RESEARCH IN SIERRA LEONE. 155 



to these, one comes across a small patch near every town and village which has 

 been preserved for fetish purposes. These groves are known as the " Bnndu 

 and " Porro " Bush, and their sacred nature prevents their destruction. 



As the distribution of the various species of Glossina in Sierra Leone depends 

 almost entirely on the distribution of the different zones of afforestation, it 

 might be well to note briefly the regions where each type is at present to be 

 found. 



(a) Rain forests. This name is given to a characteristic tropical forest in 

 which the trees reach a height of 100 feet and over, and in which there is little 

 or no liana growth. Nearly one-third of the Peninsula of Sierra Leone is 

 covered with forest of this primeval type, Avhile other mountain forests are found 

 on the Kessewe Hills, south-east of Yonnibanna, and on the Kagnari Hills, 

 20 miles north of Bo (on the railway). These hills extend in a north-easterly 

 direction for ten miles, from Mongheri to Makump. Rain forest is also found 

 on the Kambui Hills north of Kennema (on the railway) ; on the Nimmini 

 Mountains around Panguma ; on the hills around Bumbonla ; on the Loma 

 Mountains (in Koinadugu district) ; also in the Grola Forest near Daru and 

 Kailahun (Kanre Lahun) ; and on the right bank of the Mano River near 

 Bandasuma and Mendikama. 



(b) Savannah forests. When primeval rain forest is destroyed it is replaced 

 by a drier type, namely savannah forest, and this in turn gives way to pure 

 savannah. Savannah forests are to be found m the north of the Ronietta, 

 Panguma, and Konnoh districts, and also in Karene and Koinadugu districts. 

 There we find open woodlands with trees which rarely exceed 30 feet in height 

 and which stand at some distance from each other — the intervening space being 

 covered with grass and other herbaceous plants. 



(c) Fresh-water swamp forests are composed of edaphic forms, and occur in 

 swamps and swampy places. The vegetation is different from that of other 

 forests, and bamboos, wine palms (Rapha vinifera) and screw pines (Panda nits 

 spp.) are predominant. The ground is covered with shrubs, ferns, and mosses. 

 No general idea of the distribution of these can be given, except that they occur 

 wherever there is low-lying ground and an abundance of telluric moisture. 



(d) Fringing forests also contain edaphic forms, but not so predominantly 

 as in the case of swamp forests. They are found along the banks of rivers 

 in the savannah country and owe their existence to the permanent supply 

 of water. 



(c) Mangrove forests are limited to the sea coast and are to be found along all 

 the creeks and in all the rivers up to the limit of tidal influence, e.y.^ from 

 Freetown to Port Lokko, almost to the town of Rokcll on the river of that name, 

 to Kambia on the Great Skarsies River, and to Waterloo. Especially are they 

 predominant in the vicinity of Bonthe on Sherbro Island, and in the numerous 

 creeks and rivers which open into this region. 



Without entering into any detail for the present, we might point out that 

 Glossina palpalis is to be found predominantly in the mangrove forest, fresh- 

 water swamp forest and fringing forest areas ; G. longipalpis is restricted almosl 



