XVIII 



DARWIN AND GEOLOGY 



By J. W. Judd, C.B., LL.D., F.RS. 



In one of the very interesting conversations which I had^with 

 Charles Darwin during the last seven years of his life 1 , he asked 

 me in a very pointed manner if I were able to recall the circum- 

 stances, accidental or otherwise, which had led me to devote myself 

 to geological studies. He informed me that he was making similar 

 inquiries of other friends, and I gathered from what he said that 

 he contemplated at that time a study of the causes producing 

 scientific bias in individual minds. I have no means of knowing how 

 far this project ever assumed anything like concrete form, but certain 

 it is that Darwin himself often indulged in the processes of mental 

 introspection and analysis ; and he has thus fortunately left us — in 

 his fragments of autobiography and in his correspondence — the 

 materials from which may be reconstructed a fairly complete history 

 of his own mental development. 



There are two perfectly distinct inquiries which we have to 

 undertake in connection with the development of Darwin's ideas on 

 the subject of evolution : 



First. How, when, and under what conditions was Darwin led 

 to a conviction that species were not immutable, but were derived 

 from pre-existing forms? 



Secondly. By what lines of reasoning and research was he 

 brought to regard " natural selection " as a vera causa in the process 

 of evolution ? 



1 Mr Francis Darwin has related how his father occasionally came up from Down 

 to spend a few days with his brother Erasmus in London, and, after his brother's death, 

 with his daughter, Mrs Litchfield. On these occasions, it was his habit to arrange 

 meetings with Huxley, to talk over zoological questions, with Hooker, to discuss botanical 

 problems, and with Lyell to hold conversations on geology. After the death of Lyell, 

 Darwin, knowing my close intimacy with his friend during his later years, used to ask me 

 to meet him when he came to town, and "talk geology." The "talks" took place 

 sometimes at Jermyn Street Museum, at other times in the Royal College of Science, 

 South Kensington; but more frequently, after having lunch with him, at his brother's 

 or his daughter's house. On several occasions, however, I had the pleasure of visiting 

 him at Down. In the postscript of a letter (of April 15, 1880) arranging one of these 

 visits, he writes : " Since poor, dear Lyell's death, I rarely have the pleasure of geological 

 talk with anyone." 



n. 22 



