In its general character the flora of this district seems to conform very much to what has been discovered on the table-land of Western Africa, of which the lower terraces form a narrow belt along the shore, and are distinguished for the wild luxuriance with which the African primeval forest seeks to rival the splendour of Brazilian nature. In contrast to this, the bush-forests in the higher parts of Tropical Africa, broken by the steppes, present in uniformity perhaps the most extensive district that could be pointed out in the whole geography of vegetation. Extending, as it does, from Senegal to the Zambesi, and from Abyssinia to Benguela, Tropical Africa may be asserted to be without any perceptible alternation in character, but that which is offered by the double aspect of steppe and bush on the one hand, and by primeval forest in the American sense on the other. On the west this is illustrated by the marked difference between the table-lands and the low coast-terraces, whilst in the interior it is exhibited by the distinction between the woods on the river banks and the flats lying between the river courses. Here, in the country of the Bongo and Dyoor, this, which may be designated as a duality, almost completely fails, on account of the small supply of water in the rivers and brooks; but in the land of the Niam-niam it is again very striking. Limited as have been the botanical collections of the few who have explored this immense region, they are still sufficient to justify us in estimating the relative abundance of species. When the collections from Java and Brazil are compared with those of Tropical Africa, it is certain that the plants of Africa are not altogether half so numerous.