The Variation of Animals and Plants under Domestication Volume 1 by Charles Darwin

The Variation of Animals and Plants Under Domestication was the first attempt by Charles Darwin to explain the phenomina of heredity and pangenesis under a unified theory. Published in 1868, it emerged into a scientific world already grappling with the theories of Georges Louis Leclerc, Comte de Buffon, and Charles Bonnet.

PREFACE TO THE SECOND EDITION.

During the seven years which have elapsed since the publication in 1868 of the first edition of this Work, I have continued to attend to the same subjects, as far as lay in my power; and I have thus accumulated a large body of additional facts, chiefly through the kindness of many correspondents. Of these facts I have been able here to use only those which seemed to me the more important. I have omitted some statements, and corrected some errors, the discovery of which I owe to my reviewers. Many additional references have been given. The eleventh chapter, and that on Pangenesis, are those which have been most altered, parts having been re- modelled; but I will give a list of the more important alterations for the sake of those who may possess the first edition of this book.

LIST OF ILLUSTRATIONS.

FIGURE.

1. DUN DEVONSHIRE PONY, WITH SHOULDER, SPINAL, AND LEG STRIPES.
2. HEAD OF JAPAN OR MASKED PIG.
3. HEAD OF WILD BOAR, AND OF “GOLDEN DAYS,” A PIG OF THE YORKSHIRE LARGE BREED.
4. OLD IRISH PIG WITH JAW-APPENDAGES.
5. HALF-LOP RABBIT.
6. SKULL OF WILD RABBIT.
7. SKULL OF LARGE LOP-EARED RABBIT.
8. PART OF ZYGOMATIC ARCH, SHOWING THE PROJECTING END OF THE MALAR BONE OF THE AUDITORY MEATUS, OF RABBITS.
9. POSTERIOR END OF SKULL, SHOWING THE INTER-PARIETAL BONE, OF RABBITS.
10. OCCIPITAL FORAMEN OF RABBITS.
11. SKULL OF HALF-LOP RABBIT.
12. ATLAS VERTEBRAE OF RABBITS.
13. THIRD CERVICAL VERTEBRAE OF RABBITS.
14. DORSAL VERTEBRAE, FROM SIXTH TO TENTH INCLUSIVE, OF RABBITS.
15. TERMINAL BONE OF STERNUM OF RABBITS.
16. ACROMION OF SCAPULA OF RABBITS.
17. THE ROCK-PIGEON, OR COLUMBA LIVIA.
18. ENGLISH POUTER.
19. ENGLISH CARRIER.
20. ENGLISH BARB.
21. ENGLISH FANTAIL.
22. AFRICAN OWL.
23. SHORT-FACED ENGLISH TUMBLER.
24. SKULLS OF PIGEONS, VIEWED LATERALLY.
25. LOWER JAWS OF PIGEONS, SEEN FROM ABOVE.
26. SKULL OF RUNT, SEEN FROM ABOVE.
27. LATERAL VIEW OF JAWS OF PIGEONS.
28. SCAPULAE OF PIGEONS.
29. FURCULA OF PIGEONS.
30. SPANISH FOWL.
31. HAMBURGH FOWL.
32. POLISH FOWL.
33. OCCIPITAL FORAMEN OF THE SKULLS OF FOWLS.
34. SKULLS OF FOWLS, VIEWED FROM ABOVE, A LITTLE OBLIQUELY.
35. LONGITUDINAL SECTIONS OF SKULLS OF FOWLS, VIEWED LATERALLY.
36. SKULL OF HORNED FOWL, VIEWED FROM ABOVE, A LITTLE OBLIQUELY.
37. SIXTH CERVICAL VERTEBRAE OF FOWLS, VIEWED LATERALLY.
38. EXTREMITY OF THE FURCULA OF FOWLS, VIEWED LATERALLY.
39. SKULLS OF DUCKS, VIEWED LATERALLY, REDUCED TO TWO-THIRDS OF THE NATURAL
SIZE.
40. CERVICAL VERTEBRAE OF DUCKS, OF NATURAL SIZE.
41. PODS OF THE COMMON PEA.
42. PEACH AND ALMOND STONES, OF NATURAL SIZE, VIEWED EDGEWAYS.
43. PLUM STONES, OF NATURAL SIZE, VIEWED LATERALLY.

TABLE 1: PRINCIPAL ADDITIONS AND CORRECTIONS IN THIS (SECOND) EDITION.

First Edition, Volume I., Page 34.
Second Edition Volume I., Page 35.
Dr. Burt Wilder’s observations on the brains of different breeds of the Dog.

First Edition, Volume I., Page 38.
Second Edition Volume I., Page 40.
Degeneracy of Dogs imported into Guinea.

First Edition, Volume I., Page 51.
Second Edition Volume I., Page 54.
Difference in the number of the lumbar vertebrae in the races or species of the Horse.

First Edition, Volume I., Page 102.
Second Edition Volume I., Page 106. Hairy appendages to the throats of Goats.

First Edition, Volume I., Page 162.
Second Edition Volume I., Page 170. Sexual differences in colour in the domestic Pigeon.

First Edition, Volume I., Page 217.
Second Edition Volume I., Page 228. Movements like those of the Tumbler-pigeon, caused by injury to the brain.

First Edition, Volume I., Page 290.
Second Edition Volume I., Page 306. Additional facts with respect to the Black-shouldered Peacock.

First Edition, Volume I., Page 296.
Second Edition Volume I., Page 312. Ancient selection of Gold-fish in China.

First Edition, Volume I., Page 314.
Second Edition Volume I., Page 332. Major Hallett’s ‘Pedigree Wheat.’

First Edition, Volume I., Page 326.
Second Edition Volume I., Page 345. The common radish descended from Raphanus raphanistrum.

First Edition, Volume I., Page 374.
Second Edition Volume I., Page 398. Several additional cases of bud-variation given.

First Edition, Volume I., Page 396.
Second Edition Volume I., Page 420. An abstract of all the cases recently published of graft-hybrids in the potato, together with a general summary on graft-hybridisation.

First Edition, Volume I., Page 399.
Second Edition Volume I., Page 429. An erroneous statement with respect to the pollen of the date-palm affecting the fruit of the Chamaerops omitted.

First Edition, Volume I., Page 400.
Second Edition Volume I., Page 430. New cases of the direct action of pollen on the mother-plant.

First Edition, Volume I., Page 404.
Second Edition Volume I., Page 435. Additional and remarkable instances of the action of the male parent on the future progeny of the female.

First Edition, Volume II., Page 14.
Second Edition Volume I., Page 459. An erroneous statement corrected, with respect to the regrowth of supernumerary digits after amputation.

First Edition, Volume II., Page 23.
Second Edition Volume I., Page 467. Additional facts with respect to the inherited effects of circumcision.

First Edition, Volume II., Page 23.
Second Edition Volume I., Page 467. Dr. Brown-Sequard on the inherited effects of operations on the Guinea-pig.

First Edition, Volume II., Page 24.
Second Edition Volume I., Page 469. Other cases of inherited mutilations.

First Edition, Volume II., Page 43.
Second Edition Volume II., Page 17. An additional case of reversion due to a cross.

First Edition, Volume II., Page 72.
Second Edition Volume II., Page 48. Inheritance as limited by sex.

First Edition, Volume II., Page 105.
Second Edition Volume II., Page 83. Two varieties of maize which cannot be crossed.

First Edition, Volume II., Page 120.
Second Edition Volume II., Page 99. Some additional facts on the advantages of cross-breeding in animals.

First Edition, Volume II., Page 123.
Second Edition Volume II., Page 103. Discussion on the effects of close interbreeding in the case of man.

First Edition, Volume II., Page 135 to 141. Second Edition Volume II., Page 117 to 122. Additional cases of plants sterile with pollen from the same plant.

First Edition, Volume II., Page 149.
Second Edition Volume II., Page 131. Mr. Sclater on the infertility of animals under confinement.

First Edition, Volume II., Page 152.
Second Edition Volume II., Page 134. The Aperea a distinct species from the Guinea-pig.

First Edition, Volume II., Page 230.
Second Edition Volume II., Page 215. Professor Jager on hawks killing light-coloured pigeons.

First Edition, Volume II., Page 273.
Second Edition Volume II., Page 262. Professor Weismann on the effects of isolation in the development of species.

First Edition, Volume II., Page 281.
Second Edition Volume II., Page 271. The direct action of the conditions of life in causing variation.

First Edition, Volume II., Page 317.
Second Edition Volume II., Page 309. Mr. Romanes on rudimentary parts.

First Edition, Volume II., Page 324 to 328. Second Edition Volume II., Page 316 to 327. Some additional cases of correlated variability.

First Edition, Volume II., Page 339.
Second Edition Volume II., Page 333. On Geoffroy St.-Hilaire’s law of “soi pour soi.”

First Edition, Volume II., Page 357 to 404. Second Edition Volume II., Page 349 to 399. The chapter on Pangenesis has been largely altered and re-modelled; but the essential principles remain the same.

THE VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION.

INTRODUCTION.

The object of this work is not to describe all the many races of animals which have been domesticated by man, and of the plants which have been cultivated by him; even if I possessed the requisite knowledge, so gigantic an undertaking would be here superfluous. It is my intention to give under the head of each species only such facts as I have been able to collect or observe, showing the amount and nature of the changes which animals and plants have undergone whilst under man’s dominion, or which bear on the general principles of variation. In one case alone, namely in that of the domestic pigeon, I will describe fully all the chief races, their history, the amount and nature of their differences, and the probable steps by which they have been formed. I have selected this case, because, as we shall hereafter see, the materials are better than in any other; and one case fully described will in fact illustrate all others. But I shall also describe domesticated rabbits, fowls, and ducks, with considerable fulness.

The subjects discussed in this volume are so connected that it is not a little difficult to decide how they can be best arranged. I have determined in the first part to give, under the heads of the various animals and plants, a large body of facts, some of which may at first appear but little related to our subject, and to devote the latter part to general discussions. Whenever I have found it necessary to give numerous details, in support of any proposition or conclusion, small type has been used. (Here shown with indentation.) The reader will, I think, find this plan a convenience, for, if he does not doubt the conclusion or care about the details, he can easily pass them over; yet I may be permitted to say that some of the discussions thus printed deserve attention, at least from the professed naturalist.

It may be useful to those who have read nothing about Natural Selection, if I here give a brief sketch of the whole subject and of its bearing on the origin of species. (Introduction/1. To any one who has attentively read my ‘Origin of Species’ this Introduction will be superfluous. As I stated in that work that I should soon publish the facts on which the conclusions given in it were founded, I here beg permission to remark that the great delay in publishing this first work has been caused by continued ill- health.) This is the more desirable, as it is impossible in the present work to avoid many allusions to questions which will be fully discussed in future volumes.

