Of these, two of large extent occur in the basin of the river Danube,
separated by the gorge of the “Iron Gate,” formed where the Balkan and
Carpathian ranges approach most closely. The upper plain, circled about
on all sides by mountains, is that of _Hungary_, over which corn fields
interchange with pastoral steppes well stocked with horses and cattle,
sheep and swine, merging in some parts into marsh lands or into dusty
sand flats. Where the plain begins to rise to the sunny hills, the
Hungarian grape ripens to yield its famous wines. The lower plain of the
Danube, which might be called a branch of the vast Russian lowland, is
that of _Roumania_, with its far-stretching treeless heaths and pasture
lands supporting great herds of cattle and horses, passing into wide
reed swamps which characterize the delta of the Danube.
Corresponding to the Roumanian plain is that of _Lombardy_, perhaps the
most productive region of Europe, in which the irrigated meadows may be
six times mowed in the year, and where wheat, maize, and rice, and wine
and dairy produce, are yielded in vast quantity.