The extreme eastern regions of the Amur basin and Russian Manchuria, being warmer, more humid and fertile, also abound more in animal life than the other parts of Asiatic Russia. On the other hand, the Siberian bear, deer, roebuck, hare, squirrel, marmot and mole are about one-third larger, and often half as heavy again as their European congeners. This is doubtless due partly to the greater abundance of nourishment along the rivers and shores of Siberia, and partly to the fact that for ages the western species have been more preyed upon by man, living in a constant state of fear, and mostly perishing before attaining their full development. The Arctic Seas abound probably as much as the Pacific Ocean with marine animals. Nordenskjoeld found the Siberian waters very rich in molluscs and other lower organisms, implying a corresponding abundance of larger animals. Hence fishing, perhaps more than navigation, will be the future industry of the Siberian coast populations. Cetacea, fishes, molluscs, and other marine organisms are cast up in such quantities along both sides of Bering Strait that the bears and other omnivorous creatures have here become very choice as to their food. But on some parts of the coast in the Chukchi country whales are never stranded, and since the arrival of the Russians certain species threaten to disappear altogether. The _Rhytina stelleri_, a species of walrus formerly frequenting Bering Strait in millions, was completely exterminated between the years 1741-68. Many of the fur-bearing animals, which attracted the Cossacks from the Urals to the Sea of Okhotsk, and which were the true cause of the conquest of Siberia, have become extremely rare. Their skins are distinguished, above all others, for their great softness, warmth, lightness, and bright colours. The more Alpine or continental the climate, the more beautiful and highly prized become the furs, which diminish in gloss towards the coast and in West Siberia, where the south-west winds prevail. The sables of the North Urals are of small value, while those of the Upper Lena, fifteen degrees farther south, are worth a king's ransom. Many species assume a white coat in winter, whereby they are difficult to be distinguished from the surrounding snows. Amongst these are the polar hare and fox, the ermine, the campagnol, often even the wolf and reindeer, besides the owl, yellow-hammer, and some other birds. Those which retain their brown or black colour are mostly such as do not show themselves in winter. The fur of the squirrels also varies with the surrounding foliage, those of the pine forests being ruddy, those of the cedar, _taiga_, and firs inclining to brown, and all varying in intensity of colour with that of the vegetation.