364 TRANSMISSION 



SECTION III EVIDENCE FROM MUTILATIONS 



Mutilation is the forcible removal of a part after it has de- 

 veloped, or at least the destruction of those parts which are fully 

 endowed with the power of complete development. Unfortu- 

 nately, in this field the most absurd stories have gained credence, 

 and their popular acceptance has done much to obscure the 

 whole subject. Some one owned a cat whose tail was pinched 

 off in a door, and straightway all her kittens were tailless. A 

 few semi-traditional stories like this are made the foundation for 

 believing in the transmission of mutilations, the facts being for- 

 gotten that for generations it has been the custom to remove 

 the tails from lambs, with no sign yet of tailless sheep as a 

 result, and that circumcision has been practiced by many tribes 

 from the remotest times, and by the Jews certainly for four 

 thousand years, apparently without effect upon the natural de- 

 velopment of parts. Certainly, if any effect has been produced, 

 it is not evident, and is so small as to be classed among negli- 

 gible quantities, falling entirely outside the field of practical 

 results. 



The tail, being a portion of the vertebral column, might be 

 expected to long resist all influences toward its suppression ; 

 but the prepuce is an unimportant and recent structural addi- 

 tion, yet still it lingers, despite persistent and systematic 

 removal by force. 



The question lies deeper than the surface. A mutilation, like 

 any other difference, in order to be transmitted, must first 

 effect the germ plasm, which is the only material carried over. 

 If Darwin's theory of gemmules were true, then it might be con- 

 ceivable that a defective part would no longer produce its share 

 of the germ plasm, and that it would certainly disappear from 

 the race, and that at once. The fact that persistently mutilated 

 parts do not disappear is good proof not only that mutilations 

 are not transmitted, but that the theory of gemmules is incorrect. 



For the most part, belief in the inheritance of mutilation has 

 rested, not upon experimental evidence, but upon instances in 

 which natural deformities in the offspring correspond to muti- 

 lations in the parents. Such correspondence is assumed to be 



