FOOTNOTES:
[144] Bull. 62, Bur. Amer. Ethn., p. 22, Nos. 326-313.
[145] More or less danger in such cases as these lies in erroneous sexing of the skulls. Due to experience, care, and especially to the relatively numerous accompanying bones or skeletons, this danger in the present series has been reduced to the minimum.
[146] Bull. 62, Bur. Amer. Ethn., p. 23.
[147] Cat. Crania, U. S. Nat. Mus., No. 2.
MODULE AND CAPACITY
A comparison of considerable interest is also that of the cranial module or mean diameter, to the capacity of the same skulls. This comparison reveals an important sex factor.[148] Relatively to the module, the capacity is very appreciably smaller in the female than it is in the male. This is a universal condition to which, so far as known, there are occasional individual but no group exceptions. It appears very clearly in the Eskimo. In 283 western male Eskimo skulls in which we have so far measured the capacity,[149] the module averages 15.38 centimeters, the capacity 1,490 cubic centimeters; while in 382 female skulls thus far gauged the former averages 14.82 centimeters, the latter 1,337 cubic centimeters. The percentage relation of the capacity to the module, the numbers taken as a whole, is 96.8 in the males but only 90.2 in the females. This means that relatively to the external size of the skull the female Eskimo brain is 6.66 per cent smaller. Similar sex disproportion exists in other American groups as well as elsewhere. Some day when suitable data accumulate it will be of much interest to study this condition on a wider scale.