THE FOREST ZONE 43 



ravines, and is neither so abundant nor so extensive as that of the west coast. It 

 is more open, contains more trees indigenous to drier localities, and a considerable 

 number of bushes of more or less characteristic appearance. In the south-west the 

 forest-growth mainly consists of low, dark evergreens, which only along the coast 

 attain their full height of from 4 to 7 feet, trees being restricted to the moist 

 slopes and ravines of the mountains of Cape Colony. The evergreen shrubs of 

 the southern districts have leaves even smaller than those of the Mediterranean 

 countries, and, as a rule, inconspicuous, although thickly clustered, blossoms. With 

 them grow countless bulbous plants, thorny bushes, and succulent vegetation, trees 

 with pinnate leaves being rare throughout this tract. 



Until the opening up and exploration of East Africa it was generally supposed 

 that the forest districts of the west coast possessed an altogether peculiar fauna, 

 but since that date evidence has been gradually accumulating to show that a large 

 number of the genera of mammals long supposed to be peculiar to that area and 

 its hinterland really range right across the forest-zone to the Semliki and Uganda. 

 One of the first types formerly supposed to be peculiar to the western area, of 

 which the range was shown to include the eastern side of the forest region, was the 

 chimpanzi, which was recorded from the Niam-niam country by Schweinfurth, 

 and later on from Monbuttu by Emin Pasha. On the other hand, the gorilla, the 

 mandrill, and the drill still appear to be exclusively western types, although the 

 possibility of their discovery in the east must not be overlooked. As regards 

 other groups, specimens brought home by Major Powell-Cotton proved the 

 existence in East Africa of the otter-shrew (Potamogale), the water-chevrotain 

 (Dorcatherium), and the red tiger-cat ; while Mr. F. W. Isaac was the first to add 

 the bongo (Tragelaphus euryceros) to the eastern list. The yellow-backed duiker 

 has been shown to extend to the Ituri and Rhodesia, and the pigmy royal antelope 

 of Guinea is represented by a nearly allied species on the eastern side of the forest. 

 The red Congo buffalo and the red river-hog remain, it is true, distinctly western 

 types ; but the former has an analogue in the Semliki Bos caffer cottoni, of which 

 females and immature males retain the ancestral red, and bush-pigs of other 

 species represent the red river-hog on the eastern side of the continent. Although 

 originally discovered on the eastern side, the great black forest-hog (Hylochcerus) 

 has been found in the Cameruns ; and there is a possibility that the range of the 

 okapi may extend farther west than is at present known. Amongst smaller mammals, 

 the so-called African flying squirrels, better designated scale-tails (Anomcduridce), 

 the pigmy squirrels of the genus Nannosciurus, and the civets of the genus 

 Nandinia, have representatives on the eastern as well as on the western side of 

 the forest tract, although the beautifully coloured Poiana, the African phase of 

 the Indo-Malay linsangs (Linsanga), appears to be restricted to the west coast. 

 Most important of all, from the present point of view, is the comparatively recent 

 discovery of a potto (Perodicticus) in the Uganda forest. 



That the greater portion of the western fauna would eventually be found to 

 range over a large extent of the forest region was long ago predicted by Dr. A. R. 

 Wallace, who, however, continued to apply the terms western fauna and western 

 sub-region to the whole area and its animals. The time has now come when these 

 terms should be replaced by the designations forest fauna and forest sub-region. 



