28 HEREDITY AND EUGENICS 



* 



height " or length of thigh, is only 24 per cent.*^ 

 Knee height includes height of ankle, which is con- 

 sidered an independent variable. The correlation 

 between supra-pubic and sub-pubic portions of 

 stature is found to be 30 per cent., and striking differ- 

 ences in the relative lengths of these portions of the 

 bod}' occur in different races of man. Thus Eskimo, 

 Mongoloids, and some American Indian tribes have 

 a relativel}^ long trunk and short legs, while the 

 Australian aborigines and some negro groups have a 

 short trunk and long legs. Of the supra-pubic 

 region, the supra-sternal or head and neck, and sub- 

 sternal or trunk portion, are independent variables 

 as regards length, with a correlation between them 

 of onh' 9 per cent. A defect in these data is, however, 

 the use of " sitting height " as a measurement, and 

 the deduction of certain elements of the stature from 

 that. 



Thus, while inherited general growth factors, such 

 as differences in the amount of secretion of various 

 glands, are concerned in determining the adult stature 

 as a whole, other factors are believed to control inde- 

 pendently the length of the various segments which 

 go to make up stature. Hence, according to this view, 

 an individual ma}" be tall because of the presence 

 of general growth factors, or because he happens to 

 have inherited length in each segment of his stature. 

 If this is true, then, of the four segments that combine 

 to form the total stature, any individual may be 

 long in some and short in others. It is commonly 

 stated that certain families have predominantly 

 long trunks and short legs, while others may have 

 short, stocky trunks combined with long or short 



* The calculation of the length of different segments of the 

 body by this indirect method introduces sources of error, as Castle 

 points out, which, at any rate, weaken Davenport's conclusions 

 regarding the inheritance of stature. 



