EVOLUTION AS A NATURAL PROCESS 115 



as the cumulative result of the sun's din^ct efTects. 

 ^jamarck laid greater stress u|)()n (he indirccf nr f nnr- 

 Lonal variations due to the factors of us(> and disus(>. 

 a ^d he also assumed as self-cvidci ij t hat such cfYcc ts~ 

 w„ere transmissible Uti ''''r'(|iiin>(l ^'li uractcrs. " Tlii.s 

 expression has a technical significance, for it refers to 

 variations that are added during individual Vifo to 

 the whole group of hereditary (luahtics that make any 

 animal a particular kind of organism. If ovohition 

 takes place at all, any new kind of organism originating 

 from a different parental type must truly acquire its 

 new characteristics, but few indeed of the variations 

 appearing during the hfetime of an animal owe their 

 origin to the functional and environmental infhicnces, 

 whose effects only deserve the name of ''acquired 

 characters" in the special biological sense. 



In sharp contrast to Lamarckianism, so called, — al- 

 though it did not originate in the mind of the noted 

 man of science whose name it bears, — is the doctrine 

 of natural selection, first proposed in its full form l»y 

 Charles Darwin. This doctrine presents a wholly 

 natural description of the method by which organisms 

 evolve, putting all of the emphasis upon the congenital 

 causes of variation, although the reality of other kinds 

 of change is not questioned. But the contrast between 

 Darwinism and the oilier descriptions of secondary 

 factors can best be made after a somewhat detailed 

 discussion of the former, which has gained the adhe- 

 rence of the majority of the naturalists of ttvday. 

 However, we must not pass on ^vithout pointing out tliat 

 however much the explanations given by various men 

 of science may differ, they all agree in expressly rt^cog- 



