90 AUTOBIOGRAPHY. 



remember when in Good Success Bay, in Tierra del 

 Fuego, thinking (and, I believe, that I wrote home to 

 the effect) that I could not employ my life better than 

 in adding a little to Natural Science. This I have done 

 to the best of my abilities, and critics may say what 

 they like, but they cannot destroy this conviction. 



During the two last months of 1859 I was fully 

 occupied in preparing a second edition of the ' Origin/ 

 and by an enormous correspondence. On January ist, 

 1860, I began arranging my notes for my work on the 

 1 Variation of Animals and Plants under Domestica- 

 tion ; ' but it was not published until the beginning of 

 1868 ; the delay having been caused partly by frequent 

 illnesses, one of which lasted seven months, and partly 

 by being tempted to publish on other subjects which 

 at the time interested me more. 



On May I5th, 1862, my little book on the 'Fertili- 

 sation of Orchids,' which cost me ten months' work, 

 was published : most of the facts had been slowly 

 accumulated during several previous years. During 

 the summer of 1839, and, I believe, during the pre- 

 vious summer, I was led to attend to the cross-fertili- 

 sation of flowers by the aid of insects, from having 

 come to the conclusion in my speculations on the 

 origin of species, that crossing played an important 

 part in keeping specific forms constant. I attended 

 to the subject more or less during every subsequent 

 summer ; and my interest in it was greatly enhanced 

 by having procured and read in November 1841, 

 through the advice of Robert Brown, a copy of C. K. 

 Sprengel's wonderful book, ' Das entdeckte Geheimniss 



