'j^ AUTOBIOGRAPHY. 



that species were mutable productions, I could not avoid the 

 belief that man must come under the same law. Accordingly 

 I collected notes on the 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 in- 

 jurious 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 accepted 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 selec- 

 tion — a subject which had always greatly interested 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 w^hich I 

 have been able to write about in full, so as to use all the ma- 

 terials 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 in- 

 tended to give only a chapter on the subject in the ' Descent 

 of Man,' but as soon as I began to put my notes together, I 

 saw that it would require a separate treatise. 



My first child was born on December 27th, 1839, ^^^ I at 

 once commenced to make notes on the first dawm of the vari- 

 ous expressions which he exhibited, for I felt convinced, even 

 at this early period, that the most complex and fine shades of 

 expression must all have had a gradual and natural origin. 

 During the summer of the following year, 1840, I read Sir C. 



