1S92] Elliot, hihcritatice of Acquired Characters. *1C\ 



tions, I call natural !>election.* Some," he states, "have even 



imagined that natural selection induces variability, whereas 

 it implies only the preservation of such variations as occur, and 

 are beneficial to the being under its conditions of life" ; and he 

 farther says,t "■unless profitable variations do occur, natural selec- 

 tion can do nothing"; also, J "unless favorable variations be inher- 

 ited by some at least of the offspring nothing can be effected by 

 natural selection," and this is reiterated farther on,§ "nothing 

 can be effected unless favourable variations occur," and he goes 

 on to sayjl "what applies to one animal will apply through all 

 time to all animals — that is if they vary — for otherwise natural 

 selection can do nothing." It will thus be seen that the author 

 of this doctrine expresses himself in the most positive terms that 

 the principle does not originate variation, but on the contrary is 

 only effective when variation arising from some other cause has 

 been produced. Let us consider some of the causes which, from 

 the results, lead us to believe that they have originated variation, 

 and first among these is environment. Darwin paid little or no 

 attention to the influences of this cause, and in his letter to Moritz 

 Wagner he says : "In my opinion the greatest error I have com- 

 mitted has been not allowing suflicient weight to the direct action 

 of the environment, that is food, climate, etc., independently of 

 natural selection. Modifications thus caused, which are neither 

 of advantage or» disadvantage to the modified organism, would be 

 especially favored, as I can now see, chiefly through your obser- 

 vations, by isolation in a small area, where only a few individuals 

 live under nearly uniform conditions. When I wrote the 'Origin 

 of Species,' and for some years afterwards, I could find little evi- 

 dence of the direct action of the environment. Now there is a 

 large body of evidence."^ It is, I think, the general belief, of 

 ornithologists at all events, that a form to be successful in attain- 

 ing ! new development, must be isolated from other forms. This 

 would seem to be self-evident ; otherwise an individual that 



*Origin of Species, 3d ed. p. 84. 



flbid. p. 86. 



JIbid. p. 107. 



{Ibid. p. 114. 



||Ibid. p. iig. 



HDarwin's Life and Letters, Vol. Ill, p. 159. 



