1 8 Outline of Genetics 



would now be a race of cripples The feet of 



Chinese women of certain classes have for centuries 

 been mutilated into deformity by bandages without the 

 mutilation in any way becoming an inherited char- 

 acter The progressive degeneration or crippling 



of the little toe in man has been explained as the inherit- 

 ance of the cramping effect of shoes upon generations of 

 shoe-wearers; but Wiedersheim has pointed out that 

 Egyptian mummies show the , same crippling of the 

 little toe, and no ancient Egyptian could be accused of 

 wearing shoes, or of having shoe-wearing ancestors." 



Sheep and horses with docked tails, as well as dogs 

 with cropped ears, never produce young having the 

 parental deformity. Weismann's early experiments 

 with mice, later verified by other investigators, give 

 additional evidence that mutilations are not inherited. 

 He bred mice whose tails had been cut off short at birth, 

 and continued this performance through twenty-two 

 generations, with absolutely no eft'ect on tail length. 



Very little serious consideration has been given to the 

 possibility of inheritance of mutilations in plants. Cut- 

 tings for propagation are usually trimmed to prevent 

 excessive transpiration, but no one ever expects to find 

 this mutilation perpetuated, even in the plant developed 

 from the cutting, much less in the next generation devel- 

 oped from seed. In fact, since we have begun to learn 

 of the remarkable powers of regeneration possessed by 

 plants and animals, we would not expect the inheritance 

 of mutilations. 



There is one bit of work that should be mentioned in this con- 

 nection. Blaeinghem (3) claims to have procured from a single 

 injured individual a Hne of maize plants that show a varying per- 