From a remote period, in all parts of the world, man has subjected many animals and plants to domestication or culture. Man has no power of altering the absolute conditions of life; he cannot change the climate of any country; he adds no new element to the soil; but he can remove an animal or plant from one climate or soil to another, and give it food on which it did not subsist in its natural state. It is an error to speak of man “tampering with nature” and causing variability. If a man drops a piece of iron into sulphuric acid, it cannot be said strictly that he makes the sulphate of iron, he only allows their elective affinities to come into play. If organic beings had not possessed an inherent tendency to vary, man could have done nothing. (Introduction/2. M. Pouchet has recently (‘Plurality of Races’ English Translation 1864 page 83 etc.) insisted that variation under domestication throws no light on the natural modification of species. I cannot perceive the force of his arguments, or, to speak more accurately, of his assertions to this effect.) He unintentionally exposes his animals and plants to various conditions of life, and variability supervenes, which he cannot even prevent or check. Consider the simple case of a plant which has been cultivated during a long time in its native country, and which consequently has not been subjected to any change of climate. It has been protected to a certain extent from the competing roots of plants of other kinds; it has generally been grown in manured soil; but probably not richer than that of many an alluvial flat; and lastly, it has been exposed to changes in its conditions, being grown sometimes in one district and sometimes in another, in different soils. Under such circumstances, scarcely a plant can be named, though cultivated in the rudest manner, which has not given birth to several varieties. It can hardly be maintained that during the many changes which this earth has undergone, and during the natural migrations of plants from one land or island to another, tenanted by different species, that such plants will not often have been subjected to changes in their conditions analogous to those which almost inevitably cause cultivated plants to vary. No doubt man selects varying individuals, sows their seeds, and again selects their varying offspring. But the initial variation on which man works, and without which he can do nothing, is caused by slight changes in the conditions of life, which must often have occurred under nature. Man, therefore, may be said to have been trying an experiment on a gigantic scale; and it is an experiment which nature during the long lapse of time has incessantly tried. Hence it follows that the principles of domestication are important for us. The main result is that organic beings thus treated have varied largely, and the variations have been inherited. This has apparently been one chief cause of the belief long held by some few naturalists that species in a state of nature undergo change.

I shall in this volume treat, as fully as my materials permit, the whole subject of variation under domestication. We may thus hope to obtain some light, little though it be, on the causes of variability,–on the laws which govern it, such as the direct action of climate and food, the effects of use and disuse, and of correlation of growth,–and on the amount of change to which domesticated organisms are liable. We shall learn something of the laws of inheritance, of the effects of crossing different breeds, and on that sterility which often supervenes when organic beings are removed from their natural conditions of life, and likewise when they are too closely interbred. During this investigation we shall see that the principle of Selection is highly important. Although man does not cause variability and cannot even prevent it, he can select, preserve, and accumulate the variations given to him by the hand of nature almost in any way which he chooses; and thus he can certainly produce a great result. Selection may be followed either methodically and intentionally, or unconsciously and unintentionally. Man may select and preserve each successive variation, with the distinct intention of improving and altering a breed, in accordance with a preconceived idea; and by thus adding up variations, often so slight as to be imperceptible by an uneducated eye, he has effected wonderful changes and improvements. It can, also, be clearly shown that man, without any intention or thought of improving the breed, by preserving in each successive generation the individuals which he prizes most, and by destroying the worthless individuals, slowly, though surely, induces great changes. As the will of man thus comes into play, we can understand how it is that domesticated breeds show adaptation to his wants and pleasures. We can further understand how it is that domestic races of animals and cultivated races of plants often exhibit an abnormal character, as compared with natural species; for they have been modified not for their own benefit, but for that of man.

In another work I shall discuss, if time and health permit, the variability of organic beings in a state of nature; namely, the individual differences presented by animals and plants, and those slightly greater and generally inherited differences which are ranked by naturalists as varieties or geographical races. We shall see how difficult, or rather how impossible it often is, to distinguish between races and sub-species, as the less well- marked forms have sometimes been denominated; and again between sub-species and true species. I shall further attempt to show that it is the common and widely ranging, or, as they may be called, the dominant species, which most frequently vary; and that it is the large and flourishing genera which include the greatest number of varying species. Varieties, as we shall see, may justly be called incipient species.

But it may be urged, granting that organic beings in a state of nature present some varieties,–that their organisation is in some slight degree plastic; granting that many animals and plants have varied greatly under domestication, and that man by his power of selection has gone on accumulating such variations until he has made strongly marked and firmly inherited races; granting all this, how, it may be asked, have species arisen in a state of nature? The differences between natural varieties are slight; whereas the differences are considerable between the species of the same genus, and great between the species of distinct genera. How do these lesser differences become augmented into the greater difference? How do varieties, or as I have called them incipient species, become converted into true and well-defined species? How has each new species been adapted to the surrounding physical conditions, and to the other forms of life on which it in any way depends? We see on every side of us innumerable adaptations and contrivances, which have justly excited the highest admiration of every observer. There is, for instance, a fly (Cecidomyia (Introduction/3. Leon Dufour in ‘Annales des Science. Nat.’ (3rd series, Zoolog.) tome 5 page 6.)) which deposits its eggs within the stamens of a Scrophularia, and secretes a poison which produces a gall, on which the larva feeds; but there is another insect (Misocampus) which deposits its eggs within the body of the larva within the gall, and is thus nourished by its living prey; so that here a hymenopterous insect depends on a dipterous insect, and this depends on its power of producing a monstrous growth in a particular organ of a particular plant. So it is, in a more or less plainly marked manner, in thousands and tens of thousands of cases, with the lowest as well as with the highest productions of nature.

This problem of the conversion of varieties into species,–that is, the augmentation of the slight differences characteristic of varieties into the greater differences characteristic of species and genera, including the admirable adaptations of each being to its complex organic and inorganic conditions of life,–has been briefly treated in my ‘Origin of Species.’ It was there shown that all organic beings, without exception, tend to increase at so high a ratio, that no district, no station, not even the whole surface of the land or the whole ocean, would hold the progeny of a single pair after a certain number of generations. The inevitable result is an ever-recurrent Struggle for Existence. It has truly been said that all nature is at war; the strongest ultimately prevail, the weakest fail; and we well know that myriads of forms have disappeared from the face of the earth. If then organic beings in a state of nature vary even in a slight degree, owing to changes in the surrounding conditions, of which we have abundant geological evidence, or from any other cause; if, in the long course of ages, inheritable variations ever arise in any way advantageous to any being under its excessively complex and changing relations of life; and it would be a strange fact if beneficial variations did never arise, seeing how many have arisen which man has taken advantage of for his own profit or pleasure; if then these contingencies ever occur, and I do not see how the probability of their occurrence can be doubted, then the severe and often-recurrent struggle for existence will determine that those variations, however slight, which are favourable shall be preserved or selected, and those which are unfavourable shall be destroyed.

This preservation, during the battle for life, of varieties which possess any advantage in structure, constitution, or instinct, I have called Natural Selection; and Mr. Herbert Spencer has well expressed the same idea by the Survival of the Fittest. The term “natural selection” is in some respects a bad one, as it seems to imply conscious choice; but this will be disregarded after a little familiarity. No one objects to chemists speaking of “elective affinity;” and certainly an acid has no more choice in combining with a base, than the conditions of life have in determining whether or not a new form be selected or preserved. The term is so far a good one as it brings into connection the production of domestic races by man’s power of selection, and the natural preservation of varieties and species in a state of nature. For brevity sake I sometimes speak of natural selection as an intelligent power;–in the same way as astronomers speak of the attraction of gravity as ruling the movements of the planets, or as agriculturists speak of man making domestic races by his power of selection. In the one case, as in the other, selection does nothing without variability, and this depends in some manner on the action of the surrounding circumstances on the organism. I have, also, often personified the word Nature; for I have found it difficult to avoid this ambiguity; but I mean by nature only the aggregate action and product of many natural laws,–and by laws only the ascertained sequence of events.

It has been shown from many facts that the largest amount of life can be supported on each area, by great diversification or divergence in the structure and constitution of its inhabitants. We have, also, seen that the continued production of new forms through natural selection, which implies that each new variety has some advantage over others, inevitably leads to the extermination of the older and less improved forms. These latter are almost necessarily intermediate in structure, as well as in descent, between the last-produced forms and their original parent-species. Now, if we suppose a species to produce two or more varieties, and these in the course of time to produce other varieties, the principal of good being derived from diversification of structure will generally lead to the preservation of the most divergent varieties; thus the lesser differences characteristic of varieties come to be augmented into the greater differences characteristic of species, and, by the extermination of the older intermediate forms, new species end by being distinctly defined objects. Thus, also, we shall see how it is that organic beings can be classed by what is called a natural method in distinct groups–species under genera, and genera under families.

As all the inhabitants of each country may be said, owing to their high rate of reproduction, to be striving to increase in numbers; as each form comes into competition with many other forms in the struggle for life,–for destroy any one and its place will be seized by others; as every part of the organisation occasionally varies in some slight degree, and as natural selection acts exclusively by the preservation of variations which are advantageous under the excessively complex conditions to which each being is exposed, no limit exists to the number, singularity, and perfection of the contrivances and co-adaptations which may thus be produced. An animal or a plant may thus slowly become related in its structure and habits in the most intricate manner to many other animals and plants, and to the physical conditions of its home. Variations in the organisation will in some cases be aided by habit, or by the use and disuse of parts, and they will be governed by the direct action of the surrounding physical conditions and by correlation of growth.

On the principles here briefly sketched out, there is no innate or necessary tendency in each being to its own advancement in the scale of organisation. We are almost compelled to look at the specialisation or differentiation of parts or organs for different functions as the best or even sole standard of advancement; for by such division of labour each function of body and mind is better performed. And as natural selection acts exclusively through the preservation of profitable modifications of structure, and as the conditions of life in each area generally become more and more complex from the increasing number of different forms which inhabit it and from most of these forms acquiring a more and more perfect structure, we may confidently believe, that, on the whole, organisation advances. Nevertheless a very simple form fitted for very simple conditions of life might remain for indefinite ages unaltered or unimproved; for what would it profit an infusorial animalcule, for instance, or an intestinal worm, to become highly organised? Members of a high group might even become, and this apparently has often occurred, fitted for simpler conditions of life; and in this case natural selection would tend to simplify or degrade the organisation, for complicated mechanism for simple actions would be useless or even disadvantageous.

The arguments opposed to the theory of Natural Selection, have been discussed in my ‘Origin of Species,’ as far as the size of that work permitted, under the following heads: the difficulty in understanding how very simple organs have been converted by small and graduated steps into highly perfect and complex organs; the marvellous facts of Instinct; the whole question of Hybridity; and, lastly, the absence in our known geological formations of innumerable links connecting all allied species. Although some of these difficulties are of great weight, we shall see that many of them are explicable on the theory of natural selection, and are otherwise inexplicable.

In scientific investigations it is permitted to invent any hypothesis, and if it explains various large and independent classes of facts it rises to the rank of a well-grounded theory. The undulations of the ether and even its existence are hypothetical, yet every one now admits the undulatory theory of light. The principle of natural selection may be looked at as a mere hypothesis, but rendered in some degree probable by what we positively know of the variability of organic beings in a state of nature,–by what we positively know of the struggle for existence, and the consequent almost inevitable preservation of favourable variations,–and from the analogical formation of domestic races. Now this hypothesis may be tested,–and this seems to me the only fair and legitimate manner of considering the whole question,–by trying whether it explains several large and independent classes of facts; such as the geological succession of organic beings, their distribution in past and present times, and their mutual affinities and homologies. If the principle of natural selection does explain these and other large bodies of facts, it ought to be received. On the ordinary view of each species having been independently created, we gain no scientific explanation of any one of these facts. We can only say that it has so pleased the Creator to command that the past and present inhabitants of the world should appear in a certain order and in certain areas; that He has impressed on them the most extraordinary resemblances, and has classed them in groups subordinate to groups. But by such statements we gain no new knowledge; we do not connect together facts and laws; we explain nothing.

