ORIGIN OF SPECIES 209 



premises, which vitiated the early treatment of the 

 problem of heredity and variation and the en- 

 tire problem of the evolution of species as a whole. 

 The most critical students of the problems that 

 are involved in the doctrine of descent, are extreme- 

 ly dissatisfied with the alleged evidence on which it 

 rests. 



As Bateson states: "The advance has been from 

 many sides. Something has come from the work of 

 systematists, something from cultural experiments, 

 something from the direct study of variation as it 

 appears in nature, but progress is especially due to 

 experimental investigation of heredity. From all 

 these lines of inquiry we get the same answer; that 

 what the naturalists of fifty years ago regarded as 

 variation is not one phenomenon but many, and that 

 what they would have adduced as evidence against 

 the definiteness of species may not in fact be capable 

 of this construction at all."^° 



Concerning the arguments employed in treating 

 of the problem, Bateson writes: 



"A vast assemblage of miscellaneous facts 

 could formerly be adduced as seemingly com- 

 parable illustrations of the phenomenon 'varia- 

 tion.' Time has shown this mass of evidence to 

 be capable of analysis. The transformation of 



*" Problems of Genetics, 15. 



