The _Arctic Region_ comprises the _tundras_ of the Arctic littoral beyond the northern limit of forests, which last closely follows the coast-line with bends towards the north in the river valleys (70 deg. N. lat. in Finland, on the Arctic Circle about Archangel, 68 deg. N. on the Urals, 71 deg. on West Siberia). The shortness of summer, the deficiency of drainage and the thickness of the layer of soil which is frozen through in winter are the elements which go to the making of the characteristic features of the _tundras_. Their flora is far nearer those of northern Siberia and North America than that of central Europe. Mosses and lichens cover them, as also the birch, the dwarf willow, and a variety of shrubs; but where the soil is drier, and humus has been able to accumulate, a variety of herbaceous flowering plants, some of which are familiar also in western Europe, make their appearance. The _Forest Region_ of the Russian botanists occupies the greater part of the country, from the Arctic _tundras_ to the Steppes, and it maintains over this immense surface a remarkable uniformity of character. Viewed as a whole, the flora of the forest region must be regarded as European-Siberian; and though certain species disappear towards the east, while new ones make their appearance, it maintains, on the whole, the same characters throughout from Poland to Kamchatka. Thus the beech, a characteristic tree of western Europe, is unable to face the continental climate of Russia, and does not penetrate beyond Poland and the south-western provinces, reappearing again in the Crimea. The silver fir does not extend over Russia, and the oak does not cross the Urals. On the other hand, several Asiatic species (Siberian pine, larch, cedar) grow freely in the north-east, while several shrubs and herbaceous plants, originally from the Asiatic Steppes, have spread into the south-east. But all these do not greatly alter the general character of the vegetation. The _Region of the Steppes_, which covers all Southern Russia, may be subdivided into two zones--an intermediate zone and that of the Steppes proper. The Ante-Steppe of the preceding region and the intermediate zone of the Steppes include those tracts where the West-European climate struggles with the Asiatic, and where a struggle is being carried on between the forest and the Steppe.