Thus we seem shut up to the conclusion that the close of the palanthropic age was marked by great geological vicissitudes of the character of submergence, leading primarily to vast destruction of animal life, and secondarily to permanent changes both in geography and climate, under which new conditions the neanthropic age was inaugurated. How this took place we have to inquire in the sequel. In the meantime we may merely remark that since the two principal races of primitive men known to us in Europe seem to have perished, we must infer that individuals of a third race beyond the limits of Europe were destined to survive, and again to replenish the earth in the new era, and that possibly these may be represented by the solitary Truchère skull. In the case of many of the more bulky and unwieldy animals inhabiting the plains the case was different. They perished, or if any survived the submergence they were unable to multiply under the new conditions. Desperate attempts have been made in the interests of extreme uniformitarianism to discredit the abrupt change from palæocosmic to neocosmic men. It has been supposed that the latter replaced the former as conquerors--a most unlikely theory, when their relative powers are considered. It has been conjectured that as the cold decreased the old races of men followed the reindeer to the north and became Arctic peoples. But why did they not rather attack the new animals, which in that case must have come in from the south? It has even been supposed that the Esquimaux may be their descendants; but they are quite different in physical characters, and have no nearer resemblance in their arts than other rude peoples. In opposition to all this we have not only the remarkable change in the races of men and in their animal associates, but when we know that the whole geographical features of our continents have changed since the palanthropic age, and that not only are our continents reduced in size since the continental post-glacial period, but that there is evidence of re-elevation as well as subsidence, and this within a short period--say eight thousand years less the historic period on the one hand and the early palanthropic on the other--it seems impossible to doubt the greatness and suddenness of the physical break that divides the anthropic age into two distinct portions. All this may be held to be certainly known as geological fact, and it would be folly to overlook it in any discussions as to primitive man, or in any comparisons of the evidence afforded by his remains with that of early human history or tradition.