But of these mammals I need not tell you much for you know them well. They surround you on all sides. They are your daily companions in the streets and in your home, and you can see your less familiar cousins behind the bars of the zoological garden. And now we come to the parting of the ways when man suddenly leaves the endless procession of dumbly living and dying creatures and begins to use his reason to shape the destiny of his race. One mammal in particular seemed to surpass all others in its ability to find food and shelter. It had learned to use its fore-feet for the purpose of holding its prey, and by dint of practice it had developed a hand-like claw. After innumerable attempts it had learned how to balance the whole of the body upon the hind legs. (This is a difficult act, which every child has to learn anew although the human race has been doing it for over a million years.) This creature, half ape and half monkey but superior to both, became the most successful hunter and could make a living in every clime. For greater safety, it usually moved about in groups. It learned how to make strange grunts to warn its young of approaching danger and after many hundreds of thousands of years it began to use these throaty noises for the purpose of talking. This creature, though you may hardly believe it, was your first “man-like” ancestor. OUR EARLIEST ANCESTORS 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. [Illustration: THE GROWTH OF THE HUMAN SKULL] The great-great-grandfather of the human race was a very ugly and unattractive mammal. He was quite small, much smaller than the people of today. The heat of the sun and the biting wind of the cold winter had coloured his skin a dark brown. His head and most of his body, his arms and legs too, were covered with long, coarse hair. He had very thin but strong fingers which made his hands look like those of a monkey. His forehead was low and his jaw was like the jaw of a wild animal which uses its teeth both as fork and knife. He wore no clothes. He had seen no fire except the flames of the rumbling volcanoes which filled the earth with their smoke and their lava.