Page:Geological Evidences of the Antiquity of Man.djvu/390

370 from the upper layers of peat, for example, as compared to those found in the lower ones. The great number also of the Swiss lake-dwellings of the bronze age, (those already discovered amounting to about seventy,) and the large population which some of them were capable of containing, afford indication of a considerable lapse of time, as does the thickness of the stratum of mud in which, in some of the lakes, the works of art are entombed. The unequal antiquity, also, of the settlements, is occasionally attested by the different degrees of decay which the wooden stakes or piles have undergone, some of them projecting more above the mud than others, while all the piles of the antecedent age of stone have rotted away quite down to the level of the mud, such part of them only as was originally driven into the bed of the lake having escaped decomposition.

Among the monuments of the stone period, which immediately preceded that of bronze, the polished hatchets called celts are abundant, and were in very general use in Europe before metallic tools were introduced. We learn, from the Danish peat and shell-mounds, and from the older Swiss lake-settlements, that the first inhabitants were hunters, who fed almost entirely on game, but their food in after ages consisted more and more of tamed animals, and, still later, a more complete change to a pastoral state took place, accompanied, as population increased, by the cultivation of some cereals (p. 21).

Both the shells and quadrupeds, belonging to the ages of stone and bronze, consist exclusively of species now living in Europe, the fauna being the same as that which flourished in Gaul at the time when it was conquered by Julius Cæsar, even the Bos primigenius, the only animal of which the wild type is lost, being still represented, according to Cuvier,