﻿144 JAS. J. SIMPSON — ENTOMOLOGICAL 



season, fresh-water swamp forest is to be found ; where the soil is more porous, 

 and where there are distinct wet and dry seasons, monsoon forest is in evidence ; 

 where the dry season is of still longer duration, the water supply very limited 

 and precarious, and the soil is of a light character, the savannah type is prevalent : 

 while in the river deltas and lagoon, where the tidal influence is felt and the 

 water is brackish, mangrove thicket is everywhere to be found. The dis- 

 tribution of these types in Southern Nigeria can be indicated only in a very 

 general way. 



Rain forest may be said to occupy all the areas with an annual rainfall of 

 about 76 inches and upwards, but exists in its most typical form in those regions 

 where there is a rainfall of 100 inches and over, and where the dry season is of 

 extremely short duration or almost entirely absent. These conditions are satisfied 

 to a greater or less extent around Ilesha, Ondo and Ijebu-Qde in the Western 

 Province, in the west and south-west portions of the Benin District in the 

 Central Province, and on the slopes of the Oban Hills and other high ranges in 

 the Eastern Province. 



" It is generally assumed that the moist portions of Southern Nigeria are very 

 densely wooded and that the bulk of the land is covered with high rain forest. 

 This, however, is far from being in accordance with the truth, and the mistake 

 has in most cases arisen from the fact that the main native paths and roads are 

 fringed on both sides with broad belts of high forest purposely left intact by the 

 inhabitants . . . The country is literally honeycombed with farms and their 

 overgrown abandoned sites." 



Scattered throughout the Colony are many swampy areas and rocky hillsides 

 impracticable for farming, and these have consequently been left intact and bear 

 dense high forests. With the exception of these areas the greater part of the 

 country, lying within the zone of rainfall mentioned, is covered with a secondary 

 growth of a much drier character and considerably less dense than the untouched 

 virgin rain forest. 



Fresh water swamp forests are composed of plants that have become adapted to 

 growth in permanently wet soil. They correspond to the kurimis of Northern 

 Nigeria, which I have already described at some length." No general idea of 

 the distribution of this type can be given beyond pointing out that they occur 

 chiefly along the banks of rivers and streams or are scattered irregularly amongst 

 other formations in places where there is permanent telluric moisture. 



The monsoon or mixed deciduous forests contain, as the name indicates, many 

 trees which become leafless in the dry season. They are less lofty than 

 the rain forests and not so dense. Lianes and herbaceous epiphytes are 

 abundant, and the contrast in appearance during the wet and dry seasons is very 

 marked. 



" As regards the distribution of the monsoon forests they are confined to those 

 tracts of country where the available water supply and the duration of the dry 

 season operate jointly in such a manner as, on the one hand, to exclude the 



Bull. Ent. Res. If, pt. 4, p. 307. 



