Alfred Russel Wallace 



9 St. Mark's Crescent, N.W. January 30, 1869. 



Dear Darwin, — ^Will you tell me where are Fleeming 

 Jenkin's arguments on the importance of single varia- 

 tion ? Because I at present hold most strongly the con- 

 trary opinion, that it is the individual differences or 

 general variability of species that enables them to become 

 modified and adapted to new conditions. 



yariations or ^^ sports *' may be important in modify- 

 ing an animal in one direction, as in colour for instance, 

 but how it can possibly work in changes requiring co- 

 ordination of many parts, as in Orchids for example, I 

 cannot conceive. And as all the more important struc- 

 tural modifications of animals and plants imply much co- 

 ordination, it appears to me that the chances are millions 

 to one against individual variations ever coinciding so as 

 to render the required modification possible. However, let 

 me read first what has convinced you. 



You may tell Mrs. Darwin that I have now a daughter. 



Give my kind regards to her and all your family. — Very 

 truly yours, Alfred R. Wallace. 



Down, Bromley, Kent, S.E. February 2, 1869. 



My dear Wallace, — I must have expressed myself atro- 

 ciously ; I meant to say exactly the reverse of what you have 

 understood. F. Jenkin argued in the North British Review"- 

 against single variations ever being perpetuated, and has 

 convinced me, though not in quite so broad a manner as 

 here put. I always thought individual differences more 

 important, but I was blind and thought that single varia- 

 tions might be preserved much oftener than I now see is 

 possible or probable. I mentioned this in my former note 

 merely because I believed that you had come to similar 



1 June, 1867. 

 234 



