666 TRAVEL IN EUROPE AND AMERICA. [1877, 



TO G. FEBDEKICK WRIGHT. 



Cambridge, April 6, 1877. 



Deak Me. Wright, — What can I ever have said 

 or written which President Fairchild takes to mean 

 that I have the preposterous idea that " changes of 

 environment take place in distinct and definite lines " ! 

 He may well ask if " this is not contrary to all evi- 

 dence." Even the conception that variation takes 

 place in definite, or at least not in indefinite, lines 

 is an idea which is rather thrown out as tenable, and 

 as inferable from a good many facts, than as anything 

 to swear by. I think so, yet, I am sorry to say, it is 

 no part of Darwinism, pure and simple. 



Now, in my turn, what does President F. mean by 

 his " mere fact " " species exist " ? That seems to 

 me no fact at all, but an inference. Individuals exist ; 

 species are inferred from the relations the individuals 

 are observed to sustain to each other. That species 

 are distinct, in the sense of none blending, is what 

 working naturalists would like to have somebody 

 settle for them in many a troublesome case. That 

 they always have been as much so as they are now is 

 the question under consideration. . . . 



May 24. 



. . . Now we can't go to see you, sorry to say. The 

 reason is, that I am working against time. Hooker 

 is coming over, and we are going in summer to the 

 Rocky Mountains together, according to an old prom- 

 ise of mine. To do it I ought to complete the print- 

 ing of the part of my " Flora " which I am upon, 

 else I shall suffer in various ways, and there is great 

 danger that I fail. 



. . . Do you notice — I know it will please you — 



