320 Darwin, and after Darwin. 



been directed to proving that such is the case, it will now, 

 I think, be sufficient to supply but one further quotation, in 

 order to show that the above " latest expression of opinion," 

 far from indicating that in his later years Darwin " inclined " 

 to Mr. Wallace's views upon this matter, is quite compatible 

 with a distinct " expression of opinion " to the contrary, in 

 a letter written less than six years before his death. 



" In my opinion tke greatest error which I have committed, 

 has been not allowing sufficient weight to the direct action of 

 the environment, i.e. food, climate, &c., independently of natural 

 selection. Modifications thus caused, which are neither of 

 advantage nor disadvantage to the modified organisms, would 

 be especially favoured, as I can now see chiefly through 

 your observations, by isolation in a small area, where only 

 a few individuals lived under nearly unifonn conditions^" 



I will now proceed to quote further passages from 

 Darwin's works, which appear to have escaped the notice of 

 Mr. Wallace, inasmuch as they admit of no doubt regarding 

 the allusions being to specific characters. 



" We may easily err in attributing importance to characters, 

 and in believing that they have been developed through natural 

 selection. We must by no means overlook the effects of the 

 definite action of changed conditions of life, — of so-called 

 spontaneous variations, which seem to depend in a quite 

 subordinate degree on the nature of the conditions, — of the 

 tendency to reversion to long-lost characters, — of the complex 

 laws of growth, such as of correlation'', compensation, of 

 pressure of one part on another, &c., and finally of sexual 

 selection, by which characters of use to one sex are often 

 gained and then transmitted more or less perfectly to the 



' Life and Letters, ■^^. iii. p. 158. 



' It must be observed that Darwin uses this word, not as Mr. Wallace 

 always uses it (viz. as if correlation can only be with regard to adaptive 

 characters), but in the wider sense that any change in one part of an 

 organism — whether or not it happens to be an adaptive change — is apt 

 to induce changes in other parts. 



