The Polissye Plain also extends to the left bank of the Dnieper, and there imperceptibly passes over into a comparatively narrow lowland district which stretches along the main river of the Ukraine. This is the third member of the series of plains of the Ukraine—the Dnieper Plain. It extends toward the southeast as far as the region of the rapids (porohi) of the Dnieper and rises slowly toward the northeast, passing over into the Central [58]Russian Plateau. The transition takes place so imperceptibly that the difference in the nature of the country only becomes apparent at the furthest bounds of Ukrainian territory, which practically lie in the southern spurs of the Central Russian Plateau. The Dnieper Plain is quite level only along the river itself. Every year a strip of the plain, in places 10 km. wide, is flooded by the Dnieper River, wherefore it is full of old river beds and swamps, on the Desna and near Cherkassy, where the lowland, too, enters upon the right Dnieper bank, and also of sand-dunes. Near Chernihiv and Uizin the landscape is quite Polissian and the name Polissye, too, is often used here to denote the region. Toward the southeast the Polissian character begins to gradually disappear. Black earth takes the place of the sandy soil, the forest mantle becomes constantly thinner, and the flat, undulating steppe-plain, with its innumerable barrows and plate-shaped depressions of ground, where, in springtime, small steppe lakes glisten in the sunlight, increases very rapidly. The river valleys, along which the Dnieper Plain intrudes far into the Central Russian Plateau, are very wide valley slopes on the right, and flat slopes on the left side. Sand, swamps and forest terraces cover the flat valley bottoms, which are flooded every spring. At the porohs of the Dnieper the country rises much higher than at Pereyaslav or Kreminchuk, where the Dnieper Plain rises barely 50 m. above sea-level. At the porohs the landscape on both sides is that of a low rock-plateau. The picturesque rocks of the Dnieper banks, the rapids and ledges of rock in the river bed, everywhere remind us that here the Ukrainian Horst is crossed by the main stream of the Ukraine. Not until we get down to the Zaporoze (land below the rapids) do we find the genuine lowland character again—in the Pontian Steppe-plain. [59]