18701882] HYATT AND COPE 339 



Cope's views on acceleration and retardation of development. Letter 252 

 I had thought that Professor Cope had preceded you ; but I 

 now well remember having formerly read with lively interest, 

 and marked, a paper by you l somewhere in my library, on 

 fossil cephalopods, with remarks on the subject. It seems 

 also that I have quite misrepresented your joint view ; this 

 has vexed me much. I confess that I have never been able 

 to grasp fully what you wish to show, and I presume that this 

 must be owing to some dulness on my part. ... As the case 

 stands, the law of acceleration and retardation seems to me to 

 be a simple [?] statement of facts ; but the statement, if fully 

 established, would no doubt be an important step in our 

 knowledge. But I had better say nothing more on the 

 subject, otherwise I shall perhaps blunder again. I assure 

 you that I regret much that I have fallen into two such grave 

 errors. 



A. Hyatt to C. Darwin. Letter 253 



Mr. Hyatt replied in a long letter, of which only a small part is here 



given. 



Cannstadt bei Stuttgart, Nov. 1872. 



The letter with which you have honoured me, bearing the 

 date of October roth, has just reached here after a voyage to 

 America and back. 



I have long had it in mind to write you upon the 

 subject of which you speak, but have been prevented by a 

 very natural feeling of distrust in the worthiness and truth of 

 the views which I had to present. 



There is certainly no occasion to apologise for not having 

 quoted my paper. The law of acceleration and retardation 

 of development was therein used to explain the appearance 

 of other phenomena, and might, as it did in nearly all cases, 

 easily escape notice. 



My relations with Prof. Cope are of the most friendly 

 character ; and although fortunate in publishing a few months 

 ahead, I consider that this gives me no right to claim any- 

 thing beyond such an amount of participation in the discovery, 



1 The paper seems to be " On the Parallelism between the Different 

 Stages of Life in the Individual and those in the Entire Group of the 

 Molluscous Order Tetrabranchiata," from the Boston Soc. Nat. Hist. 

 Mem., I., 1866-69, P- J 93- On tne back of the paper is written, " I cannot 

 avoid thinking this paper fanciful." 



