These figures seem to leave no reasonable doubt that some at least of the flints from Thenay show unmistakable signs of human handiwork, and I only hesitate to accept them as conclusive proofs of the existence of man in the Middle Miocene, because such an authority as Prestwich retains doubts of their having come from the geological horizon accepted by the most eminent modern French geologists.
MIDDLE MIOCENE IMPLEMENTS.
BORER, OR AWL. Thenay. Miocene.
(Congrès Préhistorique, Bruxelles, 1872.(Congrès Préhistorique, Bruxelles, 1872.)
KNIFE, OR SCRAPER. Thenay.
(Gaudry. Quatrefages, p. 92.)
The evidence of the authenticity of these implements from Thenay is, moreover, greatly strengthened by the discovery of other Miocene implements at Puy Courny, which have not been seriously impugned, and by the essay of Professor Prestwich, confirming the discovery of numerous flint implements in the upper level gravels of the North Downs, which could only have been deposited by streams flowing from a mountain ridge along the Anticlinal of the Weald, of which 2000 feet must have disappeared by sub-aërial denudation since these rivers flowed northwards from its flanks. How far back such a denudation may carry us is a matter of speculation. Certainly, as Prestwich admits, into the pre-glacial or very early glacial ages, and possibly into the Tertiaries, but at any rate for a time which, by whatever name we call it, must be enormous according to any standard of centuries or millenniums. And what is specially interesting in these extremely ancient implements is that, in Prestwich's words, "these plateau implements exhibit distinct characters and types such as would denote them to be the work of a more primitive and ruder race than those fabricated by palæolithic men of the valley drift times."