ITis with races of men as with individuals, the progressive growth of youth soon reaches its limit and maturity of power. While it brings greater strength, it has not the buoyancy of early years, so the manner of life becomes fixed, and onward progress stops. They can then only hope to hold on the even tenor of their way, happy if increasing years do not bring again their childhood state. The Neolithic people entered Europe early in the youth of the race which spread their civilization over the globe, but the race to which they belonged appear to have reached their zenith of development long ages ago, since which time, whatever higher culture they have reached has been a gift to them by other people. Their energies became exhausted, and for a long series of years Europe was filled by the camps, lake villages and fortified places of Neolithic times. As to the absolute length of time during which they inhabited Europe, we have no data to determine. Relatively, their sojourn, however long, was but a short time compared to the duration of the old Stone Age. It presents no such evidence of lapse of ages as can be observed in the older deposits, yet we may be sure that it was for no inconsiderable period. The Paleolithic Age was apparently terminated in Europe by the cold of the last glacial epoch. No such natural course put an end to the Neolithic Age, but as the strong have an advantage over the weak, the young over the old, so does a race young, undeveloped, or in the early maturity of its powers, have an advantage over the older and more fixed civilization with which it comes in contact. To understand the causes which introduced into Europe the Bronze Age, we must refer to the Aryan race and to Asia. We have in the preceding chapter briefly mentioned the Aryan race. They have so much to do with the higher culture of the Metallic Ages, that it seems not out of place to refer once more to their origin. The evidence goes to show that the ancient Aryans inhabited some portion of South-western Asia. As a race or family, they appear to have been one of the latest developed. Yet a record of their progress is a record of civilization.