CRANIOMETRY

the measurement of skulls, for comparison of the skulls of men with those of monkeys and other animals, or for comparison of the skulls of different races and different branches of the races of mankind. There are various methods of comparing skulls, the chief being (a) by comparison of length, breadth, and height of the skull, the standard of maximum length being taken at 100, so that 100 x breadth length is the breadth or cephalic index, and skulls are termed, according as the cephalic index is above 80, between 75 and 80, and below 75, brachycephalic, by comparison of the amount of cubic capacity of the skull cavity, the average being 85 cubic inches; (c) by comparison of the degree of the angle of projection of the jaws prominent jaws signifying a lower type, the degree being termed the gnathic index.