There is one character, however, by which the primates in general are distinguished from the lower mammals, whilst in the human species it is far more strongly marked than in other primates; but in the criminal this character is often so little developed as hardly to reach the degree characteristic of prehistoric human remains. The character in question is the greater development of the cranium (dependent upon the more powerful development of the cerebral hemispheres) in association with a lesser development of the jaws and their appendages. In this way the direct cerebrogenous characters originate; and with these are associated yet other characters, evidently in part mechanically dependent on the cerebrogenous characters, but in part arising from these in a different way. To this category belongs prognathism—the condition in which the upper jaw protrudes markedly in front of the base of the skull, so that when the face is viewed in profile, the region of the incisor teeth appears very prominent. The skulls of the lower races of mankind are prognathous, and still more prognathous are the skulls of the anthropoid apes. Directly associated with prognathism is another characteristic of the criminal type—namely, the forehead which “recedes” markedly as it rises; and associated with the receding forehead is a marked projection of the “superciliary ridges.” It is well known that the two earliest known human skulls—that of the Neanderthal and that of Spy—both exhibit to a high degree the two characters last mentioned. If we compare with these the drawing in Lombroso’s “Archivio di psichiatria” (vol. ii., 1882) of the skull of Gasparone (the brigand celebrated under the name of “Fra Diavolo”), we cannot fail to recognize a striking example of atavism. One of the most remarkable of these characters is the middle occipital fossa, first described by Lombroso, whose dependence upon the formation of the cerebellum is still open to dispute. In any case it is a well-marked primatoid character, for it is present in all the higher primates, with the exception of the gorilla, the chimpanzee, and the orang-utan. The middle occipital fossa was found to be present in 4·1 per cent. of the skulls provided with “students’ sets” that were examined (but it must be remembered that such skulls always include a certain proportion of the skulls of criminals). In prehistoric skulls the character was present in 14·3 per cent.; in ancient Peruvian skulls in 15 per cent.; in Australian blacks in 28 per cent.; in all the criminal skulls examined it was present in 20 per cent. The significance of such a fact as this cannot be gainsaid; and it is not surprising that its discovery by Lombroso, the pupil of Panizza, made a profound impression, more especially in view of the fact that he was then about to bring to a close his comparison of the European with the melanodermic races.