Constitutional Types 211 



Among the yellow-browns all three types are found in con- 

 siderable proportions. Among the whites there are mostly 

 the medium type and the hypermorphs or slender forms, 

 with very few of the dwarf type. Among the blacks there 

 is a larger proportion of the hypomorphs or infantile type, 

 than among other races, and very few hypermorphs if any, 

 in " pure " stocks. 



Moreover, the proportions of these various types seem 

 to be undergoing a change, quite aside from the effects of 

 inter-racial mating. When large numbers of measurements 

 are brought together the curve of distribution is found to be 

 skewed in the direction of the more slender type of build. 



Constitutional Types 



Recent intensive studies of hospital patients in this coun- 

 try and in Germany show a tendency for certain types of 

 diseases to be associated with certain types of body form. 

 For example, individuals of fleshy build are more likely than 

 slender types to suffer from hardening of the arteries, dia- 

 betes, kidney disease and apoplexy; whereas the slender type 

 is in general more subject to tuberculosis, pneumonia and 

 nervous disorders. The study of family histories for the pur- 

 pose of discovering hereditary traits would indicate that 

 slenderness, as against the fleshy build, corresponds to a re- 

 cessive factor in heredity, notwithstanding the probabilities 

 that the actual development of the individual is influenced 

 through the action of the endocrine glands. In general, 

 slender parents will be found to have only slender children, 

 whereas fleshy parents may have both slender and fleshy 

 children since either or both of the individuals may come 

 of mixed parental types. ^ 



^ In the language of the student of heredity, a recessive character 

 in the offspring of a mixed mating is concealed by the corresponding 

 dominant (see page 232) . That is, all the offspring resemble the dominant 

 parent with respect to the character in question. In subsequent genera- 

 tions of hybrid parentage, the two alternative traits become separated out 