It was the consideration of such large groups of facts as these which first led me to take up the present subject. When I visited during the voyage of H.M.S. “Beagle,” the Galapagos Archipelago, situated in the Pacific Ocean about 500 miles from South America, I found myself surrounded by peculiar species of birds, reptiles, and plants, existing nowhere else in the world. Yet they nearly all bore an American stamp. In the song of the mocking- thrush, in the harsh cry of the carrion-hawk, in the great candlestick-like opuntias, I clearly perceived the neighbourhood of America, though the islands were separated by so many miles of ocean from the mainland, and differed much in their geological constitution and climate. Still more surprising was the fact that most of the inhabitants of each separate island in this small archipelago were specifically different, though most closely related to each other. The archipelago, with its innumerable craters and bare streams of lava, appeared to be of recent origin; and thus I fancied myself brought near to the very act of creation. I often asked myself how these many peculiar animals and plants had been produced: the simplest answer seemed to be that the inhabitants of the several islands had descended from each other, undergoing modification in the course of their descent; and that all the inhabitants of the archipelago were descended from those of the nearest land, namely America, whence colonists would naturally have been derived. But it long remained to me an inexplicable problem how the necessary degree of modification could have been effected, and it would have thus remained for ever, had I not studied domestic productions, and thus acquired a just idea of the power of Selection. As soon as I had fully realised this idea, I saw, on reading Malthus on Population, that Natural Selection was the inevitable result of the rapid increase of all organic beings; for I was prepared to appreciate the struggle for existence by having long studied the habits of animals.

Before visiting the Galapagos I had collected many animals whilst travelling from north to south on both sides of America, and everywhere, under conditions of life as different as it is possible to conceive, American forms were met with–species replacing species of the same peculiar genera. Thus it was when the Cordilleras were ascended, or the thick tropical forests penetrated, or the fresh waters of America searched. Subsequently I visited other countries, which in all their conditions of life were incomparably more like parts of South America, than the different parts of that continent are to each other; yet in these countries, as in Australia or Southern Africa, the traveller cannot fail to be struck with the entire difference of their productions. Again the reflection was forced on me that community of descent from the early inhabitants of South America would alone explain the wide prevalence of American types throughout that immense area.

To exhume with one’s own hands the bones of extinct and gigantic quadrupeds brings the whole question of the succession of species vividly before one’s mind; and I found in South America great pieces of tesselated armour exactly like, but on a magnificent scale, that covering the pigmy armadillo; I had found great teeth like those of the living sloth, and bones like those of the cavy. An analogous succession of allied forms had been previously observed in Australia. Here then we see the prevalence, as if by descent, in time as in space, of the same types in the same areas; and in neither the case does the similarity of the conditions by any means seem sufficient to account for the similarity of the forms of life. It is notorious that the fossil remains of closely consecutive formations are closely allied in structure, and we can at once understand the fact if they are closely allied by descent. The succession of the many distinct species of the same genus throughout the long series of geological formations seems to have been unbroken or continuous. New species come in gradually one by one. Ancient and extinct forms of life are often intermediate in character, like the words of a dead language with respect to its several offshoots or living tongues. All these facts seemed to me to point to descent with modification as the means of production of new species.

The innumerable past and present inhabitants of the world are connected together by the most singular and complex affinities, and can be classed in groups under groups, in the same manner as varieties can be classed under species and sub-varieties under varieties, but with much higher grades of difference. These complex affinities and the rules for classification, receive a rational explanation on the theory of descent, combined with the principle of natural selection, which entails divergence of character and the extinction of intermediate forms. How inexplicable is the similar pattern of the hand of a man, the foot of a dog, the wing of a bat, the flipper of a seal, on the doctrine of independent acts of creation! how simply explained on the principle of the natural selection of successive slight variations in the diverging descendants from a single progenitor! So it is with certain parts or organs in the same individual animal or plant, for instance, the jaws and legs of a crab, or the petals, stamens, and pistils of a flower. During the many changes to which in the course of time organic beings have been subjected, certain organs or parts have occasionally become at first of little use and ultimately superfluous; and the retention of such parts in a rudimentary and useless condition is intelligible on the theory of descent. It can be shown that modifications of structure are generally inherited by the offspring at the same age at which each successive variation appeared in the parents; it can further be shown that variations do not commonly supervene at a very early period of embryonic growth, and on these two principles we can understand that most wonderful fact in the whole circuit of natural history, namely, the close similarity of the embryos within the same great class–for instance, those of mammals, birds, reptiles, and fish.

It is the consideration and explanation of such facts as these which has convinced me that the theory of descent with modification by means of natural selection is in the main true. These facts have as yet received no explanation on the theory of independent Creation; they cannot be grouped together under one point of view, but each has to be considered as an ultimate fact. As the first origin of life on this earth, as well as the continued life of each individual, is at present quite beyond the scope of science, I do not wish to lay much stress on the greater simplicity of the view of a few forms or of only one form having been originally created, instead of innumerable miraculous creations having been necessary at innumerable periods; though this more simple view accords well with Maupertuis’s philosophical axiom of “least action.”

In considering how far the theory of natural selection may be extended, –that is, in determining from how many progenitors the inhabitants of the world have descended,–we may conclude that at least all the members of the same class have descended from a single ancestor. A number of organic beings are included in the same class, because they present, independently of their habits of life, the same fundamental type of structure, and because they graduate into each other. Moreover, members of the same class can in most cases be shown to be closely alike at an early embryonic age. These facts can be explained on the belief of their descent from a common form; therefore it may be safely admitted that all the members of the same class are descended from one progenitor. But as the members of quite distinct classes have something in common in structure and much in common in constitution, analogy would lead us one step further, and to infer as probable that all living creatures are descended from a single prototype.

I hope that the reader will pause before coming to any final and hostile conclusion on the theory of natural selection. The reader may consult my ‘Origin of Species’ for a general sketch of the whole subject; but in that work he has to take many statements on trust. In considering the theory of natural selection, he will assuredly meet with weighty difficulties, but these difficulties relate chiefly to subjects–such as the degree of perfection of the geological record, the means of distribution, the possibility of transitions in organs, etc.–on which we are confessedly ignorant; nor do we know how ignorant we are. If we are much more ignorant than is generally supposed, most of these difficulties wholly disappear. Let the reader reflect on the difficulty of looking at whole classes of facts from a new point of view. Let him observe how slowly, but surely, the noble views of Lyell on the gradual changes now in progress on the earth’s surface have been accepted as sufficient to account for all that we see in its past history. The present action of natural selection may seem more or less probable; but I believe in the truth of the theory, because it collects, under one point of view, and gives a rational explanation of, many apparently independent classes of facts. (Introduction/4. In treating the several subjects included in the present and my other works I have continually been led to ask for information from many zoologists, botanists, geologists, breeders of animals, and horticulturists, and I have invariably received from them the most generous assistance. Without such aid I could have effected little. I have repeatedly applied for information and specimens to foreigners, and to British merchants and officers of the Government residing in distant lands, and, with the rarest exceptions, I have received prompt, open-handed, and valuable assistance. I cannot express too strongly my obligations to the many persons who have assisted me, and who, I am convinced, would be equally willing to assist others in any scientific investigation.)

CHAPTER 1.I. — DOMESTIC DOGS AND CATS.

The first and chief point of interest in this chapter is, whether the numerous domesticated varieties of the dog have descended from a single wild species, or from several. Some authors believe that all have descended from the wolf, or from the jackal, or from an unknown and extinct species. Others again believe, and this of late has been the favourite tenet, that they have descended from several species, extinct and recent, more or less commingled together. We shall probably never be able to ascertain their origin with certainty. Palaeontology (1/1. Owen ‘British Fossil Mammals’ pages 123 to 133. Pictet ‘Traite de Pal.’ 1853 tome 1 page 202. De Blainville in his ‘Osteographie, Canidae’ page 142 has largely discussed the whole subject, and concludes that the extinct parent of all domesticated dogs came nearest to the wolf in organisation, and to the jackal in habits. See also Boyd Dawkins, ‘Cave Hunting’ 1874 page 131 etc. and his other publications. Jeitteles has discussed in great detail the character of the breeds of pre-historic dogs: ‘Die vorgeschichtlichen Alterthumer der Stadt Olmutz’ II. Theil, 1872 page 44 to end.) does not throw much light on the question, owing, on the one hand, to the close similarity of the skulls of extinct as well as living wolves and jackals, and owing, on the other hand, to the great dissimilarity of the skulls of the several breeds of the domestic dogs. It seems, however, that remains have been found in the later tertiary deposits more like those of a large dog than of a wolf, which favours the belief of De Blainville that our dogs are the descendants of a single extinct species. On the other hand, some authors go so far as to assert that every chief domestic breed must have had its wild prototype. This latter view is extremely improbable: it allows nothing for variation; it passes over the almost monstrous character of some of the breeds; and it almost necessarily assumes that a large number of species have become extinct since man domesticated the dog; whereas we plainly see that wild members of the dog-family are extirpated by human agency with much difficulty; even so recently as 1710 the wolf existed in so small an island as Ireland.

The reasons which have led various authors to infer that our dogs have descended from more than one wild species are as follows. (1/2. Pallas, I believe, originated this doctrine in ‘Act. Acad. St. Petersburgh’ 1780 Part 2. Ehrenberg has advocated it, as may be seen in De Blainville’s ‘Osteographie’ page 79. It has been carried to an extreme extent by Col. Hamilton Smith in the ‘Naturalist Library’ volumes 9 and 10. Mr. W.C. Martin adopts it in his excellent ‘History of the Dog’ 1845; as does Dr. Morton, as well as Nott and Gliddon, in the United States. Prof. Low, in his ‘Domesticated Animals’ 1845 page 666, comes to this same conclusion. No one has argued on this side with more clearness and force than the late James Wilson, of Edinburgh, in various papers read before the Highland Agricultural and Wernerian Societies. Isidore Geoffroy Saint-Hilaire (‘Hist. Nat. Gen.’ 1860 tome 3 page 107), though he believes that most dogs have descended from the jackal, yet inclines to the belief that some are descended from the wolf. Prof. Gervais (‘Hist. Nat. Mamm.’ 1855 tome 2 page 69, referring to the view that all the domestic races are the modified descendants of a single species, after a long discussion, says, “Cette opinion est, suivant nous du moins, la moins probable.”) Firstly, the great difference between the several breeds; but this will appear of comparatively little weight, after we shall have seen how great are the differences between the several races of various domesticated animals which certainly have descended from a single parent-form. Secondly, the more important fact, that, at the most anciently known historical periods, several breeds of the dog existed, very unlike each other, and closely resembling or identical with breeds still alive.

