to which the forests of western tropical Africa belong. The forest 

 vegetation of equatorial and West Africa constitutes, therefore, one 

 flora, and to that extent exhibits the characteristics of an island flora. 

 The extent of the flora, both internally as regards equatorial Africa 

 and externally as regards connections north and south and with other 

 countries, is ascertained from an examination of the distribution of 

 genera, and in more circumscribed areas by the distribution of species. 

 The reason for emphasizing this point is that at the present day there 

 is not one equatorial belt of forest, but a western forest belt stretching 

 from western Liberia to the middle of the Gold Coast and the equatorial 

 belt stretching from the east of Lagos eastwards. The examination 

 of genera and species shows that formerly this was undoubtedly one 

 undivided belt, probably including Sierra Leone at least within its 

 western boundary, and reaching as far north as the seventh parallel, 

 and probably considerably farther. 



A consideration of the types of vegetation found in West Africa 

 shows that the Gold Coast groups are but portions of the main belt, 

 for the political boundaries of the West African Colonies are not along 

 natural lines. Consequently it is better to adopt the names and divisions 

 of the zones of vegetation as defined by M. ChevaHer in " Les Comptes 

 Rendus," Tome 149, 1909. 



Three distinct zones are indicated. First, the SaheUenne Zone, 

 characterised by some of the scrubby desert species, and by many 

 woody species of small height growth, the soil being almost always 

 sandy and exposed. Secondly, the Sudanese Zone, the largest of the 

 three, comprised generally of laterite plateaux, bare in the dry season, 

 but becoming clothed with grass and leguminous plants in the rains ; 

 the trees of various species and often reaching a fair size, but never 

 forming thick or impenetrable forests, and rarely interlaced with lianes. 

 Thirdly, the Guinea Zone, comprising the coastal regions and marshes, 

 often cut up by estuaries and large stretches of mangrove ; in the 

 interior often hilly and cut by the ravines of rivers and their tributaries, 

 the forest dense and interlaced with giant creepers ; the water courses 

 bordered by bamboos. Elms and Raphia. 



Of these three the Sah61ienne Zone is not represented locally, but 

 both the Sudanese and Guinea Zones are found in the Gold Coast and 

 its dependencies. 



As has been stated above, at the present day there is not one 

 continuous forest belt throughout the West Coast, but a western portion 

 and a central equatorial belt. M. Chevalier states that, left to itself, 

 the forest of West Africa is able to gain ascendency over the grass and 

 recover its former area, as in some cases, notably in the mountains 

 to the north-west of the Ivory Coast, such advance of forest has actually 

 been observed. But these are isolated cases and, on the whole, the 



