428 THE UNFINISHED BOOK. [1856. 



unphilosophical to give a resin7ie\ without exact references, 

 of an unpublished work. But Lyell seemed to think I might 

 do this, at the suggestion of friends, and on the ground, which 

 I might state, that I had been at work for eighteen ^" years, 

 and yet could not publish for several years, and especially as 

 I could point out difficulties which seemed to me to require 

 especial investigation. Now what think you ? I should be 

 really grateful for advice. I thought of giving up a couple of 

 months and writing such a sketch, and trying to keep my 

 judgment open whether or no to publish it when completed. 

 It will be simply impossible for me to give exact references; 

 anything important I should state on the authority of the 

 author generally; and instead of giving all the facts on which 

 I ground my opinion, I could give by memory only one or 

 two. In the Preface I would state that the work could not 

 be considered strictly scientific, but a mere sketch or outline 

 of a future work in which full references, &:c., should be 

 given. Eheu, eheu, I believe I should sneer at any one else 

 doing this, and my only comfort is, that I truly never dreamed 

 of it, till Lyell suggested it, and seems deliberately to think 

 it advisable. 



I am in a peck of troubles and do pray forgive me for 

 troubling you. 



Yours affectionately, 



C. Darwin. 



C, Darwin to J. D. Hooker, 



May nth [1856]. 

 . . . Now for a more important ! subject, viz., my own self : 

 I am extremely glad you think well of a separate " Pre- 

 liminary Essay " (/. e., if anything whatever is published ; for 

 Lyell seemed rather to doubt on this head) \ ; but I cannot 



* The interval of eighteen years, from 1S37 when he began to collect 

 facts, would bring the date of this letter to 1855, not 1856, nevertheless 

 the latter seems the more probable date. 



f The meaning of the sentence in parentheses is obscure. 



