twelve towns and four hundred villages. Probably many a century may have elapsed between the occupation by the lake-dwellers and their removal to villages on dry land. For how long a time these lake-dwellings were inhabited we probably can hardly decide. In general they are believed to have existed from one to two thousand years; consequently, since the settlement of the first Swiss lake-dwelling at least from three to four thousand years have elapsed. But if our cave-dwellers had actually been contemporary with the lake-dwellers, they would certainly have held mutual relations with them; for the Kesslerloch was distant from Stein, the nearest lake-dwelling, only about a walk of two good hours, and the cave-dwellers would certainly have learnt a very great deal from the more advanced lake-dwellers. But the antiquities found in our cave do not give the least trace or indication of the lake-dwellings. The total absence of corn, of pottery, of bored stones, and of stone celts, and also of domestic animals, and, I may add, the entirely altered fauna, are very certain evidences that the age when men lived in caves is to be sought for far beyond that of the lake-dwellings. I have already stated that these changes of fauna arise from changes of climatic relations. But climatic changes do not occur in short periods; thousands of years are required for them. The period during which our cave was inhabited cannot certainly be accurately fixed; but, at all events, many centuries must have passed before a relic-bed nearly three feet in thickness could have been formed. Now although by these reasonings as to the inhabitants of the Kesslerloch we cannot make out any determinate number of years chronologically, yet they enable us to arrive at the conclusion that many thousands of years must have elapsed since the first settlement of man in the cave of Thayngen. One fact already mentioned confirms this idea, and that is, that the lowest part of the relic-bed is at least four feet under the present level of the valley. But as the flat of the valley was formed by deposits of gravel and sand, brought down to it, and as at one time in fact it was under water, the Kesslerloch must have been inhabited before this alluvial action. Very probably this alluvial deposit in the valley arose from the Lake of Radolphzell, which at one time had its outlet by Gottmadingen and Thayngen to Schaffhausen. Doubtless this outlet did not exist while the cave was inhabited, although the lake was no great distance off. I explain this fact by assuming that at that time the lake was probably held back from running in that direction by the rubbish-heaps in
