In the chimpanzee we observe the very prominent bony ridges above the eyes, like those in the Trinil and Neanderthal races of men. The prognathous or protruding tooth rows and receding chin suggest those in the Heidelberg, Piltdown, and Neanderthal races. When the chimpanzee is walking (Fig. 18) the arms reach down below the level of the knees, whereas in the higher races of man they reach only half-way down the thighs. Thus, the fore limb, although much shorter than that of the gibbon, is relatively longer than that of any human race, recent or ancient. We observe also in the walking chimpanzee (Fig. 18) that the upper part of the leg, the thigh-bone, or femur, is relatively long, while the lower part, the shin-bone, or tibia, is relatively short. Indeed, both in the arm and in the leg the upper bones are relatively long and the lower bones are relatively short. These proportions, which are inheritances of arboreal life, are in very marked contrast to those observed in the arms and legs of the Neanderthal race of men, in which the limbs are of the terrestrial or walking type. [Illustration: ANCESTRAL TREE OF THE ANTHROPOID APES AND OF MAN EXISTING GIBBON. MAN CHIMPANZEE. GORILLA. ORANG. APES AND Asia. (_Homo sapiens_). Africa. Africa. Asia. MAN. | Asia, Europe. | | | | | | | | _Crô-Magnon_ and | / / | other races | / / | | / / | More primitive | / / | species, human | / / | and prehuman. | / / GLACIAL OR | | | / Macaque PLEISTOCENE | | | | of AGE. | _Neanderthal race._ | | | Europe. | | | | | | _Piltdown race._ | | | | | | | | | | _Heidelberg race._ | | | | | | | | | PLIOCENE | | | | | AGE. | _Trinil race_ | | | | | (_Pithecanthropus_). | | | | Primitive Ancestral anthro- | Macaques Gibbon of poids of Asia. | of Asia Europe | | / and (_Pliohylobates_). | / / Europe.