Alfred Russel Wallace 



which I have vainly attempted to get an answer to ? — Believe 

 me yours very faithfully, Alfred E. Wallace. 



4 Chester Place, Regent's Park, N.W, March 19-24, 1868. 



My dear Wallace, — I have sent your query to Cambridge 

 to my son. He ought to answer it, for he got his place of 

 Second Wrangler chiefly by solving very difficult problems. 

 I enclose his remarks on two of your paragraphs : I should 

 like them returned some time, for I have not studied them, 

 and let me have your impression. 



I have told E. Edwards to send one of my large photo- 

 graphs to you addressed to 76^ Westbourne Grove, not to 

 be forwarded. When at home I will send my carte. 



The sterility is a most [? puzzling] problem. I can see 

 so far, but I am hardly willing to admit all your assump- 

 tions, and even if they were all admitted, the process is 

 so complex and the sterility (as you remark in your note) 

 so universal, even with species inhabiting quite distinct 

 countries (as I remarked in my chapter), together with 

 the frequency of a difference in reciprocal unions, that I 

 cannot persuade myself that it has been gained by Natural 

 Selection, any more than the difficulty of grafting distinct 

 genera and the impossibility of grafting distinct families. 

 You will allow, I suppose, that the capacity of grafting has 

 not been directly acquired through Natural Selection. 



I think that you will be pleased with the second volume 

 or part of LyelPs Principles, just out. 



In regard to sexual selection. A girl sees a handsome 

 man, and without observing whether his nose or whiskers 

 are the tenth of an inch longer or shorter than in some 

 other man, admires his appearance and says she will marry 

 him. So, I suppose, with the pea-hen; and the tail has 

 been increased in length merely by, on the whole, present- 

 ing a more gorgeous appearance. Jenner Weir, however, 



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