THE ARCTIC FAUNA. 133 



There are six typical Polar Land-mammals, one of 

 which, the Polar Bear, is semi-aquatic. The Reindeer 

 (Rangifer tarandus) occurs upon almost all the polar 

 lands, and it has often been a source of speculation 

 in what manner it has reached such remote islands as 

 Spitsbergen and Novaya Zemlya the former of the 

 two being so remote from a continent. There is no 

 doubt that Reindeer are great wanderers, owing to 

 the difficulty of rinding sufficient food-supply for the 

 large herds in which they are accustomed to travel ; 

 and for this reason they can cross, and have been 

 known to cross, distances of from ten to twenty miles 

 on ice. The Behring Straits, when frozen over in 

 winter, is frequently traversed by them. But I quite 

 agree with Dr. Brauer (p. 260) that it is impossible to 

 account for their presence in Spitsbergen by an im- 

 migration from either Novaya Zemlya, Greenland, or 

 Scandinavia, under the present geographical con- 

 ditions. The seas between the former island and 

 the other land-masses referred to are rarely entirely 

 frozen over. Even if this should occur, the dis- 

 tances between Spitsbergen and Greenland, Novaya 

 Zemlya, or Scandinavia are so great, that a migration 

 across ice is quite excluded from the range of pos- 

 sibilities, since Reindeer could not subsist without 

 food during the time it would take to travel from 

 one to the other. The manner in which it did reach 

 Spitsbergen and Greenland will be discussed more 

 fully below, and I will therefore proceed to mention 

 the other Arctic mammals. 



