MENDEL'S DISCOVERY 191 



prehension is evident from a passage where he 

 describes an experiment or observation on cats 

 which, as it happens, gave a simple Mendelian result. 

 The Angora character (recessive) disappeared in a cross 

 with a certain common cat whose hair character is, 

 as we now know, dominant. The crossbreds were 

 mated together, and the Angora character reappeared 

 in one individual among a litter of common cats. 

 This typically Mendelian fact was thus actually 

 under Nageli's own observation, but from the dis- 

 cussion which he devotes to the occurrence it is clear 

 that Mendel's work must have wholly passed from 

 his memory, having probably been dismissed as some- 

 thing too fanciful for serious consideration." 



Mendel's theory could not be grafted on to con- 

 temporary biological opinion : the cross was too 

 wide, to borrow Butler's simile. But, grafted on to the 

 biological opinion prepared by Weismann, it flourished 

 like a green bay tree ; and its immense value was at 

 once recognised. 



To regard, now, the relation between Mendel's 

 and Weismann's work from the second-mentioned 

 point of view.* In the first place, Mendel's results 

 support Weismann's doctrine, because the only theory 

 which can as yet account for these results leaves the 

 characters of the soma or body entirely out of account 

 and relates solely to the contents of the germ cells 

 which produce the generation whose character has 

 to be explained. On no other theory but Weis- 

 mann's would an extracted green pea of the fifth 



♦ Second paragraph on p. 189. 



