Page:Smithsonian Report (1898).djvu/413

Rh the breccia bed, in a word, marks the transition from steppe to forest conditions. Obviously the climate was gradually improving, the forests continuing to increase at the expense of the earlier steppe flora.

In the gray relic bed that succeeds we lose all trace of the characteristic steppe fauna. The most abundant remains are those of red deer, roe deer, horse, and ox, and with these are associated relics of a number of other forms, such as badger, wild-cat, hare, urus, goat, and sheep. The steppe fauna had now obviously become replaced by a forest fauna. Paleolithic man—the reindeer hunter of the tundras and steppes—had also vanished, and his Neolithic successor now occupied the rock shelter of the Schweizersbild. The gray relic bed and the overlying humus bed tell a most interesting tale, but into that I can not go. It is sufficient to note that the old reindeer hunters seem to have departed before forest conditions had been fully established. We may surmise that as the climate became warmer the reindeer gradually withdrew from the Alpine Vorland. Probably it had already become somewhat scarce during the accumulation of the breccia bed, in which, as will be remembered, traces and remains of it and its hunters become less and less common. One can hardly doubt that the emigration of the reindeer and the final exodus of Paleolithic man from north Switzerland were contemporaneous events, brought about by changing climatic conditions. We can picture to ourselves the old race of hunters, with the contemporaneous steppe fauna, gradually passing east and northeast, while the forests continued to encroach upon and overspread the fertile lands of central Europe. It is possible that Neolithic man may here and there have come into contact with his Paleolithic predecessor, but of this we have no evidence. All we certainly know is that the latter vanished from central Europe with the steppe fauna, and that when Neolithic man made his earliest appearance a forest fauna was in possession of the land.

In my preceding lecture evidence was adduced to show that tundras and steppes, with their characteristic faunas, formerly existed in central and west central Europe. We saw that for a long time the climatic conditions of these regions must have resembled those that now obtain in northern Siberia and the barren grounds of North America, where mosses and lichens form the prevailing growths, and arctic lemmings, hares, and foxes, the reindeer, and the musk ox are the common indigenous animals. All these characteristic species formerly lived in middle Europe. Eventually our tundra flora and fauna gradually disappeared and were as gradually replaced by steppe forms of life. Jerboas, pouched marmots, pika, and many others—such an assemblage as we now see in the subarctic steppes of southeast Russia and southwest Siberia—flourished throughout the regions over