322 I'HE TUNDRAS AND STEPPES OF PREHISTORIC EUROPE. 



The arctic lands of Eurasia and North America show two well- 

 marked zones — a zone of treeless wastes bordering the Polar Sea, and 

 a coniferous forest zone lying immediately to the south. The treeless 

 wastes are known as tundras in Europe and Asia, and as barren 

 grounds in North America. These form plains of immense extent, but 

 of very unequal width from north to south. In Eurasia they lie for the 

 most part north of the Arctic Circle, while in North America they 

 range upon the whole considerably farther south, reaching the sixtieth 

 parallel on the western shores of Hudson Bay. Their southern 

 boundary, however, is in both Old and New Worlds exceedingly irreg- 

 ular. Where the flat lands are exposed to the full sweep of the north- 

 ern blasts, tundra conditions advance far to the south, invading the 

 forest zone in narrower or broader stretches. Indeed, even within the 

 region of arctic forests isolated patches and wider areas of tundra are 

 encountered. In other places more sheltered from the fierce winds 

 coming from the polar seas, the arctic forests in their turn enci'oach 

 upon the tundras, so as nearly to reach the shores of the frozen ocean. 

 Such is the case in the valleys of the Yenesei, the Khatanga, the 

 Olenek, the Lena, and other North Siberian rivers. Similarly in North 

 America the arctic forests straggle down the valleys of the Mackenzie 

 and other rivers to beyond the Arctic Circle. 



Mosses and lichens form the prevailing vegetation of the tundras — 

 marshes and bogs extending over vast areas in spring and- summer, 

 while the less marshy tracts are carpeted with gray lichens. Here and 

 there, too, in sheltered spots, dwarf birch and willow scrub sprinkle 

 the surface or flourish in denser masses, and ever and anon more or less 

 wide stretches of meadow put in an appearance. Now and again the 

 interminable plains give place to rolling ground, the low hills and 

 knolls being not infrequently clothed with dwarf trees. No hard 

 and fast line, indeed, can be drawn between the tundras and the arctic 

 forests. The two regions not only interosculate, but numerous oases of 

 trees are encountered in the tundras along their southern margin, 

 while equally numerous patches of tundra, as already mentioned, are 

 met with farther south within the arctic zone. It may be added that 

 in northern Siberia bare rocky hills and mountains — highly fissured, 

 and showing many gullies, ravines, and debris-strewn valleys — now 

 and again treak the uniformity of a tundra landscape. 



A word or two now as to the characteristic animals of the tundras 

 and barren grounds. First among these come the arctic lemmings. 

 They feed on grass roots and stalks, mosses, reindeer linchens, and the 

 shoots of the dwarf birch, for which in winter they tunnel through the 

 turf or under the snow. The banded lemming is an especially charac- 

 teristic form, since it is confined to the maritime tracts of Eurasia and 

 the adjacent islands, and the corresponding areas of North America, 

 and is never met with in the forest zone. The Obi lemming has a 

 similar distribution, but ranges somewhat farther south, and not quite 



