172 THE GEOGRAPHY OF PLANTS. 



sea lions, penguins, and petrels. Cattle are 

 exceedingly fond of this grass, which yields 

 annually a much greater supply of excellent 

 fodder than the same extent of ground would 

 do either of common grass or clover. 



5. The Sub-arctic Zone stretches, from 58 

 lat. to the arctic circle, and its average mean 

 temperature is between 39 and 42 Fahr., but 

 this varies exceedingly in different localities. 

 It embraces in the northern hemisphere, Nor- 

 way, Sweden, Finland, the north of Russia, 

 Iceland, part of Siberia, the more northerly 

 portion of North ^America, and the south of 

 Greenland ; in the southern hemisphere, only a 

 few barren and small islands extend into this 

 ^one. It is the region of the firs and willows ; 

 the beech, oak, and pine, or Scotch fir, will not 

 flourish within it, or rather not beyond 60 

 N. lat., though on the western coast of Norway, 

 under peculiar circumstances, the pine has 

 been found as far as 70 N. lat. In the interior, 

 the noble fir appears in its place. Prodigious 

 forests of these are spread over the mountains 

 of Norway and Sweden ; and in European 

 Kussia alone, 200,000,000 acres are clothed 

 with pines and firs alone, or occasionally mixed 

 with willow, poplars, and alders. In very 

 many places, on both the Swedish and Norwe- 

 gian mountains, these forests are not accessible, 

 and they are of value only when situated near 

 a river, or an arm of the sea. The Gulf of 

 Bothnia is surrounded by one vast, contiguous, 

 unbroken forest, as old as the world, and con^ 



