CONSIDER that a ringed tail, even where no other vestige of ancestral
marking exists, is sufficient indication that the possessor of it descended from
either a rosetted, or a spotted, or a striped ancestor. This is one of those
features of which it cannot be said, when it exists a/ome as marking, that it was
brought about by natural selection to harmonise with the surroundings of the
animal, as a plain body with only the ¢az/ mottled would be too great an
absurdity in defence of harmonisation.

The following list will give some idea of the number of afferent animals
which have ringed tails :—

No. 1.—All Leopards, Tigers, the Cheetah, and all spotted and striped
Cats, have ring-tails.

No. 2.—A number of Civets and Genets, whose bodies are either spotted
or striped, have ring-tails.

No. 3.—The Delundung (Prionodon gractlis) and Hemigalea Hardwickit
are ring-tailed.

No. 4.—A Hill Fox (Vulpes montanus) is brownish-yellow with faint rings
on its tail. I saw another ring-tailed Fox in the Durham Museum.

No. §.—The red-armed Squirrel of Fernando Po (Sc¢urus rubt-brachiatus)
has a grey-brown body and a ringed tail.

No. 6.—The Grissled Squirrel (Scturus punctatus) of West Africa has a
ringed tail.

No. 7.—The Burmese Squirrel (Sczurus pygerythrus) is ring-tailed.

No. 8.—The Coati (Wasua rufa) and Bassaris astuta have ring-tails and
plain bodies.

No. 9.—A Lemur, a Marmoset, and a spotted Ichneumon, of Jamaica, have
ring-tails.

No. 1o.—The African Linsang (Pozana poensis) is spotted and also ring-
tailed.

No. 11.—The Pand (Glurus fulgens) is ring-tailed.

No. 12.—The Racoon (Procyon lotor), and the Egyptian Cat, though quite
plain, have ring-tails.
358 STUDIES IN THE EVOLUTION OF ANIMALS

No. 13.—Burchell’s Zebra and Chapman’s Zebra have their tails ringed
half-way.

Then if we turn again to Gould’s Australian Mammals we find that :—

No. 14.—Belidens scurus has vestiges of rings on its tail. Petrogale
xanthopus (yellow-footed rock Wallaby) is banded on the neck and has rings
on its tail.

No, 15.—Canzs dingo has three faint rings on its tail.

NV. B.—These lists should not be considered as giving in any way all
the animals that exist under those headings, nor are they meant for a scientific
classification of the animals contained in them.

They are only intended to show the general reader the large number of
mammals that are either spotted or striped, or are simply ring-tailed, which
feature I consider a vestige of either spotted or striped ancestry. In these lists
I have left out all domestic mammals, which are known to every one.

The probability is that even those mammals which are wholly plain at all
ages, judging from domestic animals, descended from marked ancestors also,
but from some cause they entirely lost their marks at an early period, and now
the nervous system has lost the habit of reproducing them.
INDEX

Antelopes, contrasted coloration of, 141;
markings of, 47-49.

Armadillo, why it has rosettes on abdomen,
191; hind-feet ungulate, 191; spots
on abdomen not evolved by natural
selection, 192; no excuse for rosettes
on abdomen, 193; abdominal rosettes
evidence of ancestral plate-armour, 194.

Armour-plates, of various animals, 111-115;
as blocks of Jaguar rosettes, 121; round
eyes of Ganoids, 180; early loss of,
cause of contrasted coloration, 181;
dwindling of, in certain animals, 202 ;
gradual disappearance of, 205 ; disappear-
ance due to famine of lime-salts, 206.

Asses, striped and spotted, 89, 91.

Badgers, contrasted coloration of, 138.
Begonia, spotting on leaves of, 158.
Black Buck, contrasted coloration of, 138-

141.

Blaze, of Horses and forehead star, 167-
169; on face of other mammals, 171;
possibly a vestige of ancestral forehead
and nose-horns, 172.

Blotching: of Dog, 51; of Horse, 82; of
Giraffe, 95.

Brain, development proportional to mus-
cular activity, 210.

