( 165 ) 



CHAPTER IX. 



THE FOUNDATIONS OF THE ' OBIGIN OF SPECIES.' 



To give an account of the development of the chief work of my 

 father's life — the Origin of Species, it will be necessary to return 

 to an earlier date, and to weave into the story letters and 

 other material, purposely omitted from the chapters dealing 

 with the voyage and with his life at Down. 



To be able to estimate the greatness of the work, we must 

 know something of the state of knowledge on the species 

 question at the time when the germs of the Darwinian theory 

 were forming in my father's mind. 



For the brief sketch which I can here insert, I am largely 

 indebted to vol. ii. chapter v. of the Life and Letters — 

 a discussion on the Beception of the Origin of Species which 

 Mr. Huxley was good enough to write for me, also to the 

 masterly obituary essay on my father, which the same writer 

 contributed to the Proceedings of the Eoyal Society.* 

 Mr. Huxley has well saidf : 



" To any one who studies the signs of the times, the emer- 

 gence of the philosophy of Evolution, in the attitude of claimant 

 to the throne of the world of thought, from the limbo of hated 

 and, as many hoped, forgotten things, is the most portentous 

 event of the nineteenth century." 



In the autobiographical chapter, my father has given an 

 account of his share in this great work : the present chapter 

 does little more than expand that story. 



Two questions naturally occur to one : (1) — When and how 

 did Darwin become convinced that species are mutable ? How 

 (that is to say) did he begin to believe in evolution. And 

 (2) — When and how did he conceive the manner in which 

 species are modified ; when did he begin to believe in Natural 

 Selection ? 



The first question is the more difficult of the two to answer. 

 He has said in the Autobiography (p. 39) that certain facts 

 observed by him in South America seemed to be explicable 



♦ Vol. xliv. No. 269. 



t Life and Letters, vol. ii. p. 180. 



