Recapitulation of Results arrived at in the earlier Chapters. Ages of Stone and Bronze. Danish Peat and Kitchen-Middens. Swiss Lake-Dwellings. Local Changes in Vegetation and in the wild and domesticated Animals and in Physical Geography coeval with the Age of Bronze and the later Stone Period. Estimates of the positive Date of some Deposits of the later Stone Period. Ancient Division of the Age of Stone of St. Acheul and Aurignac. Migrations of Man in that Period from the Continent to England in Post-Glacial Times. Slow Rate of Progress in barbarous Ages. Doctrine of the superior Intelligence and Endowments of the original Stock of Mankind considered. Opinions of the Greeks and Romans, and their Coincidence with those of the Modern Progressionist. The ages of stone and bronze, so called by archaeologists, were spoken of in the earlier chapters of this work. That of bronze has been traced back to times anterior to the Roman occupation of Helvetia, Gaul, and other countries north of the Alps. When weapons of that mixed metal were in use, a somewhat uniform civilisation seems to have prevailed over a wide extent of central and northern Europe, and the long duration of such a state of things in Denmark and Switzerland is shown by the gradual improvement which took place in the useful and ornamental arts. Such progress is attested by the increasing variety of the forms, and the more perfect finish and tasteful decoration of the tools and utensils obtained from the more modern deposits of the bronze age, those 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 (about seventy villages having been already discovered), 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.* (* Troyon, "Habitations lacustres" Lausanne 1860.)