Many of the cereals are cultivated in Senegambia on a very large scale; but they differ wholly from those which engage the attention of the European agriculturist. Barley will not grow even on the most elevated plateaux, on account of the constant and excessive heat. It is true that it will germinate; but it develops so rapidly that it passes through all the phases of its vegetation in the space of a few weeks, and yields but impoverished ears empty of grains; it is useless to the people of Senegambia except as forage. But, on the other hand, there are numerous Gramineæ adapted to hot regions, which the natives cultivate for their uses. Among others I may name the Tocussa and the Coracan (_Eleasine Tocussa_ and _E. Corocana_), with their curved digitate spikes and productive seeds; the _Pennicellaria spicata_, or Guinea Corn, a very tall grass, somewhat resembling maize, whose long cylindrical culms or blades bear each a multitude of white round grains, which, ground into meal, form very savoury cakes, as you may read in Mungo Park's Travels; and the _Durra_, _Doura_, _Indian Millet_, or _Sorgho Grass_ (_Sorghum_), a coarse, strong, broad-leaved grass, four to eight feet high, with a round grain a little larger than mustard seed; it is the principal corn-plant of Africa, and exceedingly nutritious, the natives employing it in the preparation of a favourite dish named Kouskoussou. The cereals most widely cultivated in Senegal include the Colonial Millet (_Oplismenus colonus_); the Abyssinian Meadow Grass (_Poa Abyssinica_), called "Teff" in Abyssinia, whose seeds are used for making bread, and whose blades yield an abundant herbage; Rice (_Oryza sativa_), and different varieties of maize. Leguminous plants appear wanting in Senegal. Their absence is probably due to the same causes as those which we have indicated as affecting the growth of barley. Cabbages and the different salads grow, in fact, with a rapidity which prevents them from maturing; they flower in two or three weeks after being sown. The inhabitants consequently resort to those alimentary species which belong to hot countries, and which can only be obtained in Europe at an enormous expense and by artificial means. Among the plants with edible roots are various kinds of Yams (such as the _Dioscorea alata_); Batatas (_Convolvulus Batatas_); and the Manioc or Manihot (_Jatropha Manihot_),[99] better known as Cassava, which, although in itself a deadly poison, is easily deprived by heat of its noxious properties, and when roasted or boiled becomes a nutritious and highly savoury food. It yields the valuable farinaceous material of Tapioca. Its leaves are cooling and healing; from its seeds an excellent oil is procured; and the juice which drops from its root serves for empoisoning arrows. Good and evil are both strangely mixed in this important plant. [Illustration: VEGETABLE LIFE IN THE AFRICAN PLAINS.