Machiganga Indians of the San Miguel Valley 77 



and 98.0, and the variation range 5.6. The Machiganga male, 

 with an average stature of 155.9, has an average module index 

 of 97.3, while the female, with average height of 143.9. has an 

 average module index of 102.8. The average for the female is 

 higher than for the male, as was true also of the Quichua, 

 chiefly because of the shorter stature of the female. This index 

 for the North American Indian 5 is given at 95.1 (Hrdlicka). 

 As was true for the Quichua, so also in the case of the Machi- 

 ganga the taller individual has a larger head absolutely but not 

 relatively. 



Cranial Capacity and Brain Weight. 



If we use the Lee-Pearson formula for determining the cranial 

 capacity in the living male (.000337 (l-ii) (b-ii) (h-ii) + 

 406.01) we obtain 1304.2 cc. as the average capacity for the 

 Machiganga. 



For the female (.000400 (l-ii) (b-ii) (h-ii) -f- 206.6) the 

 average cranial capacity is 1 192.2. 



Multiplying the cranial capacity in cubic centimeters by .87 

 (Manouvrier) we obtain for the male brain weight 1134.6 grams 

 and for the female 1037.2 grams. 



The Machiganga, then, belong to the microcephalic group 

 (-1350 cc). 



If the brain weight be estimated for the male from the stature 

 in centimeters (stature x 7) we obtain for the male 1091.3 grams 



and for the female (stature x 7 x — j 974.90 grams. 



Using Gladstone's method of estimating the brain weight, 

 which holds true between 20 and 46 years of age 



. , . \LxBxH (auricular) in centimeters \ 

 weight m grams = j ^^ j 



we obtain for the Machiganga male 1 197.2 grams and for the 

 female 11 12.7 grams. 



No records of actual brain weight or body weight for the 

 Machiganga are known to the writer. The various methods of 

 determining the brain weight in the living, while they give some- 

 what diiTering results, all show that the female brain is less in 

 weight than the male brain. The Machiganga brain is smaller 

 than that of the negro (1245) and North American Indian 

 (1265) or Quichua (1250.5). 



