NATURAL SELECTION SINCE DARWIN 59 



reaction of the organism through the use or disuse 

 of organs seemed to lose their importance. 



According to Darwin, natural selection preserves t^ 

 and fosters characters of direct adaptation and 

 fortuitous individual characters. According to the 

 Neo-Darwinians it acts only upon the latter char- 

 acters. Neo-Darwinians were the more willing to 

 leave the direct action of the environment in the 

 background as they held that its effects were tran- 

 sitory and did not outlast the limits of one genera- 

 tion. 



"V^e isma nn, the founder and main representative 

 of that school, reached through his theory of on- 

 togenesis and heredity - the conclusion that charac- 

 ters acquired in the course of the individual's life are 

 not transmissible, and he thereby divested those char- 

 acters of all importance as far as the future of the 

 species is concerned. Natural selection of fortuitous 

 innate variations remained the only cause of all those 

 transformations. The very significant title of one 

 of Iiis books, "The All-sufficiencv of Natural Selec- 

 tion" 3 reveals the exclusive point of view from which 

 he considers all biological phenomena. To natural se- 

 lection he attributes them all, with sometimes the 

 help of a theoretical argumentation in which we de- 



2 See Chapter IX and X. 



3 Die Allmacht der Nattirztichtung. Eine Erwiederung an Herbert 

 Spencer, 1893. 



