64 
A Monograph of Culicidae. 
jungles during the day, returning from them towards night. 
Specimens of Anopheles were also found by him in other 
villages surrounded by jungle to the east of the town, where the 
people suffer much from malarial fever. It would seem as if this 
particular genus of mosquitoes clung to jungle.” 
It is quite possible that under certain conditions, such as the 
prevalence of forests and jungles near habitations, that these 
pests seek the shade and coolness there afforded during the hot 
part of the day, just as C. pipiens seems to prefer to take up its 
day habitation in shrubs and woods in this country. 
This, however, does not fit in at all with Colonel Giles’s state¬ 
ment, that “ mosquitoes have a tendency to leave houses to seek 
vegetable food at dusk, and again retreat to them shortly after 
sunrise.” 
Mosquitoes are most annoying indoors at night, and they, 
anyhow in the case of our British species, come to the windows 
at dusk, instead of leaving the houses. By keeping all windows 
shut, from an hour before sunset until it is quite dark, the 
numbers entering the house can be greatly reduced. 
THE EFFECTS OF WEATHER ON MOSQUITOES. 
Culicidae , like most insects, are very susceptible to changes 
in the weather. A certain amount of dampness seems almost 
essential to them at times, whilst a cold strong wind places them 
at a great disadvantage. After a good rainfall they often seem 
to appear in greater numbers than usual, no doubt because there 
are then formed pools in which they can breed, or vessels are 
filled in which the various Culex may deposit their ova. 
Regarding the effect of weather upon them, Mr. Tait, medical 
officer, writing from the Cayman Islands, says : “ There are 
several expanses of brackish water throughout these islands 
which seem to favour the propagation of mosquitoes. A slight 
rainfall, followed by heat, appears to favour their increase, 
while a continuous shower or a high wind is destructive to them.” 
Undoubtedly, a moderate rainfall filling up their breeding- 
places is essential to their increase; the pregnant females remain 
in a kind of dormant state until these conditions prevail. 
Dr. Christophers found the Anoptlielcs in numbers in native 
huts during the hot dry weather at Freetown, but they left to 
deposit their eggs as soon as the pools were ready after rains. 
