Racial Definition—the Field of the Physical Anthropologist Physical anthropology has its difficulties and uncertainties when it tries to reach back deep into time. But the tests by which it distinguishes races seem as sound and dependable as those of any of the disciplines that deal with early man. Some of the results are certainly striking. There are problems, of course, as to the order in which the various races developed and spread throughout the Old World. In the opinion of some authorities, the Pygmy, or Negrito, came first. The Pygmy, although resembling the Negro in most respects, has in general one of the roundest heads of all mankind, while the Negro’s is pre-eminently long and narrow. Many anthropologists pick the Australoid as the second race to leave an unknown homeland and spread far abroad. The White, or Caucasoid, racial stock is divided into certain groups by one authority, and into other groups by another. Hooton puts the beginnings of the White race far back by calling the Australoid “an archaic form of modern White man.”[3] But, in spite of conflicts of opinion, the physical anthropologist has fairly firm ground to stand on. He can bring to bear on the skull or the fleshed bone of man certain tests, certain measurements, which enable him to discriminate with some accuracy between the various racial types. The most important of the measurements have to do with the shape of the head and certain of its features. The Cephalic Index—and Others A hundred years ago a Swedish scientist, Anders Retzius, set up a measurement called the cephalic index, which indicates whether a head is dolichocephalic or brachycephalic—long-headed or round-headed, narrow or broad. The width of the skull, divided by its length, and multiplied by 100, gives the cephalic index—as 15.0 cm. ÷ 17.6 cm. × 100 = 85.23. The long-headed, or dolichocephalic, skull, lies below 75; the round-headed, or brachycephalic, at or above 80. Between lies the intermediate ground of the mesocephalic. (It is rather easy to keep “dolichocephalic” and “brachycephalic” straight if you note that the longer word applies to the long-headed skulls.)