98 EVOLUTION [CHAP, ti 



Letter 52 was meeting with Barne'oud's 1 paper which made me think 

 there might be truth in the doctrine. Your instance of 

 heart and brain of fish seems to me very good. It was a 

 very stupid blunder on my part not thinking of the posterior 

 part of the time of development. I shall, of course, not 

 allude to this subject, which I rather grieve about, as I 

 wished it to be true ; but, alas ! a scientific man ought to 

 have no wishes, no affections a mere heart of stone. 



There is only one point in your letter which at present I 

 cannot quite follow you in : supposing that Barne'oud's (I do 

 not say Brulle"'s) remarks were true and universal i.e., that the 

 petals which have to undergo the greatest amount of develop- 

 ment and modification begin to change the soonest from the 

 simple and common embryonic form of the petal if this 

 were a true law, then I cannot but think that it would throw 

 light on Milne Edwards' proposition that the wider apart the 

 classes of animals are, the sooner do they diverge from the 

 common embryonic plan which common embryonic [plan] 

 may be compared with the similar petals in the early bud, 

 the several petals in one flower being compared to the 

 distinct but similar embryos of the different classes. I much 

 wish that you would so far keep this in mind, that whenever 

 we meet I might hear how far you differ or concur in this. 

 I have always looked at Barneoud's and Brulle"'s proposition 

 as only in some degree analogous. 



P.S. I see in my abstract of Milne Edwards' paper, he 

 speaks of " the most perfect and important organs " as being 

 first developed, and I should have thought that this was 

 usually synonymous with the most developed or modified. 



Letter 53 To J. D. Hooker. 



The following letter is chiefly of interest as showing the amount and 

 kind of work required for Darwin's conclusions on " large genera varying," 

 which occupy no more than two or three pages in the Origin (Ed. I., 

 p. 55). Some correspondence on the subject is given in the Life and 

 Letters, II., pp. 102-5. 



1 Apparently Barneoud "On the Organ ogeny of Irregular Corollas," 

 from the Comptes rendus, 1847, as given in Annals and Mag. of Natural 

 History, 1847, p. 440. The paper chiefly deals with the fact that in their 

 earliest condition irregular flowers are regular. The view attributed to 

 Barneoud does not seem so definitely given in this paper as in a previous 

 one (Ann. Sc. Nat., Bot, Tom. VI., p. 268). 



