This view seems to be confirmed by the fact that the gravel-beds in which these remains of man and extinct animals are found lie at an elevation of from eighty to _two hundred feet above the present water-levels of the valleys_. Sir John Lubbock says: "Our second difficulty still remains--namely, the height at which the upper-level gravels stand above the [1. "Mém. Soc. d'Em. l'Abbeville," 1861, p. 475.] {p. 56} present water-line. We can not wonder that these beds have generally been attributed to violent cataclysms."[1] In America, in Britain, and in Europe, the glacial deposits made clean work of nearly all animal life. The great mammalia, too large to find shelter in caverns, were some of them utterly swept away, while others never afterward returned to those regions. In like manner palæolithic man, man of the rude and unpolished flint implements, the contemporary of the great mammalia, the mammoth, the hippopotamus, and the rhinoceros, was also stamped out, and the cave-deposits of Europe show that there was a long interval before be reappeared in those regions. The same forces, whatever they were, which "smashed" and "pounded" and "contorted" the surface of the earth, crushed man and his gigantic associates out of existence.[2] But in Siberia, where, as we have seen, some of the large mammalia were caught and entombed in ice, and preserved even to our own day, there was no "smashing" and "crushing" of the earth, and many escaped the snow-sheets, and their posterity survived in that region for long ages after the Glacial period, and are supposed only to have disappeared in quite recent times. In fact, within the last two or three years a Russian exile declared that he had seen a group of living mammoths in a wild valley in a remote portion of that wilderness. These, then, good reader, to recapitulate, are points that seem to be established: I. The Drift marked a world-convulsing catastrophe. It was a gigantic and terrible event. It was something quite out of the ordinary course of Nature's operations. II. It was sudden and overwhelming. [1. "Prehistoric Times," p. 372. 2. "The Great Ice Age," p. 466.] {p. 57} III. It fell upon land areas, much like our own in geographical conformation; a forest-covered, inhabited land; a glorious land, basking in perpetual summer, in the midst of a golden age. Let us go a step further. {p. 58} CHAPTER VIII. GREAT HEAT A PREREQUISITE.