Studies in the evolution of animals

Front matter

‘ 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 vou can to reach the heart and soul of the great multitude of your fellow-men.’

'ike Man of Letters as a Man of Business, by W. D. Howells, Scribner's Magazine , October 1893.

STUDIES IN THE

Part i. — Spotted and Striped Mammals (Horses excepted), . . i

„ II. — Dappled and Striped Horses, and some other Mammals, . 57

,, ill. — Meaning- of the Jaguar and Leopard Rosettes, and of the

markings of other Mammals, .... 99

„ iv. — Further evidence in support of the theory that existing Mam¬ mals descended from carapaced ancestors, . . 135

„ v. — Researches and discussions to connect, more surely, Armour¬ plating with Skin-picturing, . . . 153

,, vi. — Probable meaning of some interesting features in Horses and

other animals, ...... 165

,, vii. — Is Natural Selection the sole factor in the Coloration of

,, viii. — Probable cause of the loss of the Calcareous Armour in

,, ix. — -Relationship between the Armadillo, the Rhinoceros, the

Horse, the Giraffe, and the Zebu, . . .213

VI

PAGE

Part X, — Explanation of the Callosities on the Legs of Equine xMnmals

and others, ......

„ XI. — The One Big Digit of the Horse, ....

„ XU. — Monstrosities as probable factors in the creation of species, . General Conclusions, .......

Appendices, .......

Preface

Of what value would the objective facts alone have been, even if they were collected by millions, zuithout a colligating theory which puts soul 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 fads, 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 its Outcomes , I 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

— 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 value 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 xi 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,1 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 that 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.

Xll 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 detail , 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 xm

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 plan, 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 archaeological 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. B0NAV1A.

‘ 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. 1.

‘ It 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,’ Nature , 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 Muller. 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 Precis de Teratologic, 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 meme consequence que la multi-

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 “ Bioplastology,” 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.

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 Lydekker1 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 end 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 Romanes2 compared to the nine circles of Dante’s Inferno !

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.

- Examination of Weismannism, p. 118.

XX 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 the 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.

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 antennae of the Lobster are homologous with podites , 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 its revenge!

The mischief of all this is that the mass of mankind, even in the most civilised countries, both men and women, are wholly ignorant 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 Geikie1 says: ‘When I attended school, the text¬ books used by my teachers were about as repellent as they could be.’

And at p. 1 2 : ‘ 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. i ,

XXII 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 if 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 is 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

XXlll 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 always 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 manoeuvred 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

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 not 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 ist June 1S94,1 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 1 Lecture printed in Nature of 7th June 1894, p. 133.

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 no doubt.

Mr. Herbert Spencer1 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. Hutchinson2 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 land mammals alone may be true or untrue. 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 1S93, P* 9°9-

2 Creatures of Other Days, p. 131.

XXVI

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 land 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 land 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 without getting out of the water.

Are we so sure, in spite of ‘ agreement among zoologists,’ that the Whales are degenerated land 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 without 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 deeraded to