According to Rutot, the neolithic is wholly superficial, never being found in situ in the brick earth. Whether the latter is entirely barren of industry remains to be determined. As it was deposited by the last flood waters of the Quaternary, to find middle or upper Magdalenian industry near its base should create no surprise. At the other end of the series the paleolithic stops short of the lower Quaternary, the industry of the latter being purely eolithic.
Respecting technology, the various paleolithic types of implements are for the most part so familiar to students of the prehistoric that with one or two exceptions I have deemed it unnecessary to figure them (figs. 4 and 5). They admit of separation into two more or less distinct groups. The older, practically confined to the diluvial deposits, is represented by the Strépyan, Chellean, and Acheulian. The generalized type, common to all three horizons, is the almond-shaped implement chipped on both sides. The younger group, common both to the upper series of diluvial deposits and the caverns, includes the Mousterian, Aurignacian, Solutréan and Magclalenian horizons. Lithologically, it is composed largely of flint flakes that are chipped on one side only. The group is characterized also by the appearance of bone implements and the beginnings of the arts of sculpture, engraving, and painting. In this as well as the older group there is everywhere orderly development marked either by refinement of preexisting forms or the appearance of new ones. The result is that a given combination of cultural phenomena has its definite stratigraphic position. The two kinds of evidence are therefore in harmony.
Of the three elements of control, the least thoroughly mastered is paleontology. Some forms appear, disappear, and reappear. Some, again, persist in certain latitudes much longer than in others. Elephas antiquus, for example, and Rhinoceros merckii existed in France from the beginning of the Quaternary to the lower Acheulian epoch, having retreated from Belgium with the coming on of the Riss glaciation. Farther south, at Grimaldi, we find them contemporary with Mousterian man. Their successors, Elephas primigenius and Rhinoceros tichorhinus, appeared in Belgium as early as the Strépyan and persisted almost until the end of the Quaternary, as their remains have been found in the lower Flandrian deposits (ergeron).
The researches of Commont prove that at the beginning of the paleolithic there were two adjacent contemporary zoological provinces, (1) a northern, including England (for Great Britain and Ireland were then a part of the mainland), Belgium, and northern Ger- many with the fauna of the mammoth, and (2) a southern, including the greater part of the Paris basin and the valley of the Somme, where the fauna of Elephas antiquus still persisted. The fauna of the mammoth overran France in the Acheulian epoch, i.e., about the time that Elephas antiquus retreated toward the south. If these facts