We will briefly run back through the historical records. The materials are remarkably deficient between the fourteenth century and the Roman classical period. (1/3. Berjeau ‘The Varieties of the Dog; in old Sculptures and Pictures’ 1863. ‘Der Hund’ von Dr. F.L. Walther, Giessen 1817 s. 48: this author seems carefully to have studied all classical works on the subject. See also Volz ‘Beitrage zur Kulturgeschichte’ Leipzig 1852 s. 115, ‘Youatt on the Dog’ 1845 page 6. A very full history is given by De Blainville in his ‘Osteographie, Canidae.’) At this latter period various breeds, namely hounds, house-dogs, lapdogs, etc, existed; but, as Dr. Walther has remarked, it is impossible to recognise the greater number with any certainty. Youatt, however, gives a drawing of a beautiful sculpture of two greyhound puppies from the Villa of Antoninus. On an Assyrian monument, about 640 B.C.,an enormous mastiff (1/4. I have seen drawings of this dog from the tomb of the son of Esar Haddon, and clay models in the British Museum. Nott and Gliddon, in their ‘Types of Mankind’ 1854 page 393, give a copy of these drawings. This dog has been called a Thibetan mastiff, but Mr. H.A. Oldfield, who is familiar with the so-called Thibet mastiff, and has examined the drawings in the British Museum, informs me that he considers them different.) is figured; and according to Sir H. Rawlinson (as I was informed at the British Museum), similar dogs are still imported into this same country. I have looked through the magnificent works of Lepsius and Rosellini, and on the Egyptian monuments from the fourth to the twelfth dynasties (i.e. from about 3400 B.C. to 2100 B.C.) several varieties of the dog are represented; most of them are allied to greyhounds; at the later of these periods a dog resembling a hound is figured, with drooping ears, but with a longer back and more pointed head than in our hounds. There is, also, a turnspit, with short and crooked legs, closely resembling the existing variety; but this kind of monstrosity is so common with various animals, as with the ancon sheep, and even, according to Rengger, with jaguars in Paraguay, that it would be rash to look at the monumental animal as the parent of all our turnspits: Colonel Sykes (1/5. ‘Proc. Zoolog. Soc.’ July 12, 1831.) also has described an Indian pariah dog as presenting the same monstrous character. The most ancient dog represented on the Egyptian monuments is one of the most singular; it resembles a greyhound, but has long pointed ears and a short curled tail: a closely allied variety still exists in Northern Africa; for Mr. E. Vernon Harcourt (1/6. ‘Sporting in Algeria’ page 51.) states that the Arab boar-hound is “an eccentric hieroglyphic animal, such as Cheops once hunted with, somewhat resembling the rough Scotch deer-hound; their tails are curled tight round on their backs, and their ears stick out at right angles.” With this most ancient variety a pariah-like dog coexisted.

We thus see that, at a period between four and five thousand years ago, various breeds, viz. pariah dogs, greyhounds, common hounds, mastiffs, house-dogs, lapdogs, and turnspits, existed, more or less closely resembling our present breeds. But there is not sufficient evidence that any of these ancient dogs belonged to the same identical sub-varieties with our present dogs. (1/7. Berjeau gives facsimiles of the Egyptian drawings. Mr. C.L. Martin in his ‘History of the Dog’ 1845 copies several figures from the Egyptian monuments, and speaks with much confidence with respect to their identity with still living dogs. Messrs. Nott and Gliddon (‘Types of Mankind’ 1854 page 388) give still more numerous figures. Mr. Gliddon asserts that a curl-tailed greyhound, like that represented on the most ancient monuments, is common in Borneo; but the Rajah, Sir J. Brooke, informs me that no such dog exists there.) As long as man was believed to have existed on this earth only about 6000 years, this fact of the great diversity of the breeds at so early a period was an argument of much weight that they had proceeded from several wild sources, for there would not have been sufficient time for their divergence and modification. But now that we know, from the discovery of flint tools embedded with the remains of extinct animals in districts which have since undergone great geographical changes, that man has existed for an incomparably longer period, and bearing in mind that the most barbarous nations possess domestic dogs, the argument from insufficient time falls away greatly in value.

Long before the period of any historical record the dog was domesticated in Europe. In the Danish Middens of the Neolithic or Newer Stone period, bones of a canine animal are embedded, and Steenstrup ingeniously argues that these belonged to a domestic dog; for a very large proportion of the bones of birds preserved in the refuse consists of long bones, which it was found on trial dogs cannot devour. (1/8. These, and the following facts on the Danish remains, are taken from M. Morlot’s most interesting memoir in ‘Soc. Vaudoise des Sc. Nat.’ tome 6 1860 pages 281, 299, 320.) This ancient dog was succeeded in Denmark during the Bronze period by a larger kind, presenting certain differences, and this again during the Iron period, by a still larger kind. In Switzerland, we hear from Prof. Rutimeyer (1/9. ‘Die Fauna der Pfahlbauten’ 1861 s. 117, 162.), that during the Neolithic period a domesticated dog of middle size existed, which in its skull was about equally remote from the wolf and jackal, and partook of the characters of our hounds and setters or spaniels (Jagdhund und Wachtelhund). Rutimeyer insists strongly on the constancy of form during a very long period of time of this the most ancient known dog. During the Bronze period a larger dog appeared, and this closely resembled in its jaw a dog of the same age in Denmark. Remains of two notably distinct varieties of the dog were found by Schmerling in a cave (1/10. De Blainville ‘Osteographie, Canidae.’); but their age cannot be positively determined.

The existence of a single race, remarkably constant in form during the whole Neolithic period, is an interesting fact in contrast with what we see of the changes which the races underwent during the period of the successive Egyptian monuments, and in contrast with our existing dogs. The character of this animal during the Neolithic period, as given by Rutimeyer, supports De Blainville’s view that our varieties have descended from an unknown and extinct form. But we should not forget that we know nothing with respect to the antiquity of man in the warmer parts of the world. The succession of the different kinds of dogs in Switzerland and Denmark is thought to be due to the immigration of conquering tribes bringing with them their dogs; and this view accords with the belief that different wild canine animals were domesticated in different regions. Independently of the immigration of new races of man, we know from the wide-spread presence of bronze, composed of an alloy of tin, how much commerce there must have been throughout Europe at an extremely remote period, and dogs would then probably have been bartered. At the present time, amongst the savages of the interior of Guiana, the Taruma Indians are considered the best trainers of dogs, and possess a large breed which they barter at a high price with other tribes. (1/11. Sir R. Schomburgk has given me information on this head. See also ‘Journal of R. Geographical Soc.’ volume 13 1843 page 65.)

The main argument in favour of the several breeds of the dog being the descendants of distinct wild stocks, is their resemblance in various countries to distinct species still existing there. It must, however, be admitted that the comparison between the wild and domesticated animal has been made but in few cases with sufficient exactness. Before entering on details, it will be well to show that there is no a priori difficulty in the belief that several canine species have been domesticated. Members of the dog family inhabit nearly the whole world; and several species agree pretty closely in habits and structure with our several domesticated dogs. Mr. Galton has shown (1/12. ‘Domestication of Animals’ Ethnological Soc. December 22, 1863.) how fond savages are of keeping and taming animals of all kinds. Social animals are the most easily subjugated by man, and several species of Canidae hunt in packs. It deserves notice, as bearing on other animals as well as on the dog, that at an extremely ancient period, when man first entered any country, the animals living there would have felt no instinctive or inherited fear of him, and would consequently have been tamed far more easily than at present. For instance, when the Falkland Islands were first visited by man, the large wolf-like dog (Canis antarcticus) fearlessly came to meet Byron’s sailors, who, mistaking this ignorant curiosity for ferocity, ran into the water to avoid them: even recently a man, by holding a piece of meat in one hand and a knife in the other, could sometimes stick them at night. On a island in the Sea of Aral, when first discovered by Butakoff, the saigak antelopes, which are “generally very timid and watchful, did not fly from us, but on the contrary looked at us with a sort of curiosity.” So, again, on the shores of the Mauritius, the manatee was not at first in the least afraid of man, and thus it has been in several quarters of the world with seals and the morse. I have elsewhere shown (1/13. ‘Journal of Researches’ etc. 1845 page 393. With respect to Canis antarcticus, see page 193. For the case of the antelope, see ‘Journal Royal Geographical Soc.’ volume 23 page 94.) how slowly the native birds of several islands have acquired and inherited a salutary dread of man: at the Galapagos Archipelago I pushed with the muzzle of my gun hawks from a branch, and held out a pitcher of water for other birds to alight on and drink. Quadrupeds and birds which have seldom been disturbed by man, dread him no more than do our English birds, the cows, or horses grazing in the fields.

It is a more important consideration that several canine species evince (as will be shown in a future chapter) no strong repugnance or inability to breed under confinement; and the incapacity to breed under confinement is one of the commonest bars to domestication. Lastly, savages set the highest value, as we shall see in the chapter on Selection, on dogs: even half- tamed animals are highly useful to them: the Indians of North America cross their half-wild dogs with wolves, and thus render them even wilder than before, but bolder: the savages of Guiana catch and partially tame and use the whelps of two wild species of Canis, as do the savages of Australia those of the wild Dingo. Mr. Philip King informs me that he once trained a wild Dingo puppy to drive cattle, and found it very useful. From these several considerations we see that there is no difficulty in believing that man might have domesticated various canine species in different countries. It would indeed have been a strange fact if one species alone had been domesticated throughout the world.

We will now enter into details. The accurate and sagacious Richardson says, “The resemblance between the Northern American wolves (Canis lupus, var. occidentalis) and the domestic dogs of the Indians is so great that the size and strength of the wolf seems to be the only difference. I have more than once mistaken a band of wolves for the dogs of a party of Indians; and the howl of the animals of both species is prolonged so exactly in the same key that even the practised ear of the Indian fails at times to discriminate them.’ He adds that the more northern Esquimaux dogs are not only extremely like the grey wolves of the Arctic circle in form and colour, but also nearly equal them in size. Dr. Kane has often seen in his teams of sledge-dogs the oblique eye (a character on which some naturalists lay great stress), the drooping tail, and scared look of the wolf. In disposition the Esquimaux dogs differ little from wolves, and, according to Dr. Hayes, they are capable of no attachment to man, and are so savage that when hungry they will attack even their masters. According to Kane they readily become feral. Their affinity is so close with wolves that they frequently cross with them, and the Indians take the whelps of wolves “to improve the breed of their dogs.” The half-bred wolves sometimes (Lamare- Picquot) cannot be tamed, “though this case is rare;” but they do not become thoroughly well broken in till the second or third generation. These facts show that there can be but little, if any, sterility between the Esquimaux dog and the wolf, for otherwise they would not be used to improve the breed. As Dr. Hayes says of these dogs, “reclaimed wolves they doubtless are.” (1/14. The authorities for the foregoing statements are as follow:–Richardson in ‘Fauna Boreali-Americana’ 1829 pages 64, 75; Dr. Kane ‘Arctic Explorations’ 1856 volume 1 pages 398, 455; Dr. Hayes ‘Arctic Boat Journey’ 1860 page 167. Franklin’s ‘Narrative’ volume 1 page 269, gives the case of three whelps of a black wolf being carried away by the Indians. Parry, Richardson, and others, give accounts of wolves and dogs naturally crossing in the eastern parts of North America. Seeman in his ‘Voyage of H.M.S. “Herald”‘ 1853 volume 2 page 26, says the wolf is often caught by the Esquimaux for the purpose of crossing with their dogs, and thus adding to their size and strength. M. Lamare-Picquot in ‘Bull. de la Soc. d’Acclimat.’ tome 7 1860 page 148, gives a good account of the half- bred Esquimaux dogs.)

North America is inhabited by a second kind of wolf, the prairie-wolf (Canis latrans), which is now looked at by all naturalists as specifically distinct from the common wolf; and is, according to Mr. J.K. Lord, in some respects intermediate in habits between a wolf and a fox. Sir J. Richardson, after describing the Hare Indian dog, which differs in many respects from the Esquimaux dog, says, “It bears the same relation to the prairie-wolf that the Esquimaux dog does to the great grey wolf.” He could, in fact, detect no marked difference between them; and Messrs. Nott and Gliddon give additional details showing their close resemblance. The dogs derived from the above two aboriginal sources cross together and with the wild wolves, at least with the C. occidentalis, and with European dogs. In Florida, according to Bartram, the black wolf-dog of the Indians differs in nothing from the wolves of that country except in barking. (1/15. ‘Fauna Boreali-Americana’ 1829 pages 73, 78, 80. Nott and Gliddon, ‘Types of Mankind’ page 383. The naturalist and traveller Bartram is quoted by Hamilton Smith in ‘Naturalist Lib.’ volume 10 page 156. A Mexican domestic dog seems also to resemble a wild dog of the same country; but this may be the prairie-wolf. Another capable judge, Mr. J.K. Lord (‘The Naturalist in Vancouver Island’ 1866 volume 2 page 218), says that the Indian dog of the Spokans, near the Rocky Mountains, “is beyond all question nothing more than a tamed Cayote or prairie-wolf,” or Canis latrans.)

