x] OF EVOLUTION 123 



months, while he was absent from home, and unable 

 therefore to refer to his abundant notes Darwin 

 speaks of it, therefore, as ' done from memory. ' 



The two sketches, as Mr Francis Darwin points 

 out, were each divided into two distinct parts, though 

 this arrangement is not adopted in the Origin of 

 Species, as finally published. Charles Darwin on many 

 occasions spoke of having adopted the Principles of 

 Geology as his model. That work as we have seen 

 consisted of a first portion (eventually expanded from 

 one to two volumes), in which the general principles 

 were enunciated and illustrated, and a second portion 

 (forming the third volume), in which those principles 

 were applied to deciphering the history of the globe 

 in the past. I think that Darwin's original intention 

 was to follow a similar plan ; the first part of his 

 work dealing with the evidences derived from the 

 study of variation, crossing, the struggle for exist- 

 ence, etc., and the second to the proofs that natural 

 selection had really operated as illustrated by the 

 geological record, by the facts of geographical dis- 

 tribution, and by many curious phenomena exhibited 

 by plants and animals. Although this plan was 

 eventually abandoned no doubt wisely when the 

 Origin came to be written, we cannot but recognise 

 in it another illustration of the great influence 

 exercised by Lyell and his works on Darwin an in- 

 fluence the latter was always so ready to acknowledge. 



