566 
dipteha. 
the labrum and piercing needles to be inserted to a satisfactory depth. 
The insect injects an irritating saliva into the wound, possibly in 
order to produce a little local inflammation and so to draw a more 
plentiful blood-supply to the spot. This