92 WORK ON 'MAN.' [l86/. 



" I am glad you were at the ' Messiah,' it is the one thing 

 that I should like to hear again, but I dare say I should find 

 my soul too dried up to appreciate it as in old days ; and 

 then I should feel very flat, for it is a horrid bore to feel as I 

 constantly do, that I am a withered leaf for every subject 

 except Science. It sometimes makes me hate Science, though 

 God knows I ought to be thankful for such a perennial 

 interest, which makes me forget for some hours every day my 

 accursed stomach." 



The work on Man was interrupted by illness in the early 

 summer of 1868, and he left home on July 16th for Fresh- 

 water, in the Isle of Wight, where he remained with his 

 family until August 21st. Here he made the acquaintance 

 of Mrs. Cameron. She received the whole family with 

 open-hearted kindness and hospitality, and my father always 

 retained a warm feeling of friendship for her. She made 

 an excellent photograph of him, which was published with 

 the inscription written by him : " I like this photograph 

 very much better than any other which has been taken 

 of me." Further interruption occurred in the autumn, so 

 that continuous work on the ' Descent of Man ' did not 

 begin until 1869. The following letters give some idea of 

 the earlier work in 1867 : ] 



C. Darwin to A. R. Wallace. 



Down, February 22, [1867 ?] 



My DEAR WALLACE, — I am hard at work on sexual selec- 

 tion, and am driven half mad by the number of collateral 

 points which require investigation, such as the relative 

 number of the two sexes, and especially on polygamy. 

 Can you aid me with respect to birds which have strongly 

 marked secondary sexual characters, such as birds of 



