But ancient man had lost sight of this fact and continued to use the wooden plow of his earliest ancestors and continued to believe in the same gods that had been worshipped ten thousand years before and taught his children to do likewise. Instead of going forward he stood still and this was fatal. For a new and more energetic race appeared upon the horizon and the ancient world was doomed. We call these new people the Indo-Europeans. They were white men like you and me, and they spoke a language which was the common ancestor of all our European languages with the exception of Hungarian, Finnish and the Basque of Northern Spain. When we first hear of them they had for many centuries made their home along the banks of the Caspian Sea. But one day (for reasons which are totally unknown to us) they packed their belongings on the backs of the horses which they had trained and they gathered their cows and dogs and goats and began to wander in search of distant happiness and food. Some of them moved into the mountains of central Asia and for a long time they lived amidst the peaks of the plateau of Iran, whence they are called the Iranians or Aryans. Others slowly followed the setting sun and took possession of the vast plains of western Europe. They were almost as uncivilized as those prehistoric men who made their appearance within the first pages of this book. But they were a hardy race and good fighters and without difficulty they seem to have occupied the hunting grounds and the pastures of the men of the stone age. They were as yet quite ignorant but thanks to a happy Fate they were curious. The wisdom of the ancient world, which was carried to them by the traders of the Mediterranean, they very soon made their own. But the age-old learning of Egypt and Babylonia and Chaldea they merely used as a stepping-stone to something higher and better. For "tradition," as such, meant nothing to them and they considered that the Universe was theirs to explore and to exploit as they saw fit and that it was their duty to submit all experience to the acid test of human intelligence. [Illustration: A COLONY.] Soon therefore they passed beyond those boundaries which the ancient world had accepted as impassable barriers--a sort of spiritual Mountains of the Moon. Then they turned against their former masters and within a short time a new and vigorous civilization replaced the out-worn structure of the ancient Asiatic world. But of these Indo-Europeans and their adventures I give you a detailed account in "The Story of Mankind," which tells you about the Greeks and the Romans and all the other races in the world. A FEW DATES CONNECTED WITH THE PEOPLE OF THE ANCIENT WORLD I can not give you any positive dates connected with Prehistoric Man. The early Europeans who appear in the first chapters of this book began their career about fifty thousand years ago. THE EGYPTIANS