Page:Popular Science Monthly Volume 50.djvu/598

578 between 75 and 80 are characterized as mesocephalic. The two skulls in our illustrations, viewed from above, show how marked the differences in these proportions may be. In very rare instances the index may run in individuals as low as 62, and it has been observed as high as 103—that is to say, the head being broader than it is long. In our study, which is not of individuals, but of racial groups, the limits of variation are of course much



less. We shall seldom find heads in any considerable numbers exceeding the limits roughly indicated by the two crania in our illustrations.

A factor which is of great assistance in the rapid identification of racial types is the correlation between the proportions of the head and the form of the face. In the majority of cases, particularly in Europe, a relatively broad head is accompanied by a rounded face, in which the breadth back of the cheek bones is