PROBABLE ORIGIN OF WHITE BEAR. 249 



Norway as "silver bears." Then it stands to rea- 

 son that those individuals who might happen to be 

 palest in color would have the best chance of suc- 

 ceeding in surprising seals, and those who had most 

 external fat would have the best chance of with- 

 standing 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 transformed into the variety at present 

 known as Ursus maritimus. 



It may be urged against this that "there is no 

 reason, if my theory is true, why brown bears are 

 not still occasionally taking to a Polar life, catch- 

 ing seals and turning white" (?) The answer is 

 easy ; the ground is already occupied by the varie- 

 ty of bear formed by Nature, acting through the 

 process of natural selection, for catching seals. The 

 seals are so shy that even the existing white bears 

 have difficulty in living, and a brown bear, although 

 he may eke out his means of subsistence by occasion- 

 ally still catching a seal on the shores of Siberia, 

 would have no chance of succeeding in the struggle 

 for life if he were to set off on a seal-hunting ex- 

 pedition, and to enter into competition with his 

 white congeners, who are already formed and fitted 

 by Nature, through countless generations, for that 

 particular mode of life.* 



* It will be obvious to any one that I follow Mr. Darwin in 

 these remarks ; and although the substance of this chapter was 

 written in Spitzbergen, before the "Origin of Species" was 



