274 PEOBABLE OKIGIN OF WHITE BEAR. 



short, and pressed "by hunger, ventured on the 

 ice and caught some seals. These individuals 

 would find that they could make a subsistence 

 in this way, and would take up their residence 

 on the shore, and 'gradually take to a life on 

 the ice. Polar bears in the present day are 

 often carried on the ice to Iceland, and even to 

 within swimming distance of Northern Norway, 

 so there is no impossibility in supposing that the 

 brown bears, who by my theory were the proge- 

 nitors of the present white bears, were accident- 

 ally driven over to Greenland and Spitzbergen 

 by storms or currents. Individual bears of TJ. 

 arctos are found frequently of a silvery grey 

 colour, and such bears are known in Norway 

 as " silver bears." Then it stands to reason 

 that those individuals who might happen to be 

 palest in colour would have the best chance of 

 succeeding in surprising seals, and those who 

 had most external fat would have the best 

 chance of withstanding the cold. The process 

 of natural selection would do the rest, and 

 Ursus arctos would, in the course of a few 

 thousands, or a few millions of years, be trans- 

 formed into the variety at present known as 

 JJrsus maritimus. 

 It may be urged against this that " there is 