Turning to the southern parts of the new world, Columbus found two kinds of dogs in the West Indies; and Fernandez (1/16. I quote this from Mr. R. Hill’s excellent account of the Alco or domestic dog of Mexico, in Gosse’s ‘Naturalist’s Sojourn in Jamaica’ 1851 page 329.) describes three in Mexico: some of these native dogs were dumb–that is, did not bark. In Guiana it has been known since the time of Buffon that the natives cross their dogs with an aboriginal species, apparently the Canis cancrivorus. Sir R. Schomburgk, who has so carefully explored these regions, writes to me, “I have been repeatedly told by the Arawaak Indians, who reside near the coast, that they cross their dogs with a wild species to improve the breed, and individual dogs have been shown to me which certainly resembled the C. cancrivorus much more than the common breed. It is but seldom that the Indians keep the C. cancrivorus for domestic purposes, nor is the Ai, another species of wild dog, and which I consider to be identical with the Dusicyon silvestris of H. Smith, now much used by the Arecunas for the purpose of hunting. The dogs of the Taruma Indians are quite distinct, and resemble Buffon’s St. Domingo greyhound.” It thus appears that the natives of Guiana have partially domesticated two aboriginal species, and still cross their dogs with them; these two species belong to a quite different type from the North American and European wolves. A careful observer, Rengger (1/17. ‘Naturgeschichte der Saugethiere von Paraguay’ 1830 s. 151.), gives reasons for believing that a hairless dog was domesticated when America was first visited by Europeans: some of these dogs in Paraguay are still dumb, and Tschudi (1/18. Quoted in Humboldt ‘Aspects of Nature’ (English translation) volume 1 page 108.) states that they suffer from cold in the Cordillera. This naked dog is, however quite distinct from that found preserved in the ancient Peruvian burial-places, and described by Tschudi, under the name of Canis ingae, as withstanding cold well and as barking. It is not known whether these two distinct kinds of dog are the descendants of native species, and it might be argued that when man first migrated into America he brought with him from the Asiatic continent dogs which had not learned to bark; but this view does not seem probable, as the natives along the line of their march from the north reclaimed, as we have seen, at least two N. American species of Canidae.

Turning to the Old World, some European dogs closely resemble the wolf; thus the shepherd dog of the plains of Hungary is white or reddish-brown, has a sharp nose, short, erect ears, shaggy coat, and bushy tail, and so much resembles a wolf that Mr. Paget, who gives this description, says he has known a Hungarian mistake a wolf for one of his own dogs. Jeitteles, also, remarks on the close similarity of the Hungarian dog and wolf. Shepherd dogs in Italy must anciently have closely resembled wolves, for Columella (vii. 12) advises that white dogs be kept, adding, “pastor album probat, ne pro lupo canem feriat.” Several accounts have been given of dogs and wolves crossing naturally; and Pliny asserts that the Gauls tied their female dogs in the woods that they might cross with wolves. (1/19. Paget ‘Travels in Hungary and Transylvania’ volume 1 page 501. Jeitteles ‘Fauna Hungariae Superioris’ 1862 s. 13. See Pliny ‘History of the World’ (English translation) 8th book ch. 40 about the Gauls crossing their dogs. See also Aristotle ‘Hist. Animal.’ Lib. 8 c. 28. For good evidence about wolves and dogs naturally crossing near the Pyrenees, see M. Mauduyt ‘Du Loup et de ses Races’ Poitiers, 1851; also Pallas in ‘Acta Acad. St. Petersburgh’ 1780 part 2 page 94.) The European wolf differs slightly from that of North America, and has been ranked by many naturalists as a distinct species. The common wolf of India is also by some esteemed as a third species, and here again we find a marked resemblance between the pariah dogs of certain districts of India and the Indian wolf. (1/20. I give this on excellent authority, namely Mr. Blyth (under the signature of Zoophilus) in the ‘Indian Sporting Review’ October 1856 page 134. Mr. Blyth states that he was struck with the resemblance between a brush-tailed race of pariah-dogs, north-west of Cawnpore, and the Indian wolf. He gives corroborative evidence with respect to the dogs of the valley of the Nerbudda.)

With respect to Jackals, Isidore Geoffroy Saint-Hilaire (1/21. For numerous and interesting details on the resemblance of dogs and jackals see Isid. Geoffroy St.-Hilaire ‘Hist. Nat. Gen.’ 1860 tome 3 page 101. See also ‘Hist. Nat. des Mammiferes’ par Prof. Gervais, 1855 tome 2 page 60.) says that not one constant difference can be pointed out between their structure and that of the smaller races of dogs. They agree closely in habits: jackals, when tamed and called by their master, wag their tails, lick his hands, crouch, and throw themselves on their backs; they smell at the tails of other dogs, and void their urine sideways; they roll on carrion or on animals which they have killed; and, lastly, when in high spirits, they run round in circles or in a figure of eight, with their tails between their legs. (1/22. Also Guldenstadt ‘Nov. Comment. Acad. Petrop.’ tome 20 pro anno 1775 page 449. Also Salvin in ‘Land and Water’ October 1869.) A number of excellent naturalists, from the time of Guldenstadt to that of Ehrenberg, Hemprich, and Cretzschmar, have expressed themselves in the strongest terms with respect to the resemblance of the half-domestic dogs of Asia and Egypt to jackals. M. Nordmann, for instance, says, “Les chiens d’Awhasie ressemblent etonnamment a des chacals.” Ehrenberg (1/23. Quoted by De Blainville in his ‘Osteographie, Canidae’ pages 79, 98.) asserts that the domestic dogs of Lower Egypt, and certain mummied dogs, have for their wild type a species of wolf (C. lupaster) of the country; whereas the domestic dogs of Nubia and certain other mummied dogs have the closest relation to a wild species of the same country, viz. C. sabbar, which is only a form of the common jackal. Pallas asserts that jackals and dogs sometimes naturally cross in the East; and a case is on record in Algeria. (1/24. See Pallas in ‘Act. Acad. St. Petersburgh’ 1780 part 2 page 91. For Algeria, see Isid. Geoffroy St.-Hilaire ‘Hist. Nat. Gen.’ tome 3 page 177. In both countries it is the male jackal which pairs with female domestic dogs.) The greater number of naturalists divide the jackals of Asia and Africa into several species, but some few rank them all as one.

I may add that the domestic dogs on the coast of Guinea are fox-like animals, and are dumb. (1/25. John Barbut ‘Description of the Coast of Guinea in 1746.’) On the east coast of Africa, between latitude 4 deg and 6 deg south, and about ten days’ journey in the interior, a semi-domestic dog, as the Rev. S. Erhardt informs me, is kept, which the natives assert is derived from a similar wild animal. Lichtenstein (1/26. ‘Travels in South Africa’ volume 2 page 272.) says that the dogs of the Bosjemans present a striking resemblance even in colour (excepting the black stripe down the back) with the C. mesomelas of South Africa. Mr. E. Layard informs me that he has seen a Caffre dog which closely resembled an Esquimaux dog. In Australia the Dingo is both domesticated and wild; though this animal may have been introduced aboriginally by man, yet it must be considered as almost an endemic form, for its remains have been found in a similar state of preservation and associated with extinct mammals, so that its introduction must have been ancient. (1/27. Selwyn, Geology of Victoria; ‘Journal of Geolog. Soc.’ volume 14 1858 page 536 and volume 16 1860 page 148; and Prof. M’Coy in ‘Annals and Mag. of Nat. Hist.’ (3rd series) volume 9 1862 page 147. The Dingo differs from the dogs of the central Polynesian islands. Dieffenbach remarks (‘Travels’ volume 2 page 45) that the native New Zealand dog also differs from the Dingo.)

From this resemblance of the half-domesticated dogs in several countries to the wild species still living there,–from the facility with which they can often be crossed together,–from even half-tamed animals being so much valued by savages,–and from the other circumstances previously remarked on which favour their domestication, it is highly probable that the domestic dogs of the world are descended from two well-defined species of wolf (viz. C. lupus and C. latrans), and from two or three other doubtful species (namely, the European, Indian, and North African wolves); from at least one or two South American canine species; from several races or species of jackal; and perhaps from one or more extinct species. Although it is possible or even probable that domesticated dogs, introduced into any country and bred there for many generations, might acquire some of the characters proper to the aboriginal Canidae of the country, we can hardly thus account for introduced dogs having given rise to two breeds in the same country, resembling two of its aboriginal species, as in the above- given cases of Guiana and of North America. (1/28. These latter remarks afford, I think, a sufficient answer to some criticisms by Mr. Wallace, on the multiple origin of dogs, given in Lyell’s ‘Principles of Geology’ 1872 volume 2 page 295.)

It cannot be objected to the view of several canine species having been anciently domesticated, that these animals are tamed with difficulty: facts have been already given on this head, but I may add that the young of the Canis primaevus of India were tamed by Mr. Hodgson (1/29. ‘Proceedings Zoological Soc.’ 1833 page 112. See also on the taming of the common wolf, L. Lloyd ‘Scandinavian Adventures’ 1854 volume 1 page 460. With respect to the jackal, see Prof. Gervais ‘Hist. Nat. Mamm.’ tome 2 page 61. With respect to the aguara of Paraguay see Rengger’s work.), and became as sensible of caresses, and manifested as much intelligence, as any sporting dog of the same age. There is not much difference, as we have already shown and shall further see, in habits between the domestic dogs of the North American Indians and the wolves of that country, or between the Eastern pariah dogs and jackals, or between the dogs which have run wild in various countries and the several natural species of the family. The habit of barking, however, which is almost universal with domesticated dogs, forms an exception, as it does not characterise a single natural species of the family, though I am assured that the Canis latrans of North America utters a noise which closely approaches a bark. But this habit is soon lost by dogs when they become feral and is soon reacquired when they are again domesticated. The case of the wild dogs on the island of Juan Fernandez having become dumb has often been quoted, and there is reason to believe (130. Roulin, in ‘Mem. present. par divers Savans’ tome 6 page 341.) that the dumbness ensued in the course of thirty-three years; on the other hand, dogs taken from this island by Ulloa slowly reacquired the habit of barking. The Mackenzie-river dogs, of the Canis latrans type, when brought to England, never learned to bark properly; but one born in the Zoological Gardens (1/31. Martin ‘History of the Dog’ page 14.) “made his voice sound as loudly as any other dog of the same age and size.” According to Professor Nillson (1/32. Quoted by L. Lloyd in ‘Field Sports of North of Europe’ volume 1 page 387.), a wolf-whelp reared by a bitch barks. I. Geoffroy Saint-Hilaire exhibited a jackal which barked with the same tone as any common dog. (1/33. Quatrefages ‘Soc. d’Acclimat.’ May 11, 1863 page 7.) An interesting account has been given by Mr. G. Clarke (1/34. ‘Annals and Mag of Nat. Hist.’ volume 15 1845 page 140.) of some dogs run wild on Juan de Nova, in the Indian Ocean; “they had entirely lost the faculty of barking; they had no inclination for the company of other dogs, nor did they acquire their voice” during a captivity of several months. On the island they “congregate in vast packs, and catch sea-birds with as much address as foxes could display.” The feral dogs of La Plata have not become dumb; they are of large size, hunt singly or in packs, and burrow holes for their young. (1/35. Azara ‘Voyages dans l’Amer. Merid.’ tome 1 page 381; his account is fully confirmed by Rengger. Quatrefages gives an account of a bitch brought from Jerusalem to France which burrowed a hole and littered in it. See ‘Discours, Exposition des Races Canines’ 1865 page 3.) In these habits the feral dogs of La Plata resemble wolves and jackals; both of which hunt either singly or in packs, and burrow holes. (1/36. With respect to wolves burrowing holes see Richardson ‘Fauna Boreali-Americana’ page 64; and Bechstein ‘Naturgeschichte Deutschlands’ b. 1 s. 617.) These feral dogs have not become uniform in colour on Juan Fernandez, Juan de Nova, or La Plata. (1/37. See Poeppig ‘Reise in Chile’ b. 1 s. 290; Mr. G. Clarke, as above; and Rengger, s. 155.) In Cuba the feral dogs are described by Poeppig as nearly all mouse-coloured, with short ears and light-blue eyes. In St. Domingo, Col. Ham. Smith says (1/38. Dogs, ‘Nat. Library’ volume 10 page 121; an endemic South American dog seems also to have become feral in this island. See Gosse ‘Jamaica’ page 340.) that the feral dogs are very large, like greyhounds, of a uniform pale blue-ash, with small ears, and large light-brown eyes. Even the wild Dingo, though so anciently naturalised in Australia, “varies considerably in colour,” as I am informed by Mr. P.P. King: a half-bred Dingo reared in England (1/39. Low ‘Domesticated Animals’ page 650.) showed signs of wishing to burrow.

