CHAPTER IV.
NORTH SENEGAMBIA: SENEGAL.
General Survey.
OUTH of the Saharian region the natural frontiers of Sudan are indicated by no precise line, but rather by a narrow zone skirting the north bank of the Senegal and of the Joliba (Niger) eastwards to and beyond Timbuktu. Here takes place the transition from the dry to the rainy climate, and to these contrasts correspond others in the aspect of the land, of its flora and fauna, origin, customs, and institutions of its inhabitants. Senegambia is thus well defined northwards by the valley of the Senegal and the scarp of the plateaux which mark the geological frontier of the Sahara.
The river valley, although penetrating not more than 600 miles inland, constitutes one of the characteristic features of the continent. Here begins the real Africa, separated by the desert from that Mediterranean Africa which forms an intermediate region between the northern and southern sections of the globe. The Senegal constitutes an ethnical parting-line between the Berbers and Arabs on its right, and the Nigritian population on its left bank. In a general way the river may be said to mark the starting-point of the transverse line which runs between the domains of the brown and black races. Here two distinct worlds confront each other.
But towards the east and south Senegambia has no precise limits; in these directions the transitions take place imperceptibly, while the geographical features are marked by no striking contrasts. The water-parting between the affluents of the Senegal and Joliba is faint and uncertain, the traveller passing from one fluvial basin to the other without detecting any change in the aspect of the land. On the other hand, the ranges and groups of uplands in south Senegambia continue to develop towards the south-east as far as Liberia and the Ivory Coast, parallel with the continental seaboard. Nevertheless a certain geographical unity is presented by the oval space comprised between the Atlantic, the Senegal, the Upper Joliba, the Rokelle, and the plateau separating the sources of the two last-mentioned streams. The whole land may here be said to be grouped round the central mass of the
