204 CHARLES DARWIN. 



written to ask Darwin's permission and advice as to 

 the inclusion of some of F. MuUer's observations in 

 his most interesting paper, " Entomological Notes 

 bearing on Evolution" (Ann. and Mag. Nat. Hist, 

 1878, 5th series, Vol. I. p. 155), which he was then 

 preparing : — 



''Sept. 14, 1877. "Down. 



"Dear Sir— I have some doubts whether Fritz Miiller 

 would like extracts from his letters being published after so 

 long an interval, — that is if the letter relates to the orig in of 

 mimicry ; for he pub lished a bout a yea r ago an excell ent 

 p aper on this subiecl. 1 bfelTeve it was iri thB Jenaische 

 Zeitschrift, but the paper is out of its proper place in my 

 library and I cannot find it. If you thought it worth while 

 to send me your copy I could then judge about the publication 

 of extracts. 



"I fear it is not likely that I shall have anything to 

 communicate to the Entomological Soc. I quite agree with 

 you that it is a great pity that our Entomologists should 

 confine themselves to describing species. 



" Dear Sir, yours faithfully, " Ch. Darwin." 



''Sei^t ^2nd [1877]. "Down. 



" My dear Sir— I am doubtful whether speculations in a 

 letter ought to be published, especially after a long interval of 

 time. Any fact which he states, I feel pretty sure he would 

 not at all object being used by anyone. — Pray do the best 

 you can. — I should grieve beyond measure to be accused of 

 a breach of confidence. — He has lately, as I mentioned, thrown 

 much light on the first stops in mimickry. 



"With respect to dimorphic Butterflies, those about which 

 I have read appear at different seasons, and have been the 

 subject of an admirable essay by Prof. Weismann. It is some 

 little time since I read the essay and one subject drives 

 another out of my head, but I think he explains all such cases 

 by the direct inherited effects of temperature. He tried 



