NATURAL SELECTION SINCE DARWIN 65 



question is: do they become diversified through a 

 bitter struggle between individuals, through a rigor- 

 ous selection? 



Are we not justified in thinking, on the contrary, 

 that it is favourable conditions and a relatively easy 

 life, which create and preserve new variations? This 

 opinion is shared by several authors. Kropotkin, 

 speaking of the bleak regions of Northern Asia, 

 points out that there is little life there, and that after 

 a protracted dearth, all animals, the half -wild horses 

 and cattle of Transbaikalia, squirrels, etc., are so 

 weakened by privation that competition between them 

 could not result in any progressive evolution of the 

 species. 



The perusal of certain vital statistics tends to 

 prove the same thing. Unfavourable conditions not »/ 

 only eliminate the weak but jeopardise the health of 

 the survivors ; they therefore serve no useful end. In 

 an essay on the infantile death rate 8 Koeppe dem- 

 onstrates that in years of rigorous selection, when 

 on account of inclement weather or epidemics many 

 children die, a weaker generation survives whose death 

 rate is higher in the following years. 



Among the naturalists who have adopted this point 

 of view we must mention two who not only started 

 from entirely different premises but who devoted 

 themselves to the study of absolutely different sub- 



8 Miinchener Medizinische Woch.ensch.rift. Vol. II, p. 1547. 



