Dark eyes.{1. Black.
{2. Brown.
Light eyes.{1. Light brown (hazel).
{2. Gray.
{3. Blue.

The eye must be examined at some little distance so as to catch the total effect.

Next in the order of prominence is

The Hair.—Indeed, Haeckel and others have based upon its character the main divisions of mankind. That of some races is straight, of others more or less curled. This difference depends upon the shape of the hairs in cross-section. The more closely they assimilate true cylinders, the straighter they hang; while the flatter they are, the more they approach the appearance of wool. (Fig. 5.) The variation of the two diameters (transverse and longitudinal) is from 25:100 to 90:100. The straightest is found among the Malayans and Mongolians; the wooliest among the Hottentots, Papuas and African negroes. The white race is intermediate, with curly or wavy hair. It is noteworthy that all woolly-haired peoples have also long, narrow heads and protruding jaws.

Fig. 5.—Cross Sections of Hairs.

The amount of hair on the face and body is also a point of some moment. As a rule, the American and Mongolian peoples have little, the Europeans and Australians abundance. Crossing of races seems to strengthen its growth, and the Ainos of the Japanese Archipelago, a mixed people, are probably the hairiest of the species. The strongest growth on the head is seen among the Cafusos of Brazil, a hybrid of the Indian and negro.

The Muscular Structure.—The development of the muscular structure offers notable differences in the various races. The blacks, both in Africa and elsewhere, have the gastrocnemii or calf muscles of the leg very slightly developed; while in both them and the Mongolians the facial muscles have their fibres more closely interwoven than the whites, thus preventing an equal mobility of facial expression.

The anomalies of the muscular structure seem about as frequent in one race as in another. The most of them are regressive, imitating the muscles of the apes, monkeys, and lower mammals. Indeed, a learned anatomist has said that the abnormal anatomy of the muscles supplies all the gaps which separate man from the higher apes, as all the simian characteristics reappear from time to time in his structure.[13]

Certain motions or positions, such as I may call “muscular habits,” are characteristic of extensive groups of tribes. The method of resting is one such. The Japanese squats on his hams, the Australian stands on one leg, supporting himself by a spear or pole, and so on. The methods of arrow-release have been profitably studied by Professor E. S. Morse. He finds them so characteristic that he classifies them ethnographically, with reference to savagery and civilization, and locality. The three most important are the primary, the Mediterranean, and the Mongolian releases. The first is that of many savage tribes, the second was practiced principally by the white race, the last by the Mongolians and their neighbors. (Figs. 6, 7, 8.) The last two are the most effective, and thus gave superiority in combat.