246 LIFE OF DARWIN 



friends descriptive of what he had seen and done. He 

 likewise forwarded considerable collections of specimens 

 gathered by him at various places. His scientific 

 activity was therefore well known at home to his ac- 

 quaintances, and even to a wider circle, for some of his 

 letters to Henslow were privately printed and circulated 

 among the members of the Cambridge Philosophical 

 Society. It would have been difficult for any even 

 of his most intimate friends to offer a plausible con- 

 jecture as to the line of inquiry in natural science that 

 he would ultimately select as the one along which he 

 more particularly desired to advance. An onlooker 

 might have naturally believed that the ardent young 

 observer would choose geology, and end by becoming 

 one of the foremost leaders in that department of 

 science. In his Journal of Researches, and in the 

 letters from the Beagle now published, it is remarkable 

 how much he shows the fascination that geology 

 exercised upon him. He had thoroughly thrown off 

 the incubus of Wernerianism. From Lyell's book and 

 Sedgwick's personal influence he had discovered how 

 absorbingly interesting is the history of the earth. 

 Writing to his friend, W. D. Fox, from Lima, in 

 the summer of 1835, ne expresses his pleasure in hear- 

 ing that his correspondent had some intention of 

 studying geology ; which, he says, offers ' so much 

 larger a field of thought than the other branches of 

 natural history ' ; and, moreover, c is a capital science 

 to begin, as it requires nothing but a little reading, 

 thinking and hammering.' While the whole of his 

 Journal shows on every page how keen were his powers 

 of observation, and how constantly he was on the 