Bull, spotting of, 95, 96.

Callesities, loss of, on legs of ruminants,
cause of distinct tufts of hair, 181-233 ;
on metatarsal region of Tragulus,
meaning of, 187, 232; on legs of
Equide, 232-240.

Cheetah, analysis of markings, 20-24.

Chlamydophorus truncatus, transition mam-
mal, 139; armour of, in transition stage,
204.

Coati, meaning of ringed tail of, 197-203.

 

 

Coloration of Mammals, Mr. Poulton’s
views, 105; Mr. Tylor’s views, 107;
Mr. Darwin’s views regarding white
marks, 108; not result of natural selec-
tion, 124; contrasted, 137-139; con-
trasted: coloration, meaning of, 139-142,
181; of Mellivora IJndica, 144; of
Putorius sarmaticus, 144; of Spotted
Deer, 145; of Skunks, 146, 147; of
Jackal and other mammals, 147; of
rosettes, 149 ; when contrasted, a vestige
of a carapace, 151 ; contrasted coloration
round mouth, eyes, and ears, meaning
of, 175; has no hard and fast fixity,
178; of cattle in Cadzow and Somer-
ford Parks, 179; siriking, in Bear of
ieee Tibet, 183; of American Bear,
184.

Crocodile, strong armour on abdomen, 193-
201.

Croft, W. B., experiments with impres-
sions on glass, 160,

Dappling, of Horse, 60-69.

Deer, spotting of, 25, 46, 1453; eye gland
of, 237, 238.

Dogs, spotted, blotched, and striped, 50-
533 Wolf ancestor of, 186.

Eimer, Professor, views on spotting and
striping, 126.

Evolution in Mammals,
stages of, 183.

four distinct

Felidae, in Elliot’s monograph, 11.

Fishes, with armour round eyes, 180.

Flower, Sir W., on origin of Horse callo-
sities, 232.

hae ae hoarding of lime-salts by,
206,
360 STUDIES IN THE EVOLUTION OF ANIMALS

Giraffe, markings of, 95, 96; New, 98;
blotching on abdomen not needed, 194.
Glass, retains impressions of coins and

print, 160.
Glyptodonts, rosettes in armour of, 109-112.

Hands and feet, white or black, genesis of,

174.

Homology, of Rhinoceros shields with
Armadillo shields, 215; of plates of X.
Sondaicus with plates of Armadillo, 218-
220; of hide-plates of Indian Rhino-
ceros with bone-plates of Crocodile and
Sturgeon, 221; of pigment reticulation
of Horse with commissures of plates of
R. Sondaicus, 222.

Horses, dappling of, 59; want of data
regarding commencement of dappling,
67; need of photographic help in estab-
lishing facts of dappling, 69; coinci-
dence of venation and reticulation, 71 ;
fern-like markings of, 72; detail study
of rosettes of, 74-77; vestiges of Zebra
marks in, 78-81; blotches in, 82; striped,
83-88; rosetted, 93; white or black
hands and feet, explanation of, 174 ; tan-
coloured circle round eye of, 177; limbs
of ancestors of, 231; abnormal hands
of, 251-2535; are they odd-toed or even-
toed, 252; characters in common with
ruminants, 267.

Hybrids, between genera of plants, 173;
between Onager and Abyssinian Ass,
170.

Interbreeding, of species and genera, 293,
294.

Jaguar, a South American Leopard, 6;
black varieties of, 6; a tree-loving
animal, 8; detail of rosettes of, 10;
modified rosettes of, 18; localised nerve-
centres of markings, 19; variants of
rosettes of, 24; marking of, not result of
natural selection, 124; coloration ele-
ments of, 162.

Leopards, identity with Panther, 7; black
cubs of, in same litter with ordinary
kinds, 7; Asiatic, differ from African, 8 ;
tree-loving animals, 8; detail of rosettes
of, 10-102; difference in markings of,

 

26 ; disposition of markings in, 27 ; spot-
ting on legs of, 40; Clouded, 35.

