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 '^. 



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 Delboeuf, 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 ckarly 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 ^." I think this shows entire forgetfulness 



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

 * Life and Letters, vol. iii. p. i6i. 



