When once the recognition of Drift Man, founded on the authority of Lyell, was achieved, search for further relic-beds was made in England and France with success. Yet scarcely one of the newly discovered stations was to be compared to those of the Somme valley as regards purity of stratification and conditions of discovery. The relics of the “earliest Stone Age” or “Palæolithic Period,” as the period of Drift Man was called, frequently came from caves and grottos, whose primary conclusiveness Boucher had rightly doubted. Under these circumstances it was of the greatest importance that in Germany Drift Man was discovered in two places, where not only was the geological stratification just as clear as at Abbeville and Amiens, but where also the relics of Drift Man were found, not in a secondary _situs_, as they were then, but in a primary one. In addition to this the two German relic-beds may be safely assigned to the last two great divisions of the Drift Period, to the warmer Interglacial Period, and to the cold Glacial Period proper, with its Postglacial Period; and their climatic conditions were made clear from the remains of plants and animals found in them. [Illustration: Mercier A WORKER IN THE STONE AGE Making an axehead of flint, like that photographed on the opposite page. From the painting by F. Cormon. ] From the occurrence, in the deposits of the Somme, of reindeer that contain the stone implements of Drift Man, we can not, as we saw, exactly settle in what part of the Drift Era man lived there, whether in the Interglacial Period, to which numerous animal remains found there doubtless belong, or not until the “Reindeer” Period, as the last Glacial and early Postglacial Periods were called, when the reindeer was most largely distributed over France and Central Europe. One is inclined to date man’s habitation of the Somme valley back to the Interglacial Period; but it is certain that the relic-bed near Taubach is the first, and, as far as I can see, the only one hitherto, that has given sure proof of Interglacial Man in Europe. There the oldest vestiges of man in Europe were found that have yet been absolutely proved. We have not hitherto succeeded in Europe in tracing man farther back than the Interglacial Period. Relics of him are hitherto as absent in the older Drift as they are in the Tertiary. [Illustration: A WORKMAN’S TOOL IN THE STONE AGE Flint implement found in Gray’s Inn, London; now in British Museum. ]