INFLUENCE OF ENVIRONMENT 345 



character has been at all modified by its most 

 intimate association with the other. 



A striking instance of the purely temporary 

 effect of the environment and of the long per- 

 sistence of hereditary constitution amidst new 

 environmental conditions, which have greatly 

 changed the appearance of the developed or- 

 ganism, is found in the case of alpine plants. 

 Niigeli says that such plants, which have pre- 

 served the characters of high mountain plants 

 since the ice age, lose these characters perfectly 

 during their first summer in the lowlands. 



If acquired characters were really inherited 

 we should expect to find many positive evi- 

 dences of this instead of a few sporadic and 

 doubtful cases. In particular why do we not 

 find in plant or animal grafting that the in- 

 fluence of the stock changes the hereditary po- 

 tencies of the graft? Why do we not find 

 that transplanted ovaries show the influence of 



Above, young black female; In the middle, mature white fe- 

 male; below, mature white male. The white female's ovary 

 was removed and in its place was put the ovary from the 

 black female. The white female (with "black" ovary) was 

 then bred to the white male. (From Castle.) 



