Machiganga Indians of the San Miguel Valley 75 



The following" table shows the grouping of the Machiganga 

 according to ear index : — 



Index Class Machiganga ^ Machiganga $ 



( -54.9) Hypermicrotic 6.7 per cent 



(55-59.9) Microtic 33.3 per cent 26.7 per cent 



(60-64.9) Mesotic 55.6 per cent 53.3 per cent 



(65- ) Macrotic ii.i per cent 13.3 per cent 



The modulus of the ear is the mean of the two dimensions 

 ( — ^^) The average ear modulus in the Machiganga male is 



50, in the female 47.5. In the negro it is 48.4 (Hrdlicka), and 

 in the North American Indian 53 (Hrdlicka). 



The ear is believed to be larger in tall people and to increase 

 in dimensions with stature and age, the height increasing rela- 

 tively more than the breadth, so that while the modulus increases 

 with age the index decreases. An analysis of these relations 

 in the Machiganga will not be profitable on account of the few 

 individuals measured. 



Head. 



The head measurements were made on 18 males and 15 females, 

 by the methods already described for the Quichua. 



The greatest head length for the male averages 18.1, the 

 extremes are 18.8 and 17.2, and the variation range 1.6. In the 

 female the average head length is 17.3, the extremes are 18.3 

 and 16.8, and the variation range 1.5. The maximum width of 

 the head in the male averages 14.5, with extremes of 15.6 and 

 13.7, and a variation range of 19. In the female this dimension 

 averages 14. i, with extremes of 15.0 and 13.3, and a variation 

 range of 1.7. The head height (meatal-bregma) in the male 

 averages 12.8, the extremes are 13.4 and 12.0, and the variation 

 range 1.4. In the female the average height is 12.8, the extremes 

 13.0 and 12.5, and the variation range 0.5. 



It is seen that all of the dimensions of the head are smaller in 

 the female except the height while the variation range is about 

 the same except in head height where it is distinctly less in the 

 female. 



The head measurements in the Machiganga male are all smaller 

 than in the Quichua with the exception of the height, which 



