﻿140 JAS. J. SIMPSON — ENTOMOLOGICAL 



geographical situation of the colony, the main topographical features, the river 

 and mountain systems, the climate and rainfall, and the various types of vegeta- 

 tion and their distribution, have received consideration. 



A short description of the main characteristics of the regions I was unable to 

 visit have also been given, so that when records from these localities come to 

 hand it may be possible to correlate them with others already known as to 

 similarity of environment, climate, etc. 



A map has been prepared to show the distribution of the various species of 

 Glossina in the colony, and on it are included all available authentic records. 

 A short chapter has also been added emphasising the main features of this 

 distribution. 



A list of all the blood-sucking insects, and other arthropods has been drawn 

 up, and though this list is already large, there is little doubt that further work 

 will still augment the number. At the same time, in the case of many of the 

 species, little is known of their general distribution. 



A few notes on the different protozoal diseases found in the colony are also 

 given, but our knowledge of the distribution or endemicity of these is far from 

 complete, while, in this connection also, a resume of what is known of the pre- 

 valence of the various species of Stegomyia has been added. 



In my previous reports I have discussed at some length a few of the many 

 problems which require further investigation, and, as these are equally applicable 

 to Southern Nigeria, there is no necessity for reiterating them. The same holds 

 good with regard to remedial measures and recommendations, so that, with the 

 exception of a few special cases, these have also been excluded from this report. 



Sufficient has been said, therefore, to indicate the lines along which this report 

 was possible and on which it has been framed, but I would once more like to 

 point out that, although it was impossible for the writer to attempt to solve any 

 particular problem, it is hoped that this account of the work done, and its general 

 bearing on distribution, may help to stimulate others to an elucidation of the 

 important bearing of insects in their relation to disease, and indicate lines along 

 which such work may be most profitably accomplished. At the same time it may 

 help to show how such difficulties as the identification of insects may be over- 

 come, and also how the most trivial observations may be utilised in the general 

 scheme of knowledge. 



I. Geography of the Colony and Protectorate. 



O) Position and Extent. 



The Colony and Protectorate of Southern Nigeria, one of the oldest and most 

 productive of the British West African Possessions, is situated in the extreme 

 east of the Gulf of Guinea. Its total area is estimated at about 77,500 square 

 miles, or nearly two-thirds of the United Kingdom. Owing to its irregularity in 

 shape, its extreme limits are separated by great distances, e.g., its eastern and 

 western boundaries lie approximately in 10° 15' E. and 2° 15' E., while the 

 northern and the southern limits are in 9° 10' N. and 4° 20' N. respectively. Its 



