Fur seals are extremely polygamous and the old males, which weigh from 400 to 500 pounds, “haul up” first on the breeding beaches. Each bull holds a certain area, and as the females, only one-fifth his size, come ashore they are appropriated by the nearest bulls until each “beach master” gathers a harem, sometimes containing more than 100 members. Here the young are born, and after the mating season the seals, which have remained ashore without food from four to six weeks, return to the water. The mothers go and come, and each is able to find her young with certainty among thousands of apparently identical woolly black “pups.” From the ages of one to four years fur seals are extremely playful. They are marvelous swimmers and frolic about in pursuit of one another, now diving deep and then, one after the other, suddenly leaping high above the surface in graceful curves, like porpoises. Squids and fish of various species are their main food. Their chief natural enemy is the killer whale, which follows their migrations and haunts the sea about their breeding grounds, taking heavy toll among them. Since the discovery of the Pribilof Islands by the Russians the fur seal herds there have yielded more than five million recorded skins. A census of the herds in 1914 gave these islands nearly three hundred thousand seals. Now that pelagic sealing has been suppressed and the herds are being protected, there is every reason to expect that the seals will increase rapidly to something like their former numbers. STELLER SEA-LION (Eumetopias jubata) Sea-lions are near relatives of the fur seals and have a nearly similar distribution, both in far southern and northern seas. The males of the several species are more than twice the size of the females and are characterized by an enormous development of neck and shoulders. The Steller sea-lion is the largest member of the group, the old bulls weighing from 1,200 to 1,500 pounds. All are extremely gregarious and polygamous. The Steller sea-lions belong to the North Pacific, whence they range in winter as far south as the coasts of California and Japan. In spring they migrate northward to their breeding grounds among the Aleutian, Pribilof, and other rocky islands of the North Pacific. The early histories of this region record their great abundance, including several hundred thousand which were reported to have congregated to breed each season on the Pribilof Islands. Although less valuable than the fur-seal, persistent hunting has gradually reduced their numbers on these islands until in 1914 only a few hundred remained. In summer range they are less limited than the fur seals, occurring in herds about the shores of many rocky islands along the mainland coast of the North Pacific and the Aleutian chain.