Page:Popular Science Monthly Volume 83.djvu/15

Rh is the "pronounced gorilla-like drooping of the temporal region, due to the extreme narrowing of its posterior part, which causes a deep excavation of its under surface." This feeble development of that portion of the brain which is known to control the power of articulate speech is most significant. To Professor Smith the association of a simian jaw with a cranium more distinctly human is not surprising. The evolution of the human brain from the simian type involves a tripling of the superficial area of the cerebral cortex; and "this expansion was not like the mere growth of a muscle with exercise, but the gradual building-up of the most complex mechanism in existence. The growth of the brain preceded the refinement of the features and the somatic characters in general." The Piltdown skull with its primitive brain and simian lower jaw, but with a frontal profile suggesting the modern rather than the Neandertal type, tends to prove that in the lower Quaternary the differentiation among Hominidæ had already progressed much farther than has been generally supposed; and that we shall have to go a long way back in the past to find the parting of the ways between the ancestor of man and that of his nearest of kin among the apes. The capacity of some of the male skulls of the Neandertal type is unusually large, but the brain still lacks the superior organization that characterizes the modern human brain. The Neandertal race seems to have disappeared rather suddenly at the close of the Mousterian epoch. Art-loving Aurignacian man was of a different type both physically and mentally.

Cultural remains, although much more abundant, are confined wholly to durable materials such as stone, bone, horn, and ivory. Pottery and metals are durable, but the fact that they do not occur is very good negative evidence that they were unknown. We are justified in assuming that wood, bark, roots, plant stems, skins, etc., were used, but not one trace of these has been preserved. It is also fairly safe to assume that fire-making was a very early invention of man, for unmistakable traces of it are found as far back as Mousterian times (and have been reported by one author in the Acheulian and Chellean).

The hearth suggests a roof and these the family and possibly the tribe. At Torralba, Province of Soria, Spain, the Marquis of Cerralbo has recently uncovered a large camp site, which has yielded an association of rude eolithic and Chellean industry with the remains of a very old fauna: Elephas antiquus (and possibly also the Pliocene elephant), Rhinoceros etruscus, Equus stenonis, and a large and small deer. Some sort of tribal organization would naturally develop under such conditions.

Man very early sought shelter under overhanging rocks and in caverns, but these are limited geographically while man's range was practically unlimited. La Quina (Charente) was in Mousterian times a magnificent