RESEARCH IN BRITISH WEST AFRICA. 303 
it does not in any way aim at being exhaustive, but by showing how scanty our 
knowledge of this subject is, it may stimulate others to collect and make 
observations on the various species of insects which are harmful or beneficial to 
man and animals. 
For a proper understanding of the distribution of not only tsetse but also other 
insects, several general considerations have to be taken into account; for example, j 
the geographical position of the Protectorate, the general topography, the river 
systems, the nature and extent of the various types of vegetation, the climate 
and the rainfall. Hach of these has been discussed in a very general way, only 
in so far as they are likely to influence the problems with which we are here 
more intimately concerned. 
A short section has also been added on the chief tribes inhabiting the 
Protectorate, as, to a great extent, their distribution and mode of life have often 
a direct bearing upon the dissemination of disease. 
Several photographs (PI. viii.xv.) and two sketch maps (PI. vii. and xvi.) 
have alse been included to illustrate some of the points emphasised in the report. 
The former serve to show the various types of country either associated with 
or free from certain species of Glossina. ‘The first sketch map illustrates the 
general contour lines and river systems, while the second has been added as the 
region it depicts is uncharted on the larger map. 
The most recent map (scale 1:014 inches=32 miles) of the Protectorate has 
been reproduced to show the distribution of the various species of Glossina which 
occur there, and in it have been inserted all available authentic records, including 
those in the National Collection in the Natural History Museum. In another 
paper in this Bulletin,* I have discussed the question of the graphic representa- 
tion of the distribution of insects and disease on maps, and have suggested a 
scheme which has been adopted in the compilation of the present map, and which 
will be used in all maps published in colour in this Bulletin, and also in that of 
the Sleeping Sickness Bureau. 
The various sections in the Narrative do not follow the order in which the 
different parts were traversed by the author, but are arranged so as to form a 
more or less complete unit, and the whole route is shown on the accompanying 
map. 
A list of the blood-sucking insects and ticks hitherto recorded from Northern 
Nigeria has been drawn up as a guide to those interested in this work, and notwith- 
standing the fact that the number of species is already large, there is little doubt 
that many new species will be found to occur, chiefly in the northern part of the 
Protectorate. 
I. GEOGRAPHY OF THE PROTECTORATE. 
(a.) Position and Extent. 
The Protectorate of Northern Nigeria, the largest and most recently acquired 
of the British West African Possessions, is roughly rectangular in shape, and 
* Bull. Ent. Res. II, pt. 4, pp. 297-299. 
