As these Lake-Dwellings not only belong to the last of the neolithic, but extend beyond, they naturally have a place in the close of this period. M. Troyon says the dwellings of this period came suddenly to an "end by the irruption of a people provided with bronze implements. The lake-dwellings were burned by these new-comers, and the primitive inhabitants were slaughtered or driven back into remote places. This catastrophe affects chiefly the settlements of East Switzerland, which entirely disappeared, and also a number of those on the shore of the western lakes. Some few settlements, however--namely, those of the so-called transition period--are said not to have been destroyed by the new people till after the inhabitants had begun to make use of bronze implements."[71] Dr. Keller takes exception to these views. He says there is no sudden leap from one class of civilization to another, and that the metals came gradually into use. The lake-dwellings were not burned down by the irruption of a foreign people; for at Niederwyl, and several settlements of the Unter-See, no traces of fire have been observed. The fact that but a very few human skeletons have been found in the whole settlements, contradicts the supposition of a battle having taken place between the aborigines and the supposed conquerors, and of the destruction of the former by the latter.[72] Lake-dwellings belonging to this age and the bronze, have been found in Bavaria, Northern Italy, Mecklenburg, Pomerania, France, England, Scotland, and Ireland. Herodotus says that the Pæonians lived this way in Lake Prasias (Thrace), and Lubbock says that the fishermen of Lake Prasias still inhabit wooden huts built over the water. The town of Tcherkask in Russia, is constructed over the river Don, and Venice itself is but a lacustrine city.[73]