The mid-European region includes southern Russia, Germany, Holland, Belgium, Switzerland, the Tyrol, and the British Isles, Upper Italy, and the greater part of France. This region, whose exact limits it would be difficult to trace, is very different from the preceding. It is milder, more temperate; its woods and forests consist essentially of oak (_Quercus Robur_), to which we may add chestnut, beech, birch, elm, hornbeam, alder, etc.; but the oak predominates. These trees, all of which lose their leaves during winter, give to the landscape a very peculiar feature, varying with the season. This region is especially favorable to the cultivation of the cereals. An oblique line, drawn from east to west, with certain inflections of its course, but ranging between the forty-seventh and forty-eighth parallel, and inclining a little toward the north, would divide it into two zones--one, the Northern, in which the vine and the mulberry yield to the rigor of winter, whose forests are chiefly composed of conifers, where the culture of the apple and pear takes their place, and which includes more _Cyperacæ_, _Rosaceæ_, and _Cruciferæ_; the other, the Southern, characterized by the culture of the vine, the mulberry, and the maize, and in which _Labiatæ_ begin to predominate. In the Southern region, the Mediterranean forms the centre. It is a vast basin, whose shores present a vegetation which, if not identical, is at least analogous in its whole extent. _Labiatæ_ abound there, and in certain seasons the air is filled with their sweet perfume. To this extensive family we may add a large number of _Caryophyllaceæ_, _Cistaceæ_, _Liliacæ_, and _Boraginaceæ_. The Mediterranean draws its distinctive character, however, from the vast extent of uncultivated country, where the kermes oak, _Phillyrea_, the evergreen oak, and various half frutescent Labiatæ, reign supreme. These plants more especially abound in Italy, Spain, Greece, Algeria, and in the northern portion of Asia Minor. Nevertheless, a new vegetation makes its appearance at Rhodes and Jaffa, which becomes closely connected with that of Egypt. The vegetation of the Mediterranean often presents itself with a smiling and agreeable aspect. Clumps of odorous myrtles, _Arbutus_, and _Vitex Agnus-castus_, frequently occur on its shores; magnificent oleanders, whose praises have been sung by the poets, occupy the edges of the brooks. In Italy, Sicily, and Spain, the orange-trees bear without cessation flowers and fruit. The prickly pear (_Opuntia vulgaris_), and the American _Agave_, naturalized here, form impenetrable hedges in the southern parts of these countries, to which they give a marked and very characteristic landscape. The forests consist essentially of the evergreen oak (_Quercus Ilex_), whose persistent leaves remain until after their third year, and whose acorns, which have a very agreeable taste, form a considerable portion of the people’s