From the several foregoing facts we see that reversion in the feral state gives no indication of the colour or size of the aboriginal parent-species. One fact, however, with respect to the colouring of domestic dogs, I at one time hoped might have thrown some light on their origin; and it is worth giving, as showing how colouring follows laws, even in so anciently and thoroughly domesticated an animal as the dog. Black dogs with tan-coloured feet, whatever breed they may belong to, almost invariably have a tan- coloured spot on the upper and inner corners of each eye, and their lips are generally thus coloured. I have seen only two exceptions to this rule, namely, in a spaniel and terrier. Dogs of a light-brown colour often have a lighter, yellowish-brown spot over the eyes; sometimes the spot is white, and in a mongrel terrier the spot was black. Mr. Waring kindly examined for me a stud of fifteen greyhounds in Suffolk: eleven of them were black, or black and white, or brindled, and these had no eye-spots; but three were red and one slaty-blue, and these four had dark-coloured spots over their eyes. Although the spots thus sometimes differ in colour, they strongly tend to be tan-coloured; this is proved by my having seen four spaniels, a setter, two Yorkshire shepherd dogs, a large mongrel, and some fox-hounds, coloured black and white, with not a trace of tan-colour, excepting the spots over the eyes, and sometimes a little on the feet. These latter cases, and many others, show plainly that the colour of the feet and the eye-spots are in some way correlated. I have noticed, in various breeds, every gradation, from the whole face being tan-coloured, to a complete ring round the eyes, to a minute spot over the inner and upper corners. The spots occur in various sub-breeds of terriers and spaniels; in setters; in hounds of various kinds, including the turnspit-like German badger-hound; in shepherd dogs; in a mongrel, of which neither parent had the spots; in one pure bulldog, though the spots were in this case almost white; and in greyhounds,–but true black-and-tan greyhounds are excessively rare; nevertheless I have been assured by Mr. Warwick, that one ran at the Caledonian Champion meeting of April 1860, and was “marked precisely like a black-and-tan terrier.” This dog, or another exactly the same colour, ran at the Scottish National Club on the 21st of March, 1865; and I hear from Mr. C.M. Browne, that “there was no reason either on the sire or dam side for the appearance of this unusual colour.” Mr. Swinhoe at my request looked at the dogs in China, at Amoy, and he soon noticed a brown dog with yellow spots over the eyes. Colonel H. Smith (1/40. ‘The Naturalist Library’ Dogs, volume 10 pages 4, 19.) figures the magnificent black mastiff of Thibet with a tan-coloured stripe over the eyes, feet, and chaps; and what is more singular, he figures the Alco, or native domestic dog of Mexico, as black and white, with narrow tan-coloured rings round the eyes; at the Exhibition of dogs in London, May 1863, a so-called forest dog from North-West Mexico was shown, which had pale tan-coloured spots over the eyes. The occurrence of these tan-coloured spots in dogs of such extremely different breeds, living in various parts of the world, makes the fact highly remarkable.

We shall hereafter see, especially in the chapter on Pigeons, that coloured marks are strongly inherited, and that they often aid us in discovering the primitive forms of our domestic races. Hence, if any wild canine species had distinctly exhibited the tan-coloured spots over the eyes, it might have been argued that this was the parent-form of nearly all our domestic races. But after looking at many coloured plates, and through the whole collection of skins in the British Museum, I can find no species thus marked. It is no doubt possible that some extinct species was thus coloured. On the other hand, in looking at the various species, there seems to be a tolerably plain correlation between tan-coloured legs and face; and less frequently between black legs and a black face; and this general rule of colouring explains to a certain extent the above-given cases of correlation between the eye-spots and the colour of the feet. Moreover, some jackals and foxes have a trace of a white ring round their eyes, as in C. mesomelas, C. aureus, and (judging from Colonel H. Smith’s drawing) in C. alopex, and C. thaleb. Other species have a trace of a black line over the corners of the eyes, as in C. variegatus, cinereo-variegatus, and fulvus, and the wild Dingo. Hence I am inclined to conclude that a tendency for tan-coloured spots to appear over the eyes in the various breeds of dogs, is analogous to the case observed by Desmarest, namely, that when any white appears on a dog the tip of the tail is always white, “de maniere a rappeler la tache terminale de meme couleur, qui caracterise la plupart des Canides sauvages.” (1/41. Quoted by Prof. Gervais ‘Hist. Nat. Mamm.’ tome 2 page 66.) This rule, however, as I am assured by Mr. Jesse, does not invariably hold good.

It has been objected that our domestic dogs cannot be descended from wolves or jackals, because their periods of gestation are different. The supposed difference rests on statements made by Buffon, Gilibert, Bechstein, and others; but these are now known to be erroneous; and the period is found to agree in the wolf, jackal, and dog, as closely as could be expected, for it is often in some degree variable. (1/42. J. Hunter shows that the long period of seventy-three days given by Buffon is easily explained by the bitch having received the dog many times during a period of sixteen days (‘Phil. Transact.’ 1787 page 353). Hunter found that the gestation of a mongrel from wolf and dog (‘Phil. Transact.’ 1789 page 160) apparently was sixty-three days, for she received the dog more than once. The period of a mongrel dog and jackal was fifty-nine days. Fred. Cuvier found the period of gestation of the wolf to be (‘Dict. Class. d’Hist. Nat.’ tome 4 page 8) two months and a few days, which agrees with the dog. Isid G. St.-Hilaire, who has discussed the whole subject, and from whom I quote Bellingeri, states (‘Hist. Nat. Gen.’ tome 3 page 112) that in the Jardin des Plantes the period of the jackal has been found to be from sixty to sixty-three days, exactly as with the dog.) Tessier, who has closely attended to this subject, allows a difference of four days in the gestation of the dog. The Rev. W.D. Fox has given me three carefully recorded cases of retrievers, in which the bitch was put only once to the dog; and not counting this day, but counting that of parturition, the periods were fifty-nine, sixty-two, and sixty-seven days. The average period is sixty-three days; but Bellingeri states that this applies only to large dogs; and that for small races it is from sixty to sixty-three days; Mr. Eyton of Eyton, who has had much experience with dogs, also informs me that the time is apt to be longer with large than with small dogs.

F. Cuvier has objected that the jackal would not have been domesticated on account of its offensive smell; but savages are not sensitive in this respect. The degree of odour, also, differs in the different kinds of jackal (1/43. See Isid. Geoffroy St.-Hilaire ‘Hist. Nat. Gen.’ tome 3 page 112, on the odour of jackals. Col. Ham. Smith in ‘Nat. Lib.’ volume 10 page 289.); and Colonel H. Smith makes a sectional division of the group with one character dependent on not being offensive. On the other hand, dogs– for instance, rough and smooth terriers–differ much in this respect; and M. Godron states that the hairless so-called Turkish dog is more odoriferous than other dogs. Isidore Geoffroy (1/44. Quoted by Quatrefages in ‘Bull. Soc. d’Acclimat.’ May 11, 1863.) gave to a dog the same odour as that from a jackal by feeding it on raw flesh.

The belief that our dogs are descended from wolves, jackals, South American Canidae, and other species, suggests a far more important difficulty. These animals in their undomesticated state, judging from a widely-spread analogy, would have been in some degree sterile if intercrossed; and such sterility will be admitted as almost certain by all those who believe that the lessened fertility of crossed forms is an infallible criterion of specific distinctness. Anyhow these animals keep distinct in the countries which they inhabit in common. On the other hand, all domestic dogs, which are here supposed to be descended from several distinct species, are, as far as is known, mutually fertile together. But, as Broca has well remarked (1/45. ‘Journal de la Physiologie’ tome 2 page 385.), the fertility of successive generations of mongrel dogs has never been scrutinised with that care which is thought indispensable when species are crossed. The few facts leading to the conclusion that the sexual feelings and reproductive powers differ in the several races of the dog when crossed are (passing over mere size as rendering propagation difficult) as follows: the Mexican Alco (1/46. See Mr. R. Hill’s excellent account of this breed in Gosse’s ‘Jamaica’ page 338; Rengger ‘Saugethiere von Paraguay’ s. 153. With respect to Spitz dogs, see Bechstein’s ‘Naturgesch. Deutschlands’ 1801 b. 1 s. 638. With respect to Dr. Hodgkin’s statement made before Brit. Assoc. see ‘The Zoologist’ volume 4 for 1845-46 page 1097.) apparently dislikes dogs of other kinds, but this perhaps is not strictly a sexual feeling; the hairless endemic dog of Paraguay, according to Rengger, mixes less with the European races than these do with each other; the Spitz dog in Germany is said to receive the fox more readily than do other breeds; and Dr. Hodgkin states that a female Dingo in England attracted the male wild foxes. If these latter statements can be trusted, they prove some degree of sexual difference in the breeds of the dog. But the fact remains that our domestic dogs, differing so widely as they do in external structure, are far more fertile together than we have reason to believe their supposed wild parents would have been. Pallas assumes (1/47. ‘Acta Acad. St. Petersburgh’ 1780 part 2 pages 84, 100.) that a long course of domestication eliminates that sterility which the parent-species would have exhibited if only lately captured; no distinct facts are recorded in support of this hypothesis; but the evidence seems to me so strong (independently of the evidence derived from other domesticated animals) in favour of our domestic dogs having descended from several wild stocks, that I am inclined to admit the truth of this hypothesis.

