But however their outward aspects may differ, they are of the same blood and know it. A featherweight bantam cock will stand up to an elephantine brahma and fight him according to the rules of the ring and next minute pay compliments to his lady in language which she will be at no loss to understand. And if the artificial conditions of their life were removed, they would soon all lapse alike to the image of the stock from which they are sprung. This is well illustrated in a show case in the South Kensington Museum exhibiting a group of fowls from Pitcairn's Island. These are descended from some stock landed by the mutinous crew of H.M.S. Bounty in 1790, which ran wild, and in a century they have gone back to the small size and lithe figure and almost to the game colour of the wild birds from which they branched off before history dawned.
If we turn next to the Ruminants, the clean beasts which chew the cud and divide the hoof, the puzzle becomes harder still. Deer and antelopes are often kept as pets, and become so tame that they are allowed to wander at liberty. In Egypt herds of gazelles were so kept before the days of Cheops. In India I have known a black buck which regularly attended the station cricket ground, moving among the nervous players with its nose in the air and insolence in its gait, fully aware that eighteen-inch horns with very sharp points insured respectful treatment. Mr. Sterndale trained a Neilghai to go in harness. The great bovine antelopes of Africa would become as tame, and there is no reason to suppose that their beef and milk would not be as good as those of the cow. But no antelope or deer appears ever to have been domesticated, with the exception of the reindeer.
Of the other ruminants the ox, buffalo, yak, goat, sheep and a few others are domestic animals, while the bison and the gaur, or so-called Indian bison, and a large number of wild goats and sheep have been neglected. The buffalo and yak have probably come under the yoke in comparatively recent times, for they are little changed; but the goat and still more the sheep have undergone a wonderful transformation within and without. Who could recognise in a Leicester ewe the wary denizen of precipitous mountains which will not feed until it has set a sentinel to give warning if danger approaches? And here is a curious fact which has scarcely been noticed by naturalists.
The original of our goat is supposed to be the Persian ibex. At any rate, it was an ibex of some species, as its horns plainly show. But on the plains of Northern India, under ranges of hills on which the Persian ibex wanders wild, the common domestic goat is a very different animal from that of Europe, and has peculiar spiral horns of the same pattern as the markhor, another grand species of wild goat which draws eager hunters to the higher reaches of the same mountains. From this it would appear that two species of wild goat have been domesticated and kept to some extent distinct, one eventually finding its way westward, but not eastward and southward.
The Indian humped cattle also differ so widely in form, structure and voice from those of Europe that there can scarcely be a doubt of their descent from distinct species. But both have entirely disappeared as wild animals, unless indeed the white cattle of Chillingham are really descendants of Caesar's dreadful urus and not merely domestic cattle lapsed into savagery. So have the camel, and, with a similar possible exception, the horse. Was the whole race in each of these cases subjugated, or exterminated, and that by uncivilised man with his primitive weapons? There is no analogy here with the extinction of such animals as the mammoth, for the ox is a beast in every way fitted to live and thrive in the present condition of this world, as much so as the buffalo and the Indian bison, which show no sign of approaching extinction. Our fathers easily got rid of the difficulty by assuming that Noah never released these species after the Flood, but what shall those do who cannot believe in the literality of Noah's ark?
As for the dog, its domestication has been the creation of a new species. The material was perhaps the wolf, more likely the jackal, but possibly a blend of more than one species. But a dog is now a dog and neither a wolf nor a jackal. A mastiff, a pug, a collie, a greyhound, a pariah all recognise each other and observe the same rules of etiquette when they meet.
We must admit, however, that, whatever pliability of disposition, or other inherent suitability, led to the first domestication of certain species of animals, the changes induced in their natures by many generations of domesticity have made them amenable to man's control to a degree which puts a wide difference between them and their wild relations. A wild ass, though brought up from its birth in a stable, would make a very intractable costermonger's moke. We may infer from this that the first subjugation of each of our common domestic animals was the achievement of some genius, or of some tribe favourably situated, and that they spread from that centre by sale or barter, rather than that they were separately domesticated in many places. This would partly explain why a few species of widely different families are so universally kept in all countries to the exclusion of hundreds of species nearly allied and apparently as suitable. When a want could be supplied by obtaining from another country an animal bred to live with man and serve him, the long and difficult task of softening down the wild instincts of a beast taken from the forests or the hills and acclimatising its constitution to a domestic life was not likely to be attempted.
But there have been a few recent additions to our list of domestic animals. The turkey and the guinea fowl are examples, and perhaps within another generation we may be able to add the zebra. And there may be many other animals fitted to enrich and adorn human life which would make no insuperable resistance to domestication if wisely and patiently handled. Here is a noble opening for carrying out in its kindest sense the command, "Multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the face of the earth."