HEREDITY. 399 



kinds of characters are inheritable, and what are not 

 inheritable. 



It has been insisted by Weismann and others that 

 characters which are newly acquired by an organism 

 are not inherited, whether they be products of normal 

 or abnormal conditions. In support of this view, he 

 points to the early isolation in embryonic life of the 

 reproductive cells from the remainder of the organism, 

 and their continued isolation during later life, so that 

 they are protected from the stimulating influences 

 which affect the remainder of the body. He also 

 points to the permanence of this isolation of the germ 

 plasma from generation to generation, which insures 

 only the transmission of those characters which it 

 contains, as distinct from those which are found in 

 the remaining cells of the organism, which constitute 

 the body or soma. The characters which are inher- 

 ited, and which are present at birth are termed con- 

 genital, while those which appear in the body under 

 the influence of external stimuli are termed acquired. 

 The theory of Weismann then is, that the acquired 

 characters are not inherited. 



Besides the fact that sporadic injuries and mutila- 

 tions of the soma are not inherited, there have been 

 cited various cases of the non-inheritance of mutila- 

 tions which have been often repeated and for long 

 periods of time. Thus the rupture of the hymen in 

 human females has not been followed by its abolition. 

 The practice of circumcision by the Jews has not re- 

 sulted in the disappearance from that race of the por- 

 tion of the body thus artificially removed. The con- 

 tinued cutting of the hair of men of many races has 

 not made it less abundant. The practice of distorting 

 the feet of a class of their women by the Chinese has 