There is another and closely allied difficulty consequent on the doctrine of the descent of our domestic dogs from several wild species, namely, that they do not seem to be perfectly fertile with their supposed parents. But the experiment has not been quite fairly tried; the Hungarian dog, for instance, which in external appearance so closely resembles the European wolf, ought to be crossed with this wolf: and the pariah dogs of India with Indian wolves and jackals; and so in other cases. That the sterility is very slight between certain dogs and wolves and other Canidae is shown by savages taking the trouble to cross them. Buffon got four successive generations from the wolf and dog, and the mongrels were perfectly fertile together. (1/48. M. Broca has shown (‘Journal de Physiologie’ tome 2 page 353) that Buffon’s experiments have been often misrepresented. Broca has collected (pages 390-395) many facts on the fertility of crossed dogs, wolves, and jackals.) But more lately M. Flourens states positively as the result of his numerous experiments that hybrids from the wolf and dog, crossed inter se, become sterile at the third generation, and those from the jackal and dog at the fourth generation. (1/49. ‘De la Longevite Humaine’ par M. Flourens 1855 page 143. Mr. Blyth says (‘Indian Sporting Review’ volume 2 page 137) that he has seen in India several hybrids from the pariah-dog and jackal; and between one of these hybrids and a terrier. The experiments of Hunter on the jackal are well-known. See also Isid. Geoffroy St.-Hilaire, ‘Hist. Nat. Gen.’ tome 3 page 217, who speaks of the hybrid offspring of the jackal as perfectly fertile for three generations.) But these animals were closely confined; and many wild animals, as we shall see in a future chapter, are rendered by confinement in some degree or even utterly sterile. The Dingo, which breeds freely in Australia with our imported dogs, would not breed though repeatedly crossed in the Jardin des Plantes. (1/50. On authority of F. Cuvier quoted in Bronn’s ‘Geschichte der Natur’ b. 2 s. 164.) Some hounds from Central Africa, brought home by Major Denham, never bred in the Town of London (1/51. W.C.L. Martin ‘History of the Dog’ 1845 page 203. Mr. Philip P. King, after ample opportunities of observation, informs me that the Dingo and European dogs often cross in Australia.); and a similar tendency to sterility might be transmitted to the hybrid offspring of a wild animal. Moreover, it appears that in M. Flourens’ experiments the hybrids were closely bred in and in for three or four generations; and this circumstance would most certainly increase the tendency to sterility. Several years ago I saw confined in the Zoological Gardens of London a female hybrid from an English dog and jackal, which even in this the first generation was so sterile that, as I was assured by her keeper, she did not fully exhibit her proper periods; but this case was certainly exceptional, as numerous instances have occurred of fertile hybrids from these two animals. In almost all experiments on the crossing of animals there are so many causes of doubt, that it is extremely difficult to come to any positive conclusion. It would, however, appear, that those who believe that our dogs are descended from several species will have not only to admit that their offspring after a long course of domestication generally lose all tendency to sterility when crossed together; but that between certain breeds of dogs and some of their supposed aboriginal parents a certain degree of sterility has been retained or possibly even acquired.

Notwithstanding the difficulties in regard to fertility given in the last two paragraphs, when we reflect on the inherent improbability of man having domesticated throughout the world one single species alone of so widely distributed, so easily tamed, and so useful a group as the Canidae; when we reflect on the extreme antiquity of the different breeds; and especially when we reflect on the close similarity, both in external structure and habits, between the domestic dogs of various countries and the wild species still inhabiting these same countries, the balance of evidence is strongly in favour of the multiple origin of our dogs.

DIFFERENCES BETWEEN THE SEVERAL BREEDS OF THE DOG.

If the several breeds have descended from several wild stocks, their difference can obviously in part be explained by that of their parent species. For instance, the form of the greyhound may be partly accounted for by descent from some such animal as the slim Abyssinian Canis simensis (1/52. Ruppel ‘Neue Wirbelthiere von Abyssinien’ 1835-40 ‘Mammif.’ s. 39 pl. 14. There is a specimen of this fine animal in the British Museum.), with its elongated muzzle; that of the larger dogs from the larger wolves, and the smaller and slighter dogs from the jackals: and thus perhaps we may account for certain constitutional and climatal differences. But it would be a great error to suppose that there has not been in addition (1/53. Even Pallas admits this; see ‘Act. Acad. St. Petersburgh’ 1780 page 93.) a large amount of variation. The intercrossing of the several aboriginal wild stocks, and of the subsequently formed races, has probably increased the total number of breeds, and, as we shall presently see, has greatly modified some of them. But we cannot explain by crossing the origin of such extreme forms as thoroughbred greyhounds, bloodhounds, bulldogs, Blenheim spaniels, terriers, pugs, etc., unless we believe that forms equally or more strongly characterised in these different respects once existed in nature. But hardly any one has been bold enough to suppose that such unnatural forms ever did or could exist in a wild state. When compared with all known members of the family of Canidae they betray a distinct and abnormal origin. No instance is on record of such dogs as bloodhounds, spaniels, true greyhounds having been kept by savages: they are the product of long-continued civilisation.

The number of breeds and sub-breeds of the dog is great; Youatt for instance, describes twelve kinds of greyhounds. I will not attempt to enumerate or describe the varieties, for we cannot discriminate how much of their difference is due to variation, and how much to descent from different aboriginal stocks. But it may be worth while briefly to mention some points. Commencing with the skull, Cuvier has admitted (1/54. Quoted by I. Geoffroy ‘Hist. Nat. Gen.’ tome 3 page 453.) that in form the differences are “plus fortes que celles d’aucunes especes sauvages d’un meme genre naturel.” The proportions of the different bones; the curvature of the lower jaw, the position of the condyles with respect to the plane of the teeth (on which F. Cuvier founded his classification), and in mastiffs the shape of its posterior branch; the shape of the zygomatic arch, and of the temporal fossae; the position of the occiput–all vary considerably. (1/55. F. Cuvier in ‘Annales du Museum’ tome 18 page 337; Godron ‘De l’Espece’ tome 1 page 342; and Col. H. Smith in ‘Nat. Library’ volume 9 page 101. See also some observations on the degeneracy of the skull in certain breeds, by Prof. Bianconi ‘La Theorie Darwinienne’ 1874 page 279.) The difference in size between the brains of dogs belonging to large and small breeds “is something prodigious.” “Some dogs’ brains are high and rounded, while others are low, long, and narrow in front.” In the latter, “the olfactory lobes are visible for about half their extent, when the brain is seen from above, but they are wholly concealed by the hemispheres in other breeds.” (1/56. Dr. Burt Wilder ‘American Assoc. Advancement of Science’ 1873 pages 236, 239.) The dog has properly six pairs of molar teeth in the upper jaw, and seven in the lower; but several naturalists have seen not rarely an additional pair in the upper jaw (1/57. Isid. Geoffroy Saint-Hilaire ‘Hist. des Anomalies’ 1832 tome 1 page 660, Gervais ‘Hist. Nat. des Mammiferes’ tome 2 1855 page 66. De Blainville (‘Osteographie, Canidae’ page 137) has also seen an extra molar on both sides.); and Professor Gervais says that there are dogs “qui ont sept paires de dents superieures et huit inferieures.” De Blainville (1/58. ‘Osteographie, Canidae’ page 137.) has given full particulars on the frequency of these deviations in the number of the teeth, and has shown that it is not always the same tooth which is supernumerary. In short- muzzled races, according to H. Muller (1/59. Wurzburger ‘Medecin. Zeitschrift’ 1860 b. 1 s. 265.), the molar teeth stand obliquely, whilst in long-muzzled races they are placed longitudinally, with open spaces between them. The naked, so-called Egyptian or Turkish dog is extremely deficient in its teeth (1/60. Mr. Yarrell in ‘Proc. Zoological Soc.’ October 8, 1833. Mr. Waterhouse showed me a skull of one of these dogs, which had only a single molar on each side and some imperfect incisors.),–sometimes having none except one molar on each side; but this, though characteristic of the breed, must be considered as a monstrosity. M. Girard (1/61. Quoted in ‘The Veterinary’ London volume 8 page 415.), who seems to have attended closely to the subject, says that the period of the appearance of the permanent teeth differs in different dogs, being earlier in large dogs; thus the mastiff assumes its adult teeth in four or five months, whilst in the spaniel the period is sometimes more than seven or eight months. On the other hand small dogs are mature, and the females have arrived at the best age for breeding, when one year old, whereas large dogs “are still in their puppyhood at this time, and take fully twice as long to develop their proportions.” (1/62. This is quoted from Stonehenge, a great authority, ‘The Dog’ 1867 page 187.)

With respect to minor differences little need be said. Isidore Geoffroy has shown (1/63. ‘Hist. Nat. General’ tome 3 page 448.) that in size some dogs are six times as long (the tail being excluded) as others; and that the height relatively to the length of the body varies from between one to two, and one to nearly four. In the Scotch deer-hound there is a striking and remarkable difference in the size of the male and female. (1/64. W. Scrope ‘Art of Deer-Stalking’ page 354.) Every one knows how the ears vary in size in different breeds, and with their great development their muscles become atrophied. Certain breeds of dogs are described as having a deep furrow between the nostrils and lips. The caudal vertebrae, according to F. Cuvier, on whose authority the two last statements rest, vary in number; and the tail in English cattle and some shepherd dogs is almost absent. The mammae vary from seven to ten in number; Daubenton, having examined twenty- one dogs, found eight with five mammae on each side; eight with four on each side; and the others with an unequal number on the two sides. (1/65. Quoted by Col. Ham. Smith in ‘Nat. Lib.’ volume 10 page 79.) Dogs have properly five toes in front and four behind, but a fifth toe is often added; and F. Cuvier states that, when a fifth toe is present, a fourth cuneiform bone is developed; and, in this case, sometimes the great cuneiform bone is raised, and gives on its inner side a large articular surface to the astragalus; so that even the relative connection of the bones, the most constant of all characters, varies. These modifications, however, in the feet of dogs are not important, because they ought to be ranked, as De Blainville has shown (1/66. De Blainville ‘Osteographie, Canidae’ page 134. F. Cuvier ‘Annales du Museum’ tome 18 page 342. In regard to mastiffs, see Col. H. Smith ‘Nat. Lib.’ volume 10 page 218. For the Thibet mastiff, see Mr. Hodgson in ‘Journal of As. Soc. of Bengal’ volume 1 1832 page 342.) as monstrosities. Nevertheless they are interesting from being correlated with the size of the body, for they occur much more frequently with mastiffs and other large breeds than with small dogs. Closely allied varieties, however, sometimes differ in this respect; thus Mr. Hodgson states that the black-and-tan Lassa variety of the Thibet mastiff has the fifth digit, whilst the Mustang sub-variety is not thus characterised. The extent to which the skin is developed between the toes varies much; but we shall return to this point. The degree to which the various breeds differ in the perfection of their senses, dispositions, and inherited habits is notorious to every one. The breeds present some constitutional differences: the pulse, says Youatt (1/67. ‘The Dog’ 1845 page 186. With respect to diseases Youatt asserts (page 167) that the Italian greyhound is “strongly subject” to polypi in the matrix or vagina. The spaniel and pug (page 182) are most liable to bronchocele. The liability to distemper (page 232) is extremely different in different breeds. On the distemper, see also Col. Hutchinson on ‘Dog Breaking’ 1850 page 279.) “varies materially according to the breed, as well as to the size of the animal.” Different breeds of dogs are subject in different degrees to various diseases. They certainly become adapted to different climates under which they have long existed. It is notorious that most of our best European breeds deteriorate in India. (1/68. See ‘Youatt on the Dog’ page 15; ‘The Veterinary’ London volume 11 page 235.) The Rev R. Everest (1/69. ‘Journal of As. Soc. of Bengal’ volume 3 page 19.) believes that no one has succeeded in keeping the Newfoundland dog long alive in India; so it is, according to Lichtenstein (1/70. ‘Travels’ volume 2 page 15.), even at the Cape of Good Hope. The Thibet mastiff degenerates on the plains of India, and can live only on the mountains. (1/71. Hodgson in ‘Journal of As. Soc. of Bengal’ volume 1 page 342.) Lloyd (1/72. ‘Field Sports of the North of Europe’ volume 2 page 165.) asserts that our bloodhounds and bulldogs have been tried, and cannot withstand the cold of the northern European forests.

