Very wide areas in northern Germany are covered with an almost continuous sheet of glacial detritus, so that it is only occasionally that the underlying rocks crop out at the surface. Striated rock-surfaces are therefore by no means so commonly exposed as in regions like the Lowlands of Scotland. They are not wanting, however, and their evidence is very striking. Thus, in the neighbourhood of Leipzig and Dresden, we find glacial striæ impressed upon certain highly-abraded and ice-worn hillocks of porphyry, the striæ being the work of ice which flowed into Saxony from the north. Similar striæ;, having a general southerly trend, occur at Rüdersdorf, near Berlin, at Gommern, near Magdeburg, at Velpke in Brunswick, at Osnabrück in Hanover, and at other places. Again, we encounter remarkable evidence of the powerful pressure exerted by the ice in the displacement and removal of huge blocks of strata. In Saxony, for example, the Tertiary strata are turned up, pushed out of place, and involved in boulder-clay to such an extent that the brown coals have often been mined for in this strange position. Witness also the extensive displacements and dislocations of the Cretaceous formation in the Danish islands of the Baltic. So great are the contortions and displacements of the Chalk in Moen, that these disturbances were formerly attributed to subterranean action. Along the north-east coast of that island, cliffs 400 feet in height exhibit the Cretaceous beds thrown upon end, twisted, bent, and even inverted, boulder-clay being squeezed into and between the disjointed and ruptured rock-masses.