EVOLUTION AS A NATURAL PROCESS 115 



as the cumulative result of the sun's direct effects. 

 Lamarck laid greater stress upon the indirect or func- 

 tional variations due to the factors of use and disuse, 

 and he also assumed as self-evident that such effects 

 were transmissible as '^acquired characters." This 

 expression has a technical significance, for it refers to 

 variations that are added during individual life to 

 the whole group of hereditary qualities that make any 

 animal a particular kind of organism. If evolution 

 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 lifetime of an animal owe their 

 origin to the functional and environmental influences, 

 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 by 

 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 other 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 to-day. 

 However, we must not pass on without pointing out that 

 however much the explanations given by various men 

 of science may differ, they all agree in expressly recog- 



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