Darwinism from the more recent evolutionary theory, e. g., 

 of De Vries who rejects the notion that species have origi- 

 nated by the accumulation of fluctuating variations; and it 

 is quite as essential to the Darwinian theory of natural 

 selection as is the "struggle for life." It is, in fact, an in- 

 tegral element in the selection theory. 



The attitude of science towards Darwinism may, 

 therefore, be conveniently summarized in its answer to the 

 following questions: i. Is there any evidence that such 

 a struggle for life among mature forms, as Darwin postu- 

 lates, actually occurs? 



2. Can the origin of adaptive structures be explained 

 on the ground of their utility in this struggle, i. e., is it cer- 

 tain or even probable that the organism would have per- 

 ished, had it lacked the particular adaptation in its present 

 degree of perfection? On the contrary, is there not con- 

 vincing proof that many, and presumably most, adapta- 

 tions cannot be thus accounted for? 



The above questions are concerned with "the struggle 

 for life." Those which follow have to do with the problem 

 of variations. 



3. Is there any reason to believe that new species may 

 originate by the accumulation of fluctuating individual 

 variations? 



4. Does the evidence of the geological record — which, 

 as Huxley observed, is the only direct evidence that can be 

 had in the question of evolution — does this evidence tell 

 for or against the origin of existing species from earlier 

 ones by means of minute gradual modifications? 



13 