Lime-salts, famine of, cause of disappear-
ance of skin-armour, 207; immense
quantities required for endo-skeletons
of animals, 208 ; hoarded in lime-rocks,
206.

Lion, ancestral spotting of, 28.

Llama, callosities on hind-legs of, 236.

Lydehker, kichard, views on spotting and
striping of mammals, 126.

Mammals, striped or spotted, 3; tail-rings
of, 3-12; earliest record of striped, 4;
markings of, supposed to be result of
natural selection, 5; unsymmetry of
markings in, 5; invisibility of, owing to
markings, 6; markings of, dependent on
nerve-centres, 26, 27; review of mark-
ings of, 54, 553 skeleton of, developed
independently of coloration of skin,
126; contrasted coloration of certain,
137-139; white or black hands and feet
in, explanation of, 1743; contrasted
coloration round mouth, eyes, and ears
of, 175; four distinct stages in evolution
of, 183; endo-skeleton of, required
immense quantities of lime-salts, 208.

Marbled Cat, descent from rosetted ances-
tors, 30, 35.

Afarkings, of Jaguar, 9, 13, 18, 24; of
Leopard, 9-15, 18, 27; of Cheetah, 20-
23; of Spotted Deer, 25, 46, 145; of
Lion, 29; of Puma, 29; of Serval, 30;
of Marbled Cat, 31; of Ocelots, 32,
33; of Tigers, 36-41, 44; of Lynx,
40; of smaller Cats, 42, 43; of Zebras,
83, 84; on operculum of Pearly Nautilus,
120; on Jaguar, impressions of ancestral
carapace, 120; meaning of, on fore-legs
of Leopards, 124; of Jaguar not result of
natural selection, 124; of fishes, 155;
round mouth, eyes, and ears of certain
mammals, 175; on hind-legs of Serval,
30, 186; on abdomen of Giraffe and
Horse not needed, 194; of Leopards
evidence of ancestral scutes, 202; order
in which they altered in Mammals, 211.

Monstrostties, in various animals, 276-279,
2875; rejection of, by Dr. Wallace as
modifiers of species, 280; sub-division
of, 282; probable cause of, 282-286;
Geoffroy St. Hilaire’s propositions on,
INDEX 361

289; possible explanation of, ‘264;
digital, 295; in Guinea-pig, 302; in
Myosotis, 304; wide range of monstrous
species, 317; Hornbills as monstrous
birds, 318; monstrous human hands and
feet, 321 ; a help towards comprehend-
ing the doctrine of evolution, 323.

Natural selection, maintained but not ori-
ginated skin-rosetting, 196, 197.

Nervous system, habits and memories of,
alter very slowly, 227.

Ocelot, analysis of markings, 32-34.

Odontoglossum crispum, markings of, 24.

Orchids, persistent abnormality in sexual
organs of, 255.

Order in which markings of mammals have
altered, 211.

Ostracion, unarmoured lips of, 180.

Pangolins, wnarmoured parts of, 1413
scales of, agglutinated hairs, 159; char-
acteristics of, 181.

Peaches and other fruit, colouring of, 139.

Pichiciago, ramp shield of, 140; transition
stage of armour of, 204.

Pig, abnormal hand of, 247.

Plates, armour, of various animals, I1I-
115; fusion of, in Glyptodon, 117; in
Leathery Turtle, 118 ; restored in ances-
tral Jaguar, 122; on abdomen of Great
Armadillo, 123; transverse on fore-legs
of Hairy Armadillo, 124; of Dolphins,
133; originally both dorsal and ventral,
1513; in fishes, 155-157; homology of,
with pigment rosettes, 161 ; early loss of,
round mouth, eyes, and ears, 175;
influenced by nervous system, 121;
disappeared gradually, 204-205; dis-
appearance of, due to famine of lime-
salts, 206, 207,

Polydactylism, cases of, 294-298 ; in Ichthy-
osaurs, 299.

Propithecus, contrasted coloration of, 138.

Puma, ancestral spotting of, 28.

Quagga, coloration of, 87-88.

Rabbit, meaning of white under-surface of
tail, 143.

