MALARIA EXPEDITION TO NIGERIA 259 
have already been given, and it only remains to once again emphasise that an efficiently 
and intelligently executed system of extirpation is necessary. 
Under circumstances where at present ' segregation ' is impossible, the des- 
truction of breeding-places of Anopheles by drainage and other means already referred 
to would prevent the multiplication of the insect to some extent, and thus render the 
chances of infection much less. But it is to be remembered that so long as the mos- 
quito is able to obtain feeds of blood she can live for very long periods, during which 
she is continually on the watch for a suitable opportunity to deposit her eggs, and 
that the most unlikely and unusual sites would be utilised for that purpose. This 
shews the necessity for a thorough destruction of water collections and of the great 
difficulty of eradicating all, especially in native surroundings. 
But the creating and maintaining of breeding-places by such means as the con- 
struction of bad roads and footpaths, wells, unnecessarily uncovered, and so on, is 
inviting disaster. Half-a-mile has been fixed as the distance which should separate 
European and native quarters from a consideration of the habits of Anopheles. 
There is some considerable evidence for the assertion that these insects do not fly 
far and that they spend their lives very close to the spot at which they were hatched 
from larvae. It is extremely rare also that a breeding place for Anopheles is found at 
a greater distance than half-a-mile from the dwellings of man or from spots frequented 
by man. 
Objections raised against the principle of segregation. The only objections which 
we have become cognisant of, have arisen chiefly among the West African merchants. 
Excluding any reference to expense, the chief objection has been that such a segrega- 
tion as that suggested would seriously affect trade. It must be remembered that a 
distance of half-a-mile only has been fixed. We are totally unable to perceive how 
in any part of Nigeria such a procedure could in any way affect the trade at any of 
the factories we have visited. We urge that the principal trade is done, not with 
natives in the immediate neighbourhood of a factory, but with influential chiefs and 
middlemen, who generally dwell some distance up the rivers. The small retail trade 
done with natives living close to factories would be quite uninfluenced if they were 
removed to a distance of half-a-mile. In fact, some factories are situated at more 
than half-a-mile from any native town, and do excellent trade — to walk such a 
distance and carry back their wares is a mere nothing to a native. 
The only other objection heard of refers to social conditions. It must have 
arisen from a misunderstanding of what was suggested, probably from the roughest 
idea of what ' segregation ' might mean, — a wholesale removal of Europeans from 
among the natives, who were to be regarded as unfit for any intercourse or dealing. 
Such aggravated ideas are evidently absurd, and it is not clear how the adoption of 
the principle of ' segregation,' as described above, can in any way influence the present 
social relations between European and native. 
