of gigantic and of diminutive size. But in passing from the Pliocene into the Quaternary period, they all, or almost all, disappeared, and were superseded by the _Elephas Primigenius_, or mammoth, which had put in a first appearance in the latest Pliocene, and became the principal representative of the genus _Elephas_ in Europe and Northern Asia down to comparatively recent times. This succession is confirmed by that of the rhinoceros, of which several species were contemporary with the _Elephas Meridionalis_, while the _Rhinoceros tichorinus_, or woolly rhinoceros, who is the inseparable companion of the mammoth, appeared and disappeared with him. In these matters, those who are not themselves specialists must rely on authority, and when we find Lyell, Geikie, and Prestwich coinciding with all modern French, German, Italian, and Belgian geologists, in considering _Elephas Meridionalis_ as one of the characteristic Upper Pliocene fauna, we can have no hesitation in adopting their conclusion. In this case the section of St. Prest, near Chartres, affords a first absolutely secure foothold in tracing our way backwards towards human origins beyond the Quaternary. The sands and gravels of a river which ran on the bed rock without any underlying glacial _débris_ are here exposed. It had no relation to the existing river Eure, the bed of which it crosses at an angle, and it must have run before that river had begun to excavate its valley, and when the drainage of the country was quite different. The sands contain an extraordinary number of bones of the _Elephas Meridionalis_, associated with old species of rhinoceros, and other Pliocene species. Lyell, who visited the spot, had no hesitation in calling it a Pliocene river. In fact it never would have been disputed if the question of man's antiquity had not been involved in it, for in these sands and gravels have been found numerous specimens of cut bones of the _Elephas Meridionalis_, together with the flint knives which made the cuts, and other stone implements, rude but still unmistakably of the usual palæolithic type. The subjoined plate will enable the reader to compare the arrow-head, which is the commonest type found at St. Prest, with a comparatively recent arrow-head from the Yorkshire wolds, and see how impossible it is to concede human agency to the post-glacial and deny it to the Pliocene specimen. [Illustration: PLIOCENE. ARROW-HEAD--ST. PREST. (Hamy, _Palæontologie Humaine_.) POST-GLACIAL. ARROW-HEAD--YORKSHIRE WOLDS. (Evans, _Stone Implements_.)]