[Illustration: FIG. 71.—Painting of a bison in orange-brown, grey, black, and white, the outline partly engraved, from the roof of the cave of Altamira, near Santander, in the north of Spain, upon which many others as well as wild-boar, horses, and deer are depicted. The original is about two and a half feet long. These drawings were executed by the Reindeer Men in the period of the Upper or Post-Glacial Pleistocene.] Yet, on account of the nearness to our own times of the events which took place in the Pleistocene period, geologists and prehistorians have studied its details with minute care, and have accumulated an immense array of facts and specimens by digging and carefully collecting in Western and Central Europe. They have divided up this Pleistocene period and the deposits in river-valley and cave which have occurred within its limits into three great consecutive ages. These are distinguished from one another by the distinctive wild animals which flourished in each, by the climate which is indicated, and by the progressive development of the art and workmanship of the Palæolithic men discovered in successive layers of deposit. Let me here refer the reader to the tabular statement on page 384 _bis_. These ages of the Pleistocene are:—No. 1. The Upper or Post-Glacial Pleistocene, or =Epoch of the Reindeer=. The climate was cold and dry, like that of the Russian steppes. The contents of the celebrated cave of La Madeleine, in the Dordogne, and the upper layers of deposit in a whole series of caves (including Kent’s Cavern and the Creswell Cave in England) belong to this age. This was the period in which the caves were inhabited by the artistic race “who came no one knows whence, and went no one knows whither,” accompanied by the reindeer. Before them there was no carving in the caves, or only very rough work, and we are justified in concluding that the men who inhabited the caves before this period belonged to a totally distinct and inferior race. The “Reindeer Men” must have developed their art by gradual steps before they arrived in the caves of Western Europe—where we do not know. At the end of this period the climate became much milder, and the red deer of our own day took the place of the reindeer, during a long transition in which the “Reindeer Men” and their art disappeared, and the pastoral, land-tilling, stone-building, pottery-making communities of the Neolithic Age came into existence, showing no trace of the art of their predecessors. The mammoth and rhinoceros, bison, and aurochs, and, in fact, all the commoner animals of an earlier period were present nearly all through the Reindeer period (they disappear in the late “transition period” of the red deer, called “Azilian”), and were known to the “Reindeer Men,” but great herds of reindeer and of horses occupied the grassy lands in this age, which were not abundant previously. These herds probably were to some extent protected by the men, whilst the