It is not necessary for my present purpose to enter further into the evidence of interglacial conditions. The latest northern ice-sheet was preceded by a long epoch of mild and genial conditions, during which elephants and hippopotami ranged north as far at least as Yorkshire; while middle Germany, as we know from the testimony of its interglacial deposits, enjoyed a similar delightful climate. And yet the immediately preceding glacial epoch had seen all those fertile regions covered with an ice-sheet that extended south as far as the fiftieth parallel of latitude. Now the question with which I am at present concerned is the extent of the latest general glaciation. Did the last great ice-sheet reach as far south as its predecessor? It certainly did not. Its bottom-moraine has now been mapped out and distinguished from that of the older ice-sheet, and we know that it does not extend so far south as the latter. It is entirely absent over all the region to the west of the River Elbe, from near Dresden to Hamburg and the coast of Holland.[M] So that western Germany and Holland, which were covered by ice during the epoch of greatest glaciation, were not invaded by the ice-sheet underneath which the upper boulder-clay was accumulated. This latest ice-sheet, however, overwhelmed all Mecklenburg and Mark Brandenburg, and streamed south nearly as far as Saxony; its southern margin extended east through Silesia, by Liegnitz and Breslau, into Poland and Russia. But the precise line it followed in the latter country has yet to be ascertained. We may surmise, however, that it nowhere reached so far south or east as the ice-flow of the earlier epoch. I may add that the southern termination of the latest ice-sheet is in many places marked out by heaps, mounds, and ridges of earthy sand, gravel, rolled stones, and erratics; in short, by terminal moraines. These, however, are frequently highly degraded and washed down. [M] Klockmann, _Jahrb. der k. preuss. geol. Landesanstalt für 1883_, p. 330. Of the extension of glacier-ice in the British Islands at the epoch in question I shall only say that the glaciation of Scotland was hardly, if at all, less extensive than during the climax of the Ice Age. Ireland, too, appears to have been almost as thickly mantled; but the ice-sheet that covered England and Wales did not extend so far south as that of the penultimate glacial epoch, a considerable area in East Anglia and the midland counties remaining apparently free from invasion. The Scandinavian and British ice-sheets, however, again coalesced upon the floor of the North Sea. III. _The Results of Fluvio-glacial Action in Europe._