These statements certainly tend to show that there is no actual improbability in supposing that many wild species of _Canidæ_ have at different times, and by different nations, been tamed and gradually modified into true domestic Dogs. But the most significant fact bearing upon the multiple origin of the Dog is the often-occurring close resemblance between the domestic Dog of a savage tribe and the wild species of _Canis_ inhabiting the same district. Of this most important circumstance there are far too many instances to allow of its being looked upon as a mere coincidence. Sir John Richardson says: “The resemblance between the Wolves and the Dogs of those Indian nations who still preserve their ancient mode of life continues to be very remarkable, and it is nowhere more so than at the northern extremities of the Continent, the Eskimo Dogs being not only extremely like the Grey Wolves of the Arctic circle in form and colour, but also nearly equalling them in size. The Dog has generally a shorter tail than the Wolf, and carries it more frequently curled over the hip, but the latter practice is not totally unknown to the Wolf, although that animal, when under the observation of man, being generally apprehensive of danger or on the watch, seldom displays this mark of satisfaction.” And again, “The resemblance between the northern Wolves and the domestic Dog of the Indians is so great, that the size and strength of the Wolf seem 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 an Indian fails at times to discriminate them.” As the Eskimo and Indian Dogs resemble the North American Wolf (_C. lupus_), so the Dog of the Hare Indians, a very distinct breed (see below), resembles the Prairie Wolf (_C. latrans_). So great is this resemblance that Richardson says, “I could detect no marked difference in form except the smallness of its [the Dog’s] cranium, nor in the fineness of its fur, and arrangement of its spots of colour. The length of the fur on the neck, back part of the cheeks, and top of the head, was the same in both species. It, in fact, bears the same resemblance to the Prairie Wolf that the Eskimo Dog does to the great Grey Wolf.” Another observer remarks that, except in the matter of barking, there is no difference whatever between the black Wolf-dog of the Indians of Florida and the Wolves of the same country. The Dogs also breed readily with the wild animals they so closely resemble. The Indians often cross their Dogs with Wolves to improve the breed, and in South America the same process is resorted to between the domesticated and the wild Dogs.