DOG. The Siberian wild dog (Canis alpinus) much resembles the others in features and habits. It inhabits the forested regions of northern Asia as far south as the Altai Mountains, and subsists almost entirely on deer, which it hunts in companies, pursuing them so constantly that it is said occasionally to destroy or drive away all the deer in certain districts. It also hunts the ibex in the high mountains. It appears that this semi-arctic dog changes its summer coat of foxred for a long and woolly winter dress of yellowish white, as do the arctic foxes. There remains to be mentioned the dingo (Canis dingo), which by some naturalists has been set apart in a genus (Dingo) by itself. It inhabits Australia only, and bears a considerable resemblance to the Himalayan wild dog. Although numerous in wild packs, it is also kept domesticated by the native Australians, by whose remote ancestors it may have been introduced into that island from the North. See DINGO. INTERBREEDING, TAMABILITY, AND VOICE. A few special considerations may well be made at this point, as tending to illuminate the relation which domestic dogs bear to the wild forms. First, it appears certain, although it may almost never occur under natural conditions, where the primal instincts of kinship prevent crossing of 'species,' that all the various canine animals may interbreed and produce offspring. This has been accomplished in the case of some species in captivity or a state of semi-domestication. Whether these hybrid offspring are fertile with each other in every case, or usually, is not so certain. A few instances are recorded in which they have been found to be so. 353 In respect to tamability, canine animals are much superior as a tribe to feline animals, and perhaps no species intelligently tried has proved intractable. Pet examples of almost every species have been found among the savage or partly civilized peoples of the world, and the owners of menageries find even wolves submitting well to the trainers. There seems to be in the canine nature, disposing them to gather in packs and hunt in concert, and strengthened by these practices, a sympathetic element wanting in most other carnivores, the cultivation of which by man has led to the close affiliation between him and his dog, and to the expansion of the dog nature into the beautiful fidelity, appreciation, and affection it exhibits in its higher examples. Wild canines may be said to howl, to yelp, to whine, to growl, and even-as some have mentioned-to bay when pursuing quarry; but none truly barks. Much attention was paid to this point by Mr. Bartlett, for many years keeper of the Zoological Gardens of London, who concluded from his observation of the captives, of many wild species, under his care, that the barking of domestic dogs is an acquired habit, but one into which wild canines quickly fall by imitation. "A well-known instance of this," Mr. Bartlett wrote (Proceedings of the Zoological Society of London, 1890), "occurred under my notice. A wild antarctic wolf, after a few months, hearing the barking of dogs in the immediate neighborhood, began to bark, and succeeded admirably. The same thing has happened to my knowledge in the case of pure-bred Eskimo dogs and dingos." See Plates of WOLVES AND WILD DOGS; and FOXES AND JACKALS. FOSSIL DOGS. The ancestors of the dogs, DOG. wolves, foxes, and jackals may be traced back through the Pliocene into the Miocene and Eocene periods, beyond which the ancestral forms become so generalized in type that they can with difficulty be placed in their respective categories, or separated from the ancestors of the civets and bears. Indeed, these families, together with the Canidæ, had a common origin in the Eocene carnivores, such as Amphicyon, Calecynus, Cynodictis, which are synthetic types. The modern family of Canidæ is a diphyletic group, i. e. it has had two sources. One series, terminating in the jackal, is thought to have had a common origin with the Viverrida in Cynodictis. The second series, comprising the true dogs, foxes, and wolves, traces its ancestry from Daphænus and the earlier Amphicyon, which latter also gave rise to the bears. ORIGIN OF DOMESTIC DOGS. A great amount of discussion has taken place over the question of the origin of domestic dogs-whether they represent a separate species, or are the descendants of some existing canine species, or are of composite stock. The present diversity is so great that some dogs are no larger than the heads of others; that some are almost totally hairless, while others wear coats of hair longer than is elsewhere known among mammals, and some have narrow skulls with prolonged jaws, while in others the width of the skull is greater than its antero-posterior length, and the jaws hardly protrude beyond the forehead. Equally remarkable differences separate them temperamentally. The question then arose: Could all these variations be accounted for as the result of domestication and selective breeding acting upon a single species; and, if so, what traces remained to indicate what that species is, or was? It would be unprofitable to enter into all the speculations that have been recorded. Some have held that our dogs were only modified descendants of a wolf, the same or essentially similar to the modern common wolf; others, that all dogs are modified jackals. It has been extremely difficult for either school to find characteristics held in common by all varieties of dogs by which to make their comparisons and support their arguments. The up-curling of the tail, the drooping of the ears, the presence of buttons' of tan over the eyes, and other alleged characteristics are not universal, and seem comparatively unimportant. Probably the most singular characteristic possessed by dogs as contrasted with wild canines of every sort is a matter of voice-the bark; but those on the borderland of dogdom, such as the Arctic sledge-dogs and the dingo, do not utter this peculiar sound, and, on the other hand, dingos, Eskimo dogs, and even wild canines, quickly acquire the habit when associated with tame dogs, by imitating them more or less completely. See DINGO. The consensus of modern scientific opinion is that our dogs represent the union of several strains, which during the long ages since this animal began to