16 THE TUNDRA AND ITS FAUNA 
dies away into forest. The result is that the continental 
tundra forms a band of very varying width. The mild- 
ness of the Western European climate pushes the tree 
limit up within the Arctic Circle, and reduces the tundra 
zone to a narrow band to the north of Scandinavia. 
Thence it extends through European Russia into 
Siberia, and reappears again at the other side of the 
Bering Strait to extend across Arctic America. Here 
to the east it revenges itself for its conquest by the 
forest in Western Europe by pushing the forest zone 
far to the south, so that a band of tundra extends 
down the coast-line of Labrador, and even into New- 
foundland. 
The northern limit of the continental tundra is the 
polar sea, but the tundra type reappears on the margin 
of the land-masses lying within that sea. The islands 
of the American archipelago, Baffin Land, Greenland, 
the northern shore of Iceland, Spitsbergen, Franz 
Josef Land, Nova Zembla, the New Siberian Islands, 
&c., are all fringed by a band of tundra. Its northern 
extension may indeed be gathered from the fact that 
the reindeer, one of the most characteristic tundra 
animals, was hunted by the Sverdrup expedition in 
King Oscar Land, which extends to about 80° 30’ 
N. lat. In these regions the sea again forms one of the 
boundaries of the tundra zone. The other boundary is 
formed by the presence of eternal ice and snow. Gener- 
ally it may be said that tundra occurs wherever the 
melting of the snow is sufficient to expose a surface 
upon which land plants may grow. 
The climate throughout this great area naturally 
varies, but the special features are the following. 
Nowhere does the mean temperature of the warmest 
- month exceed 50° F., and it is often much below this. 
