r 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.

The Steppes proper are very fertile elevated plains, slightly undulated,
and intersected by numerous ravines which are dry in summer. The
undulations are scarcely apparent to the eye as it takes in a wide
prospect under a blazing sun and with a deep-blue sky overhead.
Not a tree is to be seen, the few woods and thickets being hidden
in the depressions and deep valleys of the rivers. On the thick
sheet of black earth by which the Steppe is covered a luxuriant
vegetation develops in spring; after the old grass has been burned
a bright green covers immense stretches, but this rapidly disappears
under the burning rays of the sun and the hot easterly winds. The
colouring of the Steppe changes as if by magic, and only the silvery
plumes of the _kovyl_ (_Stipa pennata_) wave under the wind, giving
the Steppe the aspect of a bright, yellow sea. For days together the
traveller sees no other vegetation; even this, however, disappears
as he nears the regions recently left dry from the Caspian, where
salted clays covered with a few _Salsolaceoe_, or mere sands, take
the place of the black earth. Here begins the Aral-Caspian desert.
The Steppe, however, is not so devoid of trees as at first sight
appears. Innumerable clusters of wild cherries, wild apricots, and
other deep-rooted shrubs grow in the depressions of the surface,
and on the slopes of the ravines, giving the Steppe that charm which
manifests itself in popular poetry. Unfortunately, the spread of
cultivation is fatal to these oases (they are often called "islands"
by the inhabitants); the axe and the plough ruthlessly destroy
them. The vegetation of the _poimy_ and _zaimischas_ in the marshy
bottoms of the ravines, and in the vall