524 



SCmJS'CE. 



[Vol. IX., No. 225 



the region of forests savannas are not wanting. 

 Wherever the local climate is dryer, we find them, 

 and the irregularity of the rainfall in this region 

 may sometimes destroy woods. But besides this, 

 the methods of agriculture applied by the natives 

 are destructive to the forests, which are burnt or 

 cut down. As the natives frequently remove 

 their habitations from one place to another, large 

 tracts of forest are annually destroyed. 



The natives distinguish two forms of vegeta- 

 tion, — the campina and the forest. European 

 travellers, particularly Pechu6l - Loesche, who 

 studied the vegetation of Central Africa, de- 

 scribes the character of the country as follows : 

 In the campina, from one-fourth to one-half of the 

 ground remains barren, while the rest is covered 

 with grasses from three to six feet high. This is 

 more particularly the case in the open campina. 



VEGETATION OP CENTRAL AFRICA (according to O. Drude). 



Dark }mes, evergreen woods; light lines, woods with de- 

 ciduous foliage and savannas ; dots, tropical alpine 

 flora. 



which consists of Andropogon, Cymbopogon, and 

 Ctenium. The period of vegetation is the season 

 of thunder-storms, but before its end the seeds are 

 ripe and the grasses begin to fade and dry up. 

 There are only few shrubs mixed with these 

 grasses, — Leguminosae, Compositae, Malvaceae, 

 and Verbenaceae. Another characteristic form of 

 vegetation is the bush, which is composed of ever- 

 green thornless shrubs from twelve to fifteen 

 feet high, with rigid leaves of a bluish or dark- 

 green color. The bush is found on hills and 

 slopes or on the plains in patches surround- 

 ed by the campina. Pechuel - Loesche distin- 

 guishes besides these the ' bush woods ' and ' high 

 woods.' The genera of these are identical, but the 

 imi)ression is very different according to the prev- 

 alence of high trees or of lower forms. In the 

 ' high woods,' evergreen-trees prevail, the crowns 

 of which are interwoven with climbers, while 



enormous trees with deciduous foliage tower above 

 them. Though the multiplicity of form of the 

 American tropical woods is not found here, they 

 are described as not less impressive and grand than 

 any other tropical forests. 



The accompanying sketch-map shows the dis- 

 tribution of this kind of woods. They occupy 

 almost the whole of the Kongo basin except the 

 highlands of Karagwe and the region adjoining 

 the watershed between the Kongo and Zambezi. 

 On the east coast thej' are confined to a nari-ow 

 belt adjoining the coast. The rest of the country 

 except the summits of the highest mountains is 

 occupied by savannas, and forests of trees with 

 deciduous foliage. In East Africa the district be- 

 tween the Kilima Njaro and Lake Rikwa is almost 

 exclusively occupied by savannas. The caravan 

 routes from the east coast to the Tanganyika 

 cross it in Ugogo. 



The deserts and steppes north and south of the 

 fertile belt of Central Africa do not belong to the 

 district under consideration, but are confined to 

 the area north of latitude 10*^ north, and south of 

 latitude 15° south. On the west coast, however, 

 vegetation becomes more scanty south of the 

 Kongo, and in latitude 12° south some parts have 

 the appearance of real steppes. 



The latest additions to our knowledge of Cen- 

 tral Africa are the exploration of the Mongalla 

 and of the tributaries of the Obangi. We referred 

 in Science of April 1 to Baert's exploration of the 

 Mongalla. From the map in' Le mouvement geo- 

 grapMque of May 8, it appears that Baert reached 

 latitude 2° 50' north, and longitude 21'=' east. The 

 mouth of the Mongalla on Baert's map is 35' 

 farther east than on Grenf ell's map. The explora- 

 tion of this river is very ioiportant, as it belongs 

 to the unknown region of the watershed between 

 the Welle and the Kongo. The only map of the 

 tributaries of the Obangi yet published is that of 

 the Ngiri, a small river draining the peninsula be- 

 tween the Kongo and the Obangi, In latitude 4° 

 north the explorer of the Obangi, Captain van 

 Gele reached the cataract of Zongo, which pre- 

 vented further progress. This cataract is formed 

 by a range of hills six or eight hundred feet high, 

 through which the Obangi has cut its valley. The 

 problem of the western tributaries is very essen- 

 tial to our knowledge of the orography of Africa, 

 as the north-westerly rim of the large central 

 plateau is still totally unknown. 



— Dr. H. Labonne, who made some important ex- 

 plorations in Iceland last summer, left Cherbourg 

 on April 15, to continue his studies on the geysers 

 and glaciers of that island (Gaz. geogr., April 21). 