Seeing in how many characters the races of the dog differ from each other, and remembering Cuvier’s admission that their skulls differ more than do those of the species of any natural genus, and bearing in mind how closely the bones of wolves, jackals, foxes, and other Canidae agree, it is remarkable that we meet with the statement, repeated over and over again, that the races of the dog differ in no important characters. A highly competent judge, Prof. Gervais (1/73. ‘Hist. Nat. des Mammif.’ 1855 tome 2 pages 66, 67.), admits “si l’on prenait sans controle les alterations dont chacun de ces organes est susceptible, on pourrait croire qu’il y a entre les chiens domestiques des differences plus grandes que celles qui separent ailleurs les especes, quelquefois meme les genres.” Some of the differences above enumerated are in one respect of comparatively little value, for they are not characteristic of distinct breeds: no one pretends that such is the case with the additional molar teeth or with the number of mammae; the additional digit is generally present with mastiffs, and some of the more important differences in the skull and lower jaw are more or less characteristic of various breeds. But we must not forget that the predominant power of selection has not been applied in any of these cases; we have variability in important parts, but the differences have not been fixed by selection. Man cares for the form and fleetness of his greyhounds, for the size of his mastiffs, and formerly for the strength of the jaw in his bulldogs, etc.; but he cares nothing about the number of their molar teeth or mammae or digits; nor do we know that differences in these organs are correlated with, or owe their development to, differences in other parts of the body about which man does care. Those who have attended to the subject of selection will admit that, nature having given variability, man, if he so chose, could fix five toes to the hinder feet of certain breeds of dogs, as certainly as to the feet of his Dorking fowls: he could probably fix, but with much more difficulty, an additional pair of molar teeth in either jaw, in the same way as he has given additional horns to certain breeds of sheep; if he wished to produce a toothless breed of dogs, having the so-called Turkish dog with its imperfect teeth to work on, he could probably do so, for he has succeeded in making hornless breeds of cattle and sheep.

With respect to the precise causes and steps by which the several races of dogs have come to differ so greatly from each other, we are, as in most other cases, profoundly ignorant. We may attribute part of the difference in external form and constitution to inheritance from distinct wild stocks, that is to changes effected under nature before domestication. We must attribute something to the crossing of the several domestic and natural races. I shall, however, soon recur to the crossing of races. We have already seen how often savages cross their dogs with wild native species; and Pennant gives a curious account (1/74. ‘History of Quadrupeds’ 1793 volume 1 page 238.) of the manner in which Fochabers, in Scotland, was stocked “with a multitude of curs of a most wolfish aspect” from a single hybrid-wolf brought into that district.

It would appear that climate to a certain extent directly modifies the forms of dogs. We have lately seen that several of our English breeds cannot live in India, and it is positively asserted that when bred there for a few generations they degenerate not only in their mental faculties, but in form. Captain Williamson (1/75. ‘Oriental Field Sports’ quoted by Youatt ‘The Dog’ page 15.), who carefully attended to this subject, states that “hounds are the most rapid in their decline;” “greyhounds and pointers, also, rapidly decline.” But spaniels, after eight or nine generations, and without a cross from Europe, are as good as their ancestors. Dr. Falconer informs me that bulldogs, which have been known, when first brought into the country, to pin down even an elephant by its trunk, not only fall off after two or three generations in pluck and ferocity, but lose the under-hung character of their lower jaws; their muzzles become finer and their bodies lighter. English dogs imported into India are so valuable that probably due care has been taken to prevent their crossing with native dogs; so that the deterioration cannot be thus accounted for. The Rev. R. Everest informs me that he obtained a pair of setters, born in India, which perfectly resembled their Scotch parents: he raised several litters from them in Delhi, taking the most stringent precautions to prevent a cross, but he never succeeded, though this was only the second generation in India, in obtaining a single young dog like its parents in size or make; their nostrils were more contracted, their noses more pointed, their size inferior, and their limbs more slender. So again on the coast of Guinea, dogs, according to Bosman, “alter strangely; their ears grow long and stiff like those of foxes, to which colour they also incline, so that in three or four years, they degenerate into very ugly creatures; and in three or four broods their barking turns into a howl.” (1/76. A. Murray gives this passage in his ‘Geographical Distribution of Mammals’ 4to 1866 page 8.) This remarkable tendency to rapid deterioration in European dogs subjected to the climate of India and Africa, may be largely accounted for by reversion to a primordial condition which many animals exhibit, as we shall hereafter see, when their constitutions are in any way disturbed.

Some of the peculiarities characteristic of the several breeds of the dog have probably arisen suddenly, and, though strictly inherited, may be called monstrosities; for instance, the shape of the legs and body in the turnspit of Europe and India; the shape of the head and the under-hanging jaw in the bull-and pug-dog, so alike in this one respect and so unlike in all others. A peculiarity suddenly arising, and therefore in one sense deserving to be called a monstrosity, may, however, be increased and fixed by man’s selection. We can hardly doubt that long-continued training, as with the greyhound in coursing hares, as with water-dogs in swimming–and the want of exercise, in the case of lapdogs–must have produced some direct effect on their structure and instincts. But we shall immediately see that the most potent cause of change has probably been the selection, both methodical and unconscious, of slight individual differences,–the latter kind of selection resulting from the occasional preservation, during hundreds of generations, of those individual dogs which were the most useful to man for certain purposes and under certain conditions of life. In a future chapter on Selection I shall show that even barbarians attend closely to the qualities of their dogs. This unconscious selection by man would be aided by a kind of natural selection; for the dogs of savages have partly to gain their own subsistence: for instance, in Australia, as we hear from Mr. Nind (1/77. Quoted by Mr. Galton ‘Domestication of Animals’ page 13.), the dogs are sometimes compelled by want to leave their masters and provide for themselves; but in a few days they generally return. And we may infer that dogs of different shapes, sizes, and habits, would have the best chance of surviving under different circumstances,–on open sterile plains, where they have to run down their own prey,–on rocky coasts, where they have to feed on crabs and fish left in the tidal pools, as in the case of New Guinea and Tierra del Fuego. In this latter country, as I am informed by Mr. Bridges, the Catechist to the Mission, the dogs turn over the stones on the shore to catch the crustaceans which lie beneath, and they “are clever enough to knock off the shell-fish at a first blow;” for if this be not done, shell-fish are well-known to have an almost invincible power of adhesion.

It has already been remarked that dogs differ in the degree to which their feet are webbed. In dogs of the Newfoundland breed, which are eminently aquatic in their habits, the skin, according to Isidore Geoffroy (1/78. ‘Hist. Nat. Gen.’ tome 3 page 450.), extends to the third phalanges whilst in ordinary dogs it extends only to the second. In two Newfoundland dogs which I examined, when the toes were stretched apart and viewed on the under side, the skin extended in a nearly straight line between the outer margins of the balls of the toes; whereas, in two terriers of distinct sub- breeds, the skin viewed in the same manner was deeply scooped out. In Canada there is a dog which is peculiar to the country and common there, and this has “half-webbed feet and is fond of the water.” (1/79. Mr. Greenhow on the Canadian Dog in Loudon’s ‘Mag. of Nat. Hist.’ volume 6 1833 page 511.) English otter-hounds are said to have webbed feet: a friend examined for me the feet of two, in comparison with the feet of some harriers and bloodhounds; he found the skin variable in extent in all, but more developed in the otter-hounds than in the others. (1/80. See Mr. C.O. Groom-Napier on the webbing of the hind feet of Otterhounds in ‘Land and Water’ October 13, 1866 page 270.) As aquatic animals which belong to quite different orders have webbed feet, there can be no doubt that this structure would be serviceable to dogs that frequent the water. We may confidently infer that no man ever selected his water-dogs by the extent to which the skin was developed between their toes; but what he does, is to preserve and breed from those individuals which hunt best in the water, or best retrieve wounded game, and thus he unconsciously selects dogs with feet slightly better webbed. The effects of use from the frequent stretching apart of the toes will likewise aid in the result. Man thus closely imitates Natural Selection. We have an excellent illustration of this same process in North America, where, according to Sir J. Richardson (1/81. ‘Fauna Boreali-Americana’ 1829 page 62.), all the wolves, foxes, and aboriginal domestic dogs have their feet broader than in the corresponding species of the Old World, and “well calculated for running on the snow.” Now, in these Arctic regions, the life or death of every animal will often depend on its success in hunting over the snow when soft; and this will in part depend on the feet being broad; yet they must not be so broad as to interfere with the activity of the animal when the ground is sticky, or with its power of burrowing holes, or with other necessary habits of life.

As changes in domestic breeds which take place so slowly are not to be noticed at any one period, whether due to the selection of individual variations or of differences resulting from crosses, are most important in understanding the origin of our domestic productions, and likewise in throwing indirect light on the changes effected under nature, I will give in detail such cases as I have been able to collect. Lawrence (1/82. ‘The Horse in all his Varieties, etc.’ 1829 pages 230, 234.), who paid particular attention to the history of the foxhound, writing in 1829, says that between eighty and ninety years before “an entirely new foxhound was raised through the breeder’s art,” the ears of the old southern hound being reduced, the bone and bulk lightened, the waist increased in length, and the stature somewhat added to. It is believed that this was effected by a cross with a greyhound. With respect to this latter dog, Youatt (1/83. ‘The Dog’ 1845 pages 31, 35; with respect to King Charles’ spaniel page 45; for the setter page 90.), who is generally cautious in his statements, says that the greyhound within the last fifty years, that is before the commencement of the present century, “assumed a somewhat different character from that which he once possessed. He is now distinguished by a beautiful symmetry of form, of which he could not once boast, and he has even superior speed to that which he formerly exhibited. He is no longer used to struggle with deer, but contends with his fellows over a shorter and speedier course.” An able writer (1/84. In the ‘Encyclop. of Rural Sports’ page 557.) believes that our English greyhounds are the descendants, PROGRESSIVELY IMPROVED, of the large rough greyhounds which existed in Scotland so early as the third century. A cross at some former period with the Italian greyhound has been suspected; but this seems hardly probable, considering the feebleness of this latter breed. Lord Orford, as is well-known, crossed his famous greyhounds, which failed in courage, with a bulldog–this breed being chosen from being erroneously supposed to be deficient in the power of scent; “after the sixth or seventh generation,” says Youatt, “there was not a vestige left of the form of the bulldog, but his courage and indomitable perseverance remained.”

Youatt infers, from a comparison of an old picture of King Charles’s spaniels with the living dog, that “the breed of the present day is materially altered for the worse:” the muzzle has become shorter, the forehead more prominent, and the eyes larger; the changes in this case have probably been due to simple selection. The setter, as this author remarks in another place, “is evidently the large spaniel improved to his present peculiar size and beauty, and taught another way of marking his game. If the form of the dog were not sufficiently satisfactory on this point, we