hrdlk'ka] 



PITYSTOLOGTCAL AND MEDTCAT. OBSERVATIONS 



119 



Per centum relations of the tlircc principal ciplialic diameters, by stature groups 

 (Tho three iiu'asurements combined = 100) 



The mean of the three principal diameters of the head is known as 

 the cephaHc module. This indicates the size of the head and is of 

 much use as a concrete figure in the study of head growth. It is con- 

 venient further in contrasting the size of the head with the stature. 



The module and its relations to stature are given in the following 

 table and curves (pi. xix) . Of the conditions which these data reveal 

 the continuous growth of the head until full adult life, the slight 

 excess in the size of the Apache head as compared with the Pima head, 

 and of the male head as compared with that of the female, have 

 already been shown. 



The module-in-relation-to-stature figures show that the head in 

 relation to the height of the body is largest in the smallest — that is, 

 in the youngest — children, the proportion decreasing steadily with age. 

 In adult and in some of the groups of adolescent females the proportion 

 of head to stature rises and finally exceeds considerably that found 

 among adult males, a fact which shows that head growth in the young 

 women continues even after the cessation of growth in height. 



Size of the head, as expressed hij the mean diameter of the }iead, or eephalie module, by 



stature groups 



