Page:Palæolithic Man and Terramara Settlements in Europe.djvu/63

Rh so well known, thus describes the relation of contemporary mammalia to glacial phenomena:—

In his recent Huxley Memorial Lecture (Journ. Anth. Inst., vol. xl.) the same author has categorically tabulated the successive migrations of the Pleistocene mammalia into Britain, and the fate of extinction which has befallen many of them.

The entire series of phenomena incidental to the varying phases of the glacial epoch are so complicated that it is difficult to realise the exact conditions which led to the intermingling of such different animals as are included in the lists of northern and southern faunas. On the supposition that the Ice Age was one climatic interlude, presenting a gradual extension of local glaciers until they culminated in a mer de glace, with of course a corresponding period for their retreat, as advocated by de Mortillet, the association of these different animals in Central Europe would be more readily understood. The following explanation of the problem from the standpoint of those who maintain that the Pleistocene comprised a series of successive ice ages, with warm interglacial periods, comes from the pen of Professor James Geikie:—

"In opposition to those who believed that the Palæolithic epoch was marked by strongly contrasted summers and winters, inducing great annual migrations, I maintained that the evidence betokened an alternation of cold and genial climatic conditions. The same view was subsequently set forth in my 'Prehistoric Europe,' where I have brought together the evidence derived not only from the mammalia, but from the former distribution of moluscs and plants. The facts which have since come to light all point clearly to the same conclusion, namely—that during Palæolithic times great changes of climate took place. All the