Chapter XIII 



HUMAX IXHERITAXCE 



A LARGE number of malformations in man have been 

 shown to be inherited. In the medical literature there 

 are hundreds of family pedigrees in which one or an- 

 other defect appears in successive generations, espe- 

 ciallv when the stock has been rather closely inbred, 

 or where the defect is a dominant one. The few books 

 in which these cases of human inheritance have been 

 collected may give the impression that our knowl- 

 edge of man's heredity is mainly concerned with the 

 transmission of his defects. The eugenic programme 

 or recommendations with which these treatises usu- 

 ally wind uj) may give the impression that our chief 

 concern with human inheritance relates to the elimi- 

 nation of the defective materials (cacogenics) that 

 have become incorporated in the s^^ecies, rather than 

 with the discovery of superlative human materials, 

 their preservation and perpetuation (eugenics) . All 

 this calls for comment. 



General Statement 



In extenuation of the depressing effect of such 

 literature it may be said that malformations are util- 

 ized for genetic work not because of their intrinsic 

 interest — although to the pathologist they are in 

 themselves important — ^but because, as in other 



