TJie Indians of Cusco 25 



Ant. post, diameter Transverse Thoracic index 



African Negro IQS 269 72-5 



Navaho 216 297 72.9 



French I94 269 72.1 



The Quichua evidently have large thoraces correlated undoubt- 

 edly in part with breathing rarefied air. 



„,, , . . , / ant. post, diameter x 100 \ • . 1 11 



Ihe thoracic nidexf ^^ — r-,. )m the male shows 



\ lateral diam. / 



an average of 73.8, extremes of 84.9 and 62.4, and a variation 



range of 22.5. In the female the average is 72.3, the extremes 



84.6 and 57.5. the range of variation is 27.1. As this index is 



greater in the infant and also in the ape. our results do not 



support, so far as the Quichua are concerned, the assumption 



that the female thorax is more infantile than that of the male. 



Ears. 



The left ear was measured by sharp-pointed calipers. The 

 height represents the distance from the top of the ear to the 

 lower margin of the lobe. The breadth represents the distance 

 from the front of the helix to the posterior margin of the ear 

 at right angles to the height. The index determined from these 

 measurements represents the physiognomic and not the true or 

 morphologic index. The average ear height for the male Quichua 

 is 6.2 mm., the greatest y.^, the least 5.1, with a range of variation 

 of 2.6. The average breadth is 3.8, with 4.5 for the greatest 

 and 3.0 for the least, with a range of variation of 1.5. 



The average physiognomic index is 61. i, with 76.8 as the 

 greatest and 50.7 as the least, with a range of variation of 26.1. 



In the female the average ear height is 59, with extremes of 

 69 and 51, and a variation range of 18. The average breadth is 

 35, with extremes of 44 and 30, and a variation range of 14. 

 The physiognomic index averages 59.7, with extremes of 72.4 

 and 50. and a range of variation of 22.4. 



The ear of the female is therefore smaller than that of the male 

 in both length and breadth and has a less range of variation. 

 The index is also slightly smaller than in the male but the range 

 of variation is greater in the male. There were no observations 

 on anomalies of ear conformation. 



The following table shows the classification of the Quichua 

 based on the ear index and that a larger percentage of the 

 females belong to the hypermicrotic and microtic groups : — 



