There is much that is not yet clear about the changes of climate that have been going on in Europe and Asia during the last 10,000 years. The ice of the last glacial age receded gradually, and gave way to a long period of steppe or prairie-like conditions over the great plain of Europe. About 12,000 or 10,000 years ago, as it is reckoned now, this state of affairs was giving place to forest conditions. We have already noted how, as a consequence of these changes, the Solutrian horse hunters gave place to Magdalenian fishers and forest deer hunters; and these, again, to the Neolithic herdsmen and agriculturists. For some thousands of years the European climate seems to have been warmer than it is to-day. A great sea spread from the coast of the Balkan peninsula far into Central Asia and extended northward into Central Russia, and the shrinkage of that sea and the consequent hardening of the climate of south Russia and Central Asia was going on contemporaneously with the development of the first civilizations in the river valleys. Many facts seem to point to a more genial climate in Europe and western Asia, and still more strongly to a greater luxuriance of plant and vegetable life, 4000 to 3000 years ago, than we find to-day. There were forests then in south Russia and in the country which is now Western Turkestan, where now steppes and deserts prevail. On the other hand, between 1500 and 2000 years ago, the Aral-Caspian region was probably drier and those seas smaller than they are at the present time. We may note in this connection that Thotmes III (say, the fifteenth century B.C.), in his expedition beyond the Euphrates, hunted a herd of 120 elephants in that region. Again, an Ægean dagger from Mycenæ, dating about 2000 B.C., shows a lion-hunt in progress. The hunters carry big shields and spears, and stand in rows one behind the other. The first man spears the lion, and when the wounded beast leaps at him, drops flat under the protection of his big shield, leaving the next man to repeat his stroke, and so on, until the lion is speared to death. This method of hunting is practised by the Masai to-day, and could only have been worked out by a people in a land where lions were abundant. But abundant lions imply abundant game, and that again means abundant vegetation. About 2000 B.C. the hardening of the climate in the central parts of the Old World, to which we have already referred, which put an end to elephants and lions in Asia Minor and Greece,[178] was turning the faces of the nomadic Aryan peoples southward towards the fields and forests of the more settled and civilized nations.