The first race of Man (circa 550,000 B.c.) is called the
"Pithecanthropos Erectus," or Ape Man. They were powerfully built individuals, with low foreheads, prominent bony ridges above the eyes, and retreating chins. Their forearms were heavy and clumsy, their thigh-bones bent and their shin-bones short, so they must have been bow-legged and awkward in gait. This type of human being became differentiated from animals because development of the faculty of primitive speech enabled them to sustain thought and created memory.