In former days it is probable that the polar bear ranged considerably farther south than is the case at the present day, when it is but rarely seen even in the south of Greenland. The species, like Arctic animals generally, has a nearly circumpolar distribution, and has been divided into a number of local races. These are at present distinguished by skull-characters, but if a sufficient series of skins were available in museums for comparison, there would probably be found local differences in the colour, length, and character of the fur. Polar bear skins are, however, of great commercial value, so that no collection contains a large series of specimens. Moreover, the exact locality of most of the skins offered for sale by furriers is unknown. Against the intense cold of its Arctic home the white bear is well protected by its long and dense coat, as well as by the thick layer of fat underlying the skin. By means of the hairy covering of the soles of the feet--which in other bears are naked--the animal is enabled to obtain a firm foothold on the ice; upon which, as well as on land, it is a swift and long-winded runner. As special adaptations in the bodily form to swimming and diving, may be mentioned the thin, compressed body, the long neck, the small ears, and the long pointed head, which offer the least possible resistance to progression in water. The strong limbs, with broad paws and webs between the toes, form efficient oars when swimming; while the oily nature of the fur keeps the water off the body. The white bear is, in fact, as admirably adapted to a life among the Arctic ice as is the lion to the deserts of Africa; and both animals may be regarded as the absolute rulers of their respective domains. [Illustration] In the pursuit of its prey the polar bear displays great craft and ingenuity. When it spies a seal sleeping by a hole in the ice, or on the edge of an ice-floe, if it succeeds in approaching undetected, it glides swiftly and silently into the water, swims a certain distance under the surface, and then rises to observe the situation of its victim. In this manner, by alternate dives and risings, it progresses till within a short distance, when it makes a final dive, to rise near the sleeping seal, which it generally manages to capture. In summer these bears are almost complete vegetarians, subsisting on grass, berries, lichens, moss, and sea-weed. At other seasons their chief food consists of the flesh of seals, walruses, and the smaller cetaceans, such as the white whale and the so-called blackfish. In some districts they capture fish of various kinds, and more especially salmon. In addition to the above, numbers of the smaller polar mammals, such as the Arctic lemming, are caught and eaten; while the young and eggs of various sea-birds, especially auks and guillemots, also form a portion of the diet.