86 NO STRUGGLE NO SELECTION 



form, selecting carefully their individuals, and main- 

 taining carefully the process of isolation. 



In forming and maintaining his breeds, man is only 

 taking advantage of Nature's law of inheritance, and 

 of its immutable and universal principles of action. 

 For Nature to produce similar results to man's artificial 

 selection, she would require, like man, to select her 

 individuals so that the similarly varied should mate 

 only with the similarly varied, and to isolate them from 

 generation to generation, so as to prevent intercrossing. 



Let us even assume, for argument's sake, Darwin's 

 contention that in the war of Nature those individuals 

 who survive are selected individuals from their having 

 been possessed of advantageous variations. These 

 advantageous variations are of so many different kinds, 

 that, of one hundred survivors in the struggle for 

 existence, we cannot suppose that more than four could 

 be mated as possessing the same variations. The 

 question then arises : How, in the free arena of a 

 natural habitat, could Nature isolate the similarly 

 varied four per cent, from the other individuals of 

 the species ? 



To evade the difficulty arising out of this question, 

 Darwin says some extraordinary things, among which 

 I may particularise the following : " Even with 

 animals which unite for each birth, and which do 

 not propagate rapidly, we must not assume that free 

 intercrossing would always eliminate the effects of Natural 

 Selection : for I can bring forward a considerable body 

 of facts, showing that within the same area two 



