24 H. B. Ferris, M.D. 



Martin gives the racial variation in this index from 17.8 to 21.2 5 . 

 This index in the Quichua male is greater than that of any race 

 recorded and it is noteworthy that it is slightly greater in the 

 female than the male. Martin gives for the female a racial 

 variation from 17.7 to 25.2. 



Thorax Measurements. 



Measurements of the thorax were made on 85 males and 68 

 females, without removal of shirt or waist. The lateral and 

 antero-posterior diameters were measured at the nipple level in 

 medium expansion, with the arms abducted to a right angle. The 

 average lateral diameter in the male is 304, the extremes 354 and 

 ^67, giving a variation range of 87. The average antero-posterior 

 diameter is 224, the extremes 275 and 184, giving a variation 

 range of 91. 



In the female the average lateral diameter of the thorax is 

 283, the extremes 310 and 254, with a variation range of 56. The 

 average antero-posterior diameter is 205, the extremes are 254 

 and 164. and the range of variation 90. 



From these observations we see that the variation range is 

 distinctly greater in the male in the case of the lateral diameter 

 but nearly the same in both sexes in the antero-posterior diameter. 

 The smallest male and female lateral diameters are only different 

 by 13 millimeters in favor of the male, while the difference in the 

 greatest lateral diameters in the two sexes is 44 millimeters in 

 favor of the male. The least antero-posterior diameter is 20 

 millimeters greater in the male and the greatest diameter is larger 

 in the male by 21 millimeters. 



The seriation tables of the lateral chest measurements in the 

 male show that 72% are included in the group between 270 and 

 320 millimeters, while in the females 85% are found within these 

 limits. 



In the case of the antero-posterior diameters in the male 64.7% 

 are found between 200 and 230, while in the females only 57% 

 lie within these dimensions. 



These measurements were not made by the Expedition of 

 191 2. The racial variations in the male are seen from the fol- 

 lowing table from Martin (9) : — 



