Again, it is noticeable that, while the passage from the Neolithic age into the succeeding bronze age was gradual, and, indeed, that the use of stone implements and, in some parts, weapons, was contemporaneous with that of bronze in other places, no evidence exists of a transition from Palæolithic into Neolithic times. On the contrary, the examination of bone deposits, such as those of Kent's Cave and Victoria Cave in England, and numerous others in Belgium and France, attest "beyond doubt that a considerable period must have supervened after the departure of Palæolithic man and before the arrival of his Neolithic successor." The discovery of remains of Palæolithic man and animals in river deposits in England and on the Continent, often at considerable elevations[80] above the existing valley bottoms, and in Löss, and the identification of the Pleistocene or Quaternary period with Preglacial and Glacial times, offer a means of estimating what that lapse of time must have been.[81] Skeletons or portions of the skeletons of human beings, of admitted Palæolithic age, have been found in caverns in the vicinity of Liege in Belgium, by Schmerling, and probably the same date may be assigned those from the Neanderthal Cave near Düsseldorf. A complete skeleton, of tall stature, of probable but not unquestioned Palæolithic age, has also been discovered in the Cave of Mentone on the Riviera. These positive remains yield us further inferences than can be drawn from the mere discovery of implements or fragmentary bones associated with remains of extinct animals. The Mentone man, according to M. Rivière, had a rather long but large head, a high and well-made forehead, and the very large facial angle of 85°. In the Liege man the cranium was high and short, and of good Caucasian type; "a fair average human skull," according to Huxley. Other remains, such as the jaw-bone from the cave of the Naulette in Belgium, and the Neanderthal skeleton, show marks of inferiority; but even in the latter, which was the lowest in grade, the cranial capacity is seventy-five cubic inches or "nearly on a level with the mean between the two human extremes." We may, therefore, sum up by saying that evidences have been accumulated of the existence of man, and intelligent man, from a period which even the most conservative among geologists are unable to place at less than thirty thousand years; while most of them are convinced both of his existence from at least later Pliocene times, and of the long duration of ages which has necessarily elapsed since his appearance--a duration to be numbered, not by tens, but by hundreds of thousands of years. [Illustration: FIG. 21.--ENGRAVING BY PALÆOLITHIC MAN ON REINDEER ANTLER.] CHAPTER IV. THE DELUGE NOT A MYTH.