453 THE UNFINISHED BOOK. [1857. 



craters on Albemarle Island, one of the Galapagos. In New- 

 Zealand urge on them to look out for erratic boulders and 

 marks of old glaciers. 



Urge the use of the dredge in the Tropics ; how little or 

 nothing we know of the limit of life downward in the hot 

 seas ? 



My present work leads me to perceive how much the 

 domestic animals have been neglected in out of the way 

 countries. 



The Revillagigedo Island off Mexico, I believe, has never 

 been trodden by foot of naturalist. 



If the expedition sticks to such places as Rio, Cape of 

 Good Hope, Ceylon and Australia, Szc, it will not do much. 



Ever yours most truly, 



C. Darwin. 



[The following passage occurs in a letter to Mr. Fox, Feb- 

 ruary 22, 1857, and has reference to the book on Evolution 

 on which he was still at work. The remainder of the letter 

 is made up in details of no interest : 



" I am got most deeply interested in my subject ; though 

 I wish I could set less value on the bauble fame, either present 

 or posthumous, than I do, but not I think, to any extreme 

 degree : yet, if I know myself, I would work just as hard, 

 though with less gusto, if I knew that my book would be pub- 

 lished for ever anonymously."] 



C. Darwin to A. R. Wallace. 



Moor Park, May 1st, 1857. 



My dear Sir, — I am much obliged for your letter of 

 October loth, from Celebes, received a few days ago ; in a 

 laborious undertaking, sympathy is a valuable and real en- 

 couragement. By your letter and even still more by your 



