no Darwin, and after Darwin. 



Darwin wrote thus to Professor Weismann in 

 1872:- 



I have now read your essay with very great interest. Your 

 view of the origin of local races through " Amixia " is altogether 

 new to me, and seems to throw an important light on an obscure 

 question *. 



And in the last edition of the Variation of Animals 

 and Plants he adds the following paragraph : 



This view may throw some light on the fact that the domestic 

 animals which formerly inhabited the several districts in Great 

 Britain, and the half-wild cattle lately kept in several British 

 parks, differed slightly from one another; for these animals were 

 prevented from wandering over the whole country and inter- 

 crossing, but would have crossed freely within each district or 

 park 2 . 



Now, although I allow that Darwin never attri- 

 buted to this principle of Amixia, or Independent 

 Variability, anything like the degree of importance 

 to which, in the opinion of Delbceuf, Gulick, Giard, 

 and myself, it is entitled, the above passage appears 

 to show that, as soon as the "view" was clearly 

 'suggested" to his mind, he was so far from being 

 unfavourably disposed towards it, that he added 

 a paragraph to the last edition of his Variation for 

 the express purpose of countenancing it. Never- 

 theless, later on the matter appears to have entirely 

 escaped his memory ; for in 1878 he wrote to Semper, 

 that he did " not see at all more clearly than I did 

 before, from the numerous cases which he [Wagner] 

 has brought forward, how and why it is that a long 

 isolated form should almost always become slightly 

 modified 3 ." I think this shows entire forgetfulness 



* Life and Letters > vol. iii. p. 155. a Variation, &c., vol. ii. p. 262. 

 3 Life and Letters, vol. iii. p. 16). 



