Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/226

170 and of the lower races, is still more marked in the Idiot and Chimpanzee. This type of skull is known as the long head, or dolichocephalic; that of the Calmuck, in which the forehead is developed, as the short head, or brachycephalic. Further, in the Negro the teeth are not set straight (orthognathous) as in the Calmuck, but the teeth of the upper jaw make an acute angle with those of the lower jaw (prognathous). The receding of the forehead and the angular arrangement of the teeth are accompanied by a receding of the lower jaw (see Figs. 201, 203, 204), and great development of jaws. In these peculiarities, the lower races resemble the apes, and differ from the higher races of mankind. The beastly and ferocious appearance of some savages and apes is principally due to this excessive development of the jaws. The large size of the canine teeth is also a striking feature in the skull of apes; but, as Prof. Haeckel observes, in comparing many human skulls, one always notices that the canine teeth project in some more than others; and Mr. Darwin aptly says, "he who rejects with scorn the belief that the shape of his own canines, and their occasional great development in other men, are due to our early progenitors having been provided with these formidable weapons, will probably reveal, by sneering, the line of his descent; for, though he no longer intends, nor has the power, to use these teeth as weapons, he will unconsciously retract his 'snarling muscles' (thus named by Sir C. Bell) so as to expose them ready for action, like a dog prepared to fight." The different size of the molar teeth, according to Buchner, is also important: in civilized men, of the three last teeth or molars the first is the largest, whereas in the Chimpanzee the last is the largest; the lower races o^ mankind are intermediate in this respect, the three molars being equally developed. Now, it is an interesting fact that, in the milk teeth, the last molar is the largest, as in the Chimpanzee, illustrating the law which we have had