If we throw a glance, moreover, at the plants under cultivation, we find them equally important: rice, earth-nut, _Sorghum_, Indian corn, the cocoanut, the elegant and useful tree which gives to man almost all the necessaries of life, supplying him at once with shelter, food, light, heat, and clothing; the clove-tree (_Caryophyllus aromaticus_), the unopened flower of which is the well-known clove; pepper (_Piper nigrum_), the fruit of which, gathered before maturity, has been constantly brought to Europe since the expedition of Alexander the Great; and the betel (_Chavica Betel_), with bitter and aromatic leaves, in which the southern Asiatics inclose a few slices of the areca-nut, which they chew; the tamarind (_Tamarindus indica_), a magnificent tree, the fruit of which incloses a pulp of acid flavor; the mango (_Mangifera indica_), whose much-vaunted fruit has a sweet and richly perfumed flavor accompanied with a grateful acidity; the mangosteen (_Garcinia Mangostana_), whose berry incloses, under a bitter and astringent epicarp, a delicious pulp; the banana, whose yellow-clustered fruit, each six or eight inches long, furnishes a very nourishing food; the rose apple (_Jambosa vulgaris_), the guava (_Psidium pomiferum_), with yellow fruit of the size of a pear; oranges, watermelons, sugar-cane, and coffee. Africa, like Asia, presents three very distinct regions: 1st, the Northern, which comprehends the Mediterranean littoral and the Sahara; 2d, the Central, which is tropical; 3d, the Southern, which includes the Cape of Good Hope. The Mediterranean region, by which we mean the African littoral bathed by the Mediterranean, includes Algeria from the northern slopes of the Atlas to the sea, and the Delta of the Nile. This part of Africa represents, in many respects, a vegetation analogous to that of South Europe. In the mountain region of North Africa all the plants of Central Europe may be cultivated with advantage. The vine prospers in the neighborhood of Tlemcen, Milianah, Mascara, and Medeah, where the colonists and even the natives have undertaken its cultivation. The olive, so generally spread over North Africa, constitutes one of the chief sources of wealth to the Kabyle tribes. The cork-tree forms immense forests in the lower mountain region of the littoral: in the province of Constantine, gathering the cork has become an important trade since its conquest by France. With respect to the Sahara, M. Cosson, a traveler and botanist, thus expresses himself: