lS2 EVOLUTION [Chap. Ill 



Letts 122 analogous, as far as plants arc concerned, with the modern 

 plains of La Plata, which seem to have been colonised from 

 the north, but the species have been hardly modified. 



Would you kindly answer me two or three questions if in 

 your power? When species A becomes modified in another 

 region into a well-marked form C, but is connected with it 

 by one (or more) gradational forms B inhabiting an inter- 

 mediate region ; does this form B generally exist in equal 

 numbers with A and C, or inhabit an equally large area? 

 The probability is that you cannot answer this question, 

 though one of your cases seems to bear on it. . . . 



You will, I think, be glad to hear that I now often hear of 

 naturalists accepting my views more or less fully ; but some 

 are curiously cautious in running the risk of any small odium 

 in expressing their belief. 



Letter 123 To H. W. Bates. 



Down, Avvil 4th [1861]. 



I have been unwell, so have delayed thanking you for 

 your admirable letter. I hope you will not think me pre- 

 sumptuous in saying how much I have been struck with your 

 varied knowledge, and with the decisive manner in which you 

 bring it to bear on each point, — a rare and most high quality, 

 as far as my experience goes. I earnestly hope you will find 

 time to publish largely : before the Linnean Society you 

 might bring boldly out your views on species. Have you 

 ever thought of publishing your travels, and working in them 

 the less abstruse parts of your Natural History? I believe it 

 would sell, and be a very valuable contribution to Natural 

 History. You must also have seen a good deal of the natives. 

 I know well it would be quite unreasonable to ask for any 

 further information from you ; but I will just mention that I 

 am now, and shall be for a long time, writing on domestic 

 varieties of all animals. Any facts would be useful, especially 

 any showing that savages take any care in breeding their 

 animals, or in rejecting the bad and preserving the good ; or 

 any fancies which they may have that one coloured or marked 

 dog, etc., is better than another. I have already collected 

 much on this head, but am greedy for facts. You will at once 

 sec their bearing on variation under domestication. 



Hardly anything in your letter has pleased me more than 



