94 AUTOBIOGRAPHY. 



subject for my own satisfaction, and not for a long 

 time with any intention of publishing. Although in 

 the ' Origin of Species ' the derivation of any particular 

 species is never discussed, yet I thought it best, in 

 order that no honourable man should accuse me of 

 concealing my views, to add that by the work " light 

 would be thrown on the origin of man and his history." 

 It would have been useless and injurious to the success 

 of the book to have paraded, without giving any 

 evidence, my conviction with respect to his origin. 



But when I found that many naturalists fully ac- 

 cepted the doctrine of the evolution of species, it 

 seemed to me advisable to work up such notes as I 

 possessed, and to publish a special treatise on the 

 origin of man. I was the more glad to do so, as it 

 gave me an opportunity of fully discussing sexual 

 selection a subject which had always greatly inte- 

 rested me. This subject, and that of the variation of 

 our domestic productions, together with the causes 

 and laws of variation, inheritance, and the intercrossing 

 of plants, are the sole subjects which I have been able 

 to write about in full, so as to use all the materials 

 which I have collected. The ' Descent of Man ' took 

 me three years to write, but then as usual some of 

 this time was lost by ill-health, and some was consumed 

 by preparing new editions and other minor works. 

 A second and largely corrected edition of the 'Descent' 

 appeared in 1874. 



My book on the ' Expression of the Emotions in 

 Men and Animals ' was published in the autumn of 

 1872. I had intended to give only a chapter on the 



