WE know very little about the first "true" men. We have never seen their pictures. In the deepest layer of clay of an ancient soil we have sometimes found pieces of their bones. These lay buried amidst the broken skeletons of other animals that have long since disappeared from the face of the earth. Anthropologists (learned scientists who devote their lives to the study of man as a member of the animal kingdom) have taken these bones and they have been able to reconstruct our earliest ancestors with a fair degree of accuracy.