DARWIN. 235 



struggle for existence, or rather for life, between 

 different individuals and species. Four years later 

 he briefly set down his views, and in 1844 he allowed 

 himself to write out his progress. He had already 

 reached the main line of argument of his Origin 

 of Species, including the now familiar tripod of his 

 theory, Struggle, Variation, and Selection ; also his 

 principle of Sexual Selection, yet he attached much 

 more weight to the influence of external conditions 

 and to the inheritance of acquired habits than in 

 the Origin^ of 1859. 



At this time Darwin naturally looked into the 

 literature of the subject, and was reading Geoffroy 

 St. Hilaire. He carefully read and abstracted 

 Haldeman's arguments for and against the devel- 

 opment theory. He studied De Candolle upon geo- 

 graphical distribution, and Brown upon variation. 

 He was also fearful lest he should be classed with 

 Lamarck. He wrote to Hooker (Jan. n, 1844): 



"... I have now been, ever since my return, engaged in a 

 very presumptuous work, and I know no one individual who would 

 not say a very foolish one. I was so struck with the distribution 

 of the Galapagos organisms, etc., and with the character of the 

 American fossil mammifers, etc., that I determined to collect, 

 blindly, every sort of fact, which could bear in any way on what 

 are species. ... At last, gleams of light have come, and I am 

 almost convinced (quite contrary to the opinion that I started 

 with) that species are not (it is like confessing a murder) immuta- 

 ble. Heaven forfend me from Lamarck nonsense of a ' tendency 



1 See Life and Letters, Vol. II., p. 14. This was Huxley's observation 

 upon this essay in reply to a request for a criticism from the editor. This 

 essay should be published. 



