KENYA COLONY. 287 



temperature ranges between 59 degrees at 7,000 feet and 79 degrees 

 at Mombasa on the east coast. Frost is practically unknown 

 below 9,000 feet. 



The rainfall is greatest on the west, and gradually diminishes 

 towards the east. The records are not sufficient to give a detailed 

 account of it ; at an altitude of G,600 on the western slope of the 

 Mau mountain the average fall is 76 inches, while it is 43 inches 

 between Nairobi and Kussumu. There are two seasons of rain, 

 from March to May and November to October ; to the west of the 

 Rift valley the former extends into August, while the rainfall 

 during the latter is less plentiful. 



The mountain forests, situated in the heaviest rainfall areas, 

 play a most important part in the economy of the country ; they 

 protect the hill sides against erosion, and they conserve and 

 maintain the flow of water in the streams on which the prosperity 

 of agriculture depends, besides providing fuel, coal and oil not 

 having been found in the country. 



2. Main Types of Forest Growth. 



These are as follows : — 



(a) Mangrove Swamps on creeks and inlets of the coast, the 

 principal species being Bruguiera gymnorhiza, Rhizophora mucro- 

 nata, Ceriops Candolliana, Sonneratia caseolaria, Avicennia 

 officinalis, Lumnitzera racemosa and Heritiera liUoralis. 



(b) Coast Forest, situated in the coast belt under the influence 

 of moist sea winds, formerly covered large areas, but only isolated 

 groups remain now, owing to shifting cultivation. The chief species 

 are Afzelia cuanzencis, Trachylobiuni Horneniannianum (Gum 

 Copal), Comhretum Schumannii, Tamarindus indicus, Berlinia 

 spp., Brachystegia sp., Erythrophloeiim guineense, Mimusops sp. 



(c) Nyika Forest covers vast areas of waterless arid country 

 between the coast and the highlands ; it consists of impenetrable 

 thorn bush, but near the coast the trees are larger and form real 

 forests of Acacia spp., Brachylcena sp., Afzelia, Dalbergia 

 Melanoxylon (Ebony), Cynometra sp., and numerous other species 

 not yet identified. 



{d) Plains Forest on small detached areas below the main 

 mountain forest at an elevation between 5,000 and 6,500 feet only 

 on laterite soil, the more important species being Brachylcena 



