MOSQUITOES. 189 
food it must be able to save itself when disturbed and it 
does so the very moment the surface of the water becomes 
agitated, by a few strokes with paddle-like swimming-or- 
gans located at the tail. The trumpet-shaped breathing- 
tubes contain upon their inner surface a large number of 
peculiar hairs, which prevent the water from entering. Like 
the larva the pupa has to come frequently to the surface to 
breathe air, and if not disturbed always hangs suspended 
from the surface-film of the water. In a few days the last 
transformation takes place, which is well shown in (ce). 
The pupal skin splits open in the back, thus forming a boat, 
and the adult and winged mosquito works its way very 
carefully out of the many fine skins that enclose its various 
members. As soon as the wings are expanded and dry the 
insect flies away, now breathing air in the usual manner of 
insects by means of fine openings located in the sides of the 
thorax and abdomen. We have here the interesting fact 
that the same insect has to breathe air in three different 
ways and by three different sets of organs, each seen to be 
most wonderful in structure if carefully studied by means of 
a microscope. 
Thus far both sexes were very similar in structure, but 
if we now study them in their winged shape we shall find 
them quite different. The male (¢) is distinguished by very 
large and feather-like feelers, and by rudimentary mouth- 
parts. The female (d and c) has smaller feelers, and a hard, 
long and slender proboscis, decidedly well adapted to suck- 
ing blood. Ofcourse in nature but few of these bloodthirsty 
females ever have an opportunity to obtain such food, and 
they must subsist upon something else. It is suspected, and 
the experiments made this summer but not yet finished seem 
to prove it, that females inbibing such blood die in conse- 
quence. Where is the benefit to the speciesif such is the case? 
Regions in which stagnant water abounds are famous, 
or rather infamous, on account of the vast number of such 
insects, and their presence is easily accounted for. But we 
find them many miles away from water and sometimes in 
equally large numbers. Where do theycome from and where 
do they breed? 
