Let us now look more closely at the discoveries made in the various caves referred to above, and also see what advances had been made by geologists in other directions during the same period, as well as what amount of progress has been made during the last twenty years. Dr. Schmerling, the Belgian geologist and comparative anatomist, after exploring the Engis and other caves in the province of Liège, published an illustrated work, giving the results of his investigations, which were highly interesting, and contributed largely to the establishment of the theory of man’s antiquity. In these caves Schmerling found the bones of the cave-bear, hyæna, elephant, and rhinoceros, together with human bones, none of which gave any evidence of having been gnawed, from which circumstance it was inferred that these caves had not been the dwelling-places of wild beasts; and the fact that the bones were scattered about without any order having been observed in their distribution pointed to the conclusion that the caves had not been used as burying-places. Probably, therefore, these remains had been washed into the caves from time to time, and had gradually become covered with deposit, and thus protected and preserved. There were no complete skeletons found; but in the Engis cave were discovered the remains of at least three human beings, the skull of one being embedded by the side of a mammoth’s tooth, and in such a state of disintegration that it fell to pieces on being moved; while the skull of another, an adult, was buried, five feet deep, by the side of a tooth of a rhinoceros, several bones of a horse, and some reindeer bones. Besides the bones, there were also discovered some rude flint implements, a polished bone needle, and other products of man’s industry, all embedded in the same layer as the bones. It follows from these facts that man lived on the banks of the Meuse at the same time as the rhinoceros, mammoth, hyæna, and cave-bear, extinct animals of the Pleiocene and early Pleistocene era.