DOG. 353 DOG. The Siberian wild dog (Cants alpinus) much resembles the others iu features and liabits. It inhabits the forested regions of northern Asia as far south as the Altai Mountains, and sub- sists 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 fox- red lor a long and woolly winter dress of yellow- ish white, lis 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 Hinuilayaa wild dog. Al- though numerous in wild packs, it is also kept domesticated by the native Australians, by whose remote ancestors it was probably introduced to that island from the North. See Disco. INTERBREEDING. TaM.^BII.ITY, AND VolCE, 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 inter- breed and produce offspring. This has been accomplished in the case of some species in eap- tivitv 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. In respect to tamability. canine animals are much superior as a tribe to feline animals, and jjerhaps no species intelligently tried has proved intractable. Pet examples of almost every spe- cies 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 prac- tices, a svmpathctic 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 men- tioned — to bay when pursuing quarry; but none truly harks. Much attention was paid to this point bv Mr. Bartlett. for many years keeper of the Zoiilogical Cardeiis 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 quickl.v fall by imitation. "A well-known instance of this," Mr. Bartlett wrote I Proreedinfis of the Zoriloqical Society of J,ondnn, ISOO), "occurred under my notice. A wild ant- arctic wolf, after a few months, hearing the bark- ing of dogs in the immediate neighborhood, be- gan to bark, and succeedeil admirably. The same thing has happened to my knowledge in the case of purebred Eskimo dogs and dingos." See Plates of Wolves and Wild Dogs; and Foxes AND Jackals. Fossil Dogs. The ancestors of the dogs. wolves, fo.xes, and jackals maj' 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 ditliculty be placed in their respective categories, or .separated from the ancestors of the civets and bears. Indeed, these families, together with the Canidie, had a connuon origin in the Eocene carnivores, such as Amphicyon, Calecynus, Cjtio- dictis, which are synthetic types. The modern family of C'anidse is a diphyletic group, i. e. it has had two sources. One scries, terminating in the jackal, is thought to have had a common origin with the Viverrida^ in Cynodiotis. The sec- ond series, comprising the true dogs, fo.xes, and wolves, traces its ancestry from Dapha^nus and the earlier Amphicyon, which latter also gave rise to the bears. OeioIN of Domestic Dogs. A great amount of discussion has taken place over the question of the origin of domestic dogs — whether they repre- sent 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 else- where known among mammals, and some have narrow skulls with prolonged jaws, while in others the width of the skull is greater than its anteroposterior length, and the jaws hardly pro- trude 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 spe- cies; and, if so, what traces remained to indicate what that species is, or was? It would be un- profitable 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 modem 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 uni- versal, and seem comparatively unimportant. Probably the most singular characteristic pos- sessed 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 com- pletely. See Dingo. The consensus of modem 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 man- kind, have lieen intermixed until only an indefi- nite 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 W(df; 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 crossbreed with dogs is now
