The Wallace-Darwin Correspondence 



much. The Rajah has sent me some of his pigeons and 

 fowls and cats^ skins from the interior of Borneo and from 

 Singapore. Can you tell me positively that black jaguars 

 or leopards are believed generally or always to pair with 

 black ? I do not think colour of offspring good evidence. 

 Is the case of parrots fed on fat of fish turning colour men- 

 tioned in your Travels ? I remember a case of parrots with 

 (I think) poison from some toad put into hollow whence 

 primaries had been removed. 



One of the subjects on which I have been experimenting, 

 and which cost me much trouble, is the means of distri- 

 bution of all organic beings found on oceanic islands; 

 and any facts on this subject w^ould be most gratefully 

 received. 



Land-molluscs are a great perplexity to me. This is a 

 very dull letter, but I am a good deal out of health, and 

 am writing this, not from my home, as dated, but from a 

 water-cure establishment. 



With most sincere good wishes for your success in every 

 way, I remain, my dear Sir, yours sincerely, 



Ch. Darwin. 



Letter II 



C. Darwin to A. R. Wallace 



Down J Bromley y Kent. December 22, 1857. 



My dear Sir,— I thank you for your letter of Sept. 

 27th. I am extremely glad to hear that you are attending 

 to distribution in accordance with theoretical ideas. I am 

 a firm believer that without speculation there is no good 

 and original observation. Few travellers have attended to 

 such points as you are now at work on; and indeed the 

 whole subject of distribution of animals is dreadfully be- 

 hind that of plants. You say that you have been somewhat 



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