318 NORTH AMERICAN INSECTS. 
can not fail of exciting contemplations of the most serious 
kind. Indeed, one has no idea of the amazing beauty of 
these diminutive creatures until he has observed them 
through a microscope. : 
The common Mosquito (Culex pipiens) of America, as 
well as of Europe, is gray, and has immaculate wings. 
The females are the principal tormentors, hovering up and 
down in large swarms near the water, and at night perse- 
cuting man and beast with their stings, as well as their in- 
tolerable music. 
Their visible proboscis is not the sting itself, but only 
the case or scabbard which incloses the instruments for 
piercing the skin and sucking our blood. These instru- 
ments are five bristles, which may be seen protruding from 
the scabbard, or proboscis, if you take hold of the neck of 
the insect and squeeze the proboscis. These bristles, cut off 
and placed under the microscope, appear like lancets with a 
hook in the end, which remains in the wound made by it, 
if the insect be driven away suddenly when sucking, and 
which causes greater pain and inflammation than if the in- 
sect is allowed to withdraw it when he has ceased sucking. 
After the hollow sting has entered the flesh about three- 
quarters of a line, and the insect has filled its body with 
human blood, the wound begins to itch and swell—not on 
account of the insignificant puncture, but on account of 
the venomous saliva which entered it, for the purpose, prob- 
ably, of diluting the blood. We see the same thing when 
a fly drops some liquid from its proboscis upon a piece of 
sugar, in order to dissolve it and diminish its strength, so 
that it can suck it up. The saliva, therefore, performs the 
same office in insects that it does in mammals when mas- 
ticating their food. 
Mosquitoes deposit their eggs in stagnant water, and 
this is probably the reason that they are more numerous in 
wet summers. If a hogshead or barrel of water be placed 