Racoon, ringed tail of, vestige of ancestral
body-spotting, 28, 203.

 

Reason, why huge extinct animals have
had pigmy descendants, 209; of rachi-
tic egg-skin, 210.

Relationship, of markings of Horse,
Giraffe, and Zebu, to plating of Arma-
dillo and Rhinoceros, 215, 224.

Rosettes, of Jaguar, 9, 14, 18, 24, 75; of
Leopard, 4, 9, 15-18, 27; of Ocelots,
32, 333; of Horse, 75, 76, 933 of Zebu,
95; of Jaguar, meaning of, 109 ; varia-
tions of, in Jaguar and Leopard, 102;
bone-rosettes of Glyptodonts, 109, 112;
of Polacanthus, 112 ; of Leathery Turtle,
118; of Crocodile and Sturgeon, 118 ;.
of extinct fishes, 119; of-Jaguar not
result of natural selection, 124; rosettes
and spots have deeper meaning than
general colour, 159; why on abdomen
of Armadillo, 191; on abdomen of
Leopard, why more altered than on back,
201.

Ruminants, endo-skeletons of, absorbed
immense quantities of lime-salts, 208 ;
contrasts of hair-tufts on legs of, evidence
of ancestral callosities, 233, 234; char-
acters of, in common with Horses, 267.

Scutes, dermal, disappeared gradually, 204,
205.

Selous, #. C., on markings of Antelopes,.
47; hiding in tall grass, 238; on
Antelopes living in waterless regions, 48.

Serval, origin of markings of, 30 ; meaning
of black marks from heel to toes, 30;
melanoid varieties of, 11.

Serranus gigas, spotting of, 156; other
species of, with vestiges of plate-armour,

157.

Sheep, fleece of, what it tells us, 1443
Cyprian, white mouth of, 177.

Skeleton, of mammals developed independ-
ently of skin-coloration, 126.

Skunks, coloration of, 146, 147.

Spinal fine, of certain mammals, possible
meaning of, 140.

Spotted Deer, markings of, 25 ; what they
tellus, 144.

Spotting, of Cheetah, 20, 23; of Deer,
25, 46, 145; of Lion, 28; of Puma, 28 ;
of Serval, 30; of Marbled Cat, 30; of
Dog, 50; of Horse, 77; of Bull, 95;
over eyes of black-and-tan Dog, meaning
of, 176.

2A
362

Striping, of Tigers, 36, 41, 443; of small
Cats, 42, 43; of Dog, 52; of Horse, 77,
80; of Zebras, 83, 88; of Antelopes, 47.

Supernumerary digits, cases of, 294-298.

Survivals, of wholly armoured, of partly
armoured, and of unarmoured stages of
animals, 204, 205.

Symmetry, want of,
animals, 283.

on both sides of

Tails, ringed, 35, 43; of Coati, 183;
evidence, when ringed, of ancestral ro-
setted or striped body, 197 ; of Racoon,
203.

Teratogeny, experiments in, 290.

Tiger, analysis of markingsin, 35, 39, 403
extraordinary ocelli on skin of, 41, 44.
Types, new, inroad of, in geological times,
307-311; speculations as to possible

causes of, 311.

 

 

 

STUDIES IN THE EVOLUTION OF ANIMALS

Veins, reticular on Horse flank, equiva-
lents of commissures in armour of 2.
Sondaicus, 225.

Vertebrates, comparison of limbs of, 249,
257, 261, 264.

Vestages, of ancestral features, 178.

Viverride, markings of, 53.

Werner, Franz, researches on spotting of
animals, 73.
Wolf, ancestor of Dog, 186.

Zebra, variations in striping of, 83, 88;
coloration of feet of Chapman’s, 179;
stripes on abdomen not needed, 194;
Grevy’s, wholly without callosities, 85,

234.
Zebu, rosetting of, 95, 97.
Zeuglodonts, armour-plating of, 133.

Printed by T. and A. ConsTaBLe, Printers to Her Majesty
at the Edinburgh University Press.
Tn SH