Among the elephant remains from St. Acheul, in M. Garnier's collection, Dr. Falconer recognised a molar of the Elephas antiquus, fig. 19, the same species which has been already mentioned as having been found in the lower-level gravels of St. Roch. This species, therefore, endured while important changes took place in the geographical condition of the valley of the Somme. Assuming the lower-level gravel to be the newer, it follows that the Elephas antiquus and the hippopotamus of St. Roch continued to flourish long after the introduction of the mammoth, a well characterized tooth of which, as I before stated, was found at St. Acheul at the time of my visit in 1860.
As flint hatchets and knives have been discovered in the alluvial deposits both at high and low levels, we may safely affirm that man was as old an inhabitant of this region as were any of the fossil quadrupeds above enumerated, a conclusion which is independent of any difference of opinion as to the relative age of the higher and lower gravels.
The disappearance of many large pachyderms and beasts of prey from Europe has often been attributed to the intervention of man, and no doubt he played his part in hastening the era of their extinction; but there is good reason for suspecting that other causes cooperated to the same end. No naturalist would for a moment suppose that the extermination of the Cyrena fluminalis throughout the whole of Europe—a species which coexisted with our race in the valley of the Somme, and which was very abundant in the waters of the Thames at the time when the elephant, rhinoceros, and hippopotamus flourished on its banks—was accelerated by human agency. The same modification in climate and other conditions of existence which affected this aquatic mollusk, may have mainly contributed to the gradual dying out of many of the large mammalia.
We have already seen that the peat of the valley of the