associate with wandering mankind, have been intermixed until only an indefinite trace of the original wild ancestry can be found; and that this process has continued to the present time. An important element, no doubt, is wolf; an equally important element, jackal. Foxes seem to have had a less part in the mixture, but the former assertion that foxes were unable to cross-breed with dogs is now known to be erroneous; such hybrids are uncommon, but do exist, and are no less fertile than other canine crosses, such, for instance, as those between domestic dogs and wolves or jackals, which constantly happen on the frontier of civilization, both by accident and by intention on the part of the owners. But it must be remembered that wolves and jackals are of various species and exist in many parts of the world, and that there are various other members of the dog family, such as the 'wild dogs' of the Orient, described earlier in this article, the foxes, and the fox-dogs and wolves of South America. More over, sufficient time has elapsed in all probability since the domestic races began for species of a smaller sort to have become extinct, perhaps largely through man's agency, partly by killing them, and partly by absorbing them into his domestic family. The peculiarities of certain races, such as the Japanese pugs and the hairless dogs of tropical America, are so great as to be accounted for with difficulty, except upon the supposition that they are the descendants of extinct species. All canine animals exhibit, more or less plainly, the qualities which have contributed to make the character and value of the domestic dog what they are. They are courageous, quickwitted, and accustomed to possessing and defending home and property (their captures), and to the exercise of both nose and eyes, whose faculties are highly developed. More important, however, as rendering them susceptible to taming and the offer of human friendship, is their practice of hunting in companies and aiding one another, which has developed in them a social disposition much in excess of that in any other class of carnivores, and given them a sense of mutual dependence easily transferred to human companions and increased by continual human association. Hence the fact that in every part of the world, and from time immemorial, men have been found to own dogs, and the history of the dispersion of his dogs is bound up with the problem of the dispersion of man himself. The practice appears as far back as humanity can be traced. We may not be sure that Paleolithic man kept dogs as camp-mates, but 'Neolithic' man, he of the stone village on the hill and of the pile-built dwelling on the lake, certainly possessed and used them as an aid in keeping his flocks and herds. The oldest monumental remains of the valleys of the Indus, the Euphrates, and the Nile, show that dogs were common among these early peoples and in great diversity. Certain types well known to-day may be recognized, and will be referred to more particularly in the special articles on those breeds. Consult Berjeau, The Varieties of Dogs (London, 1865), a treatise upon dogs as they are found depicted in old sculptures, pictures, engravings, and books to the end of the seventeenth century. It is certain that the first ones tamed were of local species, some of which in all probability have since become extinct. As tribes enlarged and spread out, their dogs would go with them. Here and there they would encounter and coalesce with other peoples and an intermingling of dogs would follow. This, going on indefinitely and complicated by constant intermixture with new blood from the forest-for in no group of animals is interfertility more general-would speedily bring about a great variety of forms. In addition to this, however, there must have gone on from the very first, besides the varying influences of new climate, food, and general environment, a certain amount of selective breeding. It has been held by Professor Shaler and others that the first motive leading to domestication of the dog was to provide a resource against the recurring famines that afflict aboriginal life, while others suppose the animal's aid in hunting first made it valuable. Undoubtedly, then as row, the dog was eaten on occasion, but it would certainly make itself so useful as a watch-dog and a hunter as quickly to win regard; and there is no doubt that the personality of the animal would appeal to the affection of the primeval savages as it does to-day. No other human beings are regarded as so rude and autochthonous as the northern Australians, yet while they eat both the wild and tame dingos, and use the latter in hunting, they regard many of them as pets, lavish affection upon them, and even nurse the puppies at the women's breasts. In recognition of these qualities, the best or most interesting puppies and older dogs would naturally be saved when any were to be killed for food or other purpose. In such isolated circumstances as those of the Australians, where there is free and constant intercourse between the wild stock and the tame, this would have little effect; but in general, where the mixture of several wild breeds had already produced diverse hybrids, the unconscious selection thus brought about would soon be effective, and would be followed, as civilization began, with a more intelligent and definite kind of choice, which must have originated selective breeding long before any history of it begins. It must have been intelligently and persistently practiced, in fact, long before the earliest civilized records, for monuments inscribed four or five thousand years ago bear pictures of widely diversified and perfectly bred races of dogs, such as greyhounds. VARIETIES OF DOMESTIC DOGS. No one probably has ever attempted to make a complete catalogue 2 3 6 YOY GROWTH OF A DOG'S TEETH. Development of dentition in the lower jaw at various successive ages: 1, two days; 2, four months; 3, six months; 4, nine months; 5, eleven months; 6, four years. of the varieties of domestic dogs known throughout the world, but Fitzinger estimated the number in 1876 at about 185. All these fall into certain groups, or types, as will presently be noted; and the study of their points of likeness and unlikeness has been made by several recent investi |