RESEARCH IN BRITISH WEST AFRICA. 307 



deciduous forest, and the pure savannah are also more or less in evidence. 

 Wherever the dry season is short and there is a certain amount of rainfall 

 practically throughout the whole year, the monsoon forest is met with ; while, on 

 the other hand, when the rainy season is extremely short and the dry season is 

 accompanied by the hot dry wind from the Sahara, the predominant feature is 

 long grass, and few if any trees or shrubs are to be seen. Consequently, according 

 as the climatic conditions of any particidar region are nearer one or other of 

 these types, dense forest, open forest, or savannah will be found in excess. 

 Further, the fierce fires which are so common during the dry season have a 

 marked influence on the vegetation, inasmuch as they materially affect the 

 woodland growth, but not the grass, so that where these fires are prevalent 

 savannah forest approaching pure savannah is found. 



Passing from the north to the south, we find an almost regular increase in the 

 amount of non-deciduous arboreal growth, and a consequent decrease in deciduous 

 low scrub and grass. On the other hand, the banks of the rivers and streams, 

 where the soil is constantly moist, are covered with a dense forest growth, and 

 this is also foimd in numerous places where there is permanent telluric moisture 

 due to local physical conditions ; many of these places, if judged by the amount 

 of rainfall and the length of the dry season, would not appear suitable for sucli 

 vegetation. 



These local patches are fovind scattered all over the southern half of the 

 Protectorate, but do not seem to extend into the savannah region of the north. 

 They are known by the local name of " kurimi," and as this term will be 

 frequently used in the narrative, a short description may not be out of place 

 here. Occasionally, these are of very limited extent, but sometimes stretch in 

 narrow belts of 50-200 yards in width for several miles. The soil is continually 

 moist and covered with a thick layer of leaves and decaying humus. Large non- 

 deciduous trees are abundant, and there is a dense undergrowth of thick scrub, 

 the whole being bound together by thick, woody and succulent lianas (PI. XIV, 

 figs. 1 and 2). Grass and herbs are practically absent. The larger trees have 

 frequently well developed buttresses, and others have stroing aerial roots. Such 

 belts are very difficult to penetrate, but when an entry has been made, the dense 

 nature of the shade, the fall in the temperature, the humidity of the atmosphere, 

 and the almost perfect stillness are points which at once strike the intruder. As 

 these are practically always haunts of Glossina palpalis, the importance of a 

 knowledge of their origin, extent and distribution becomes evident, but this will 

 be referred to in greater detail in the narrative. 



The savannah forest is what might be termed park-like in character, and is 

 the predominant feature in the landscape ill the centre and northern parts of the 

 Protectorate. Grass is abundant, as also are low deciduous shrubs, while scat- 

 tered throughout are trees, varying in nimiber and size in the different parts. 

 This type of country is more suitable for G. tachinoides and G. submorsitans than 

 for G, palpalis, and a survey of such a region generally shows that where trees 

 are abundant G. tachinoides is found, while where: low shrubs and grass pre- 

 dominate G. snhmorsitans is more common. 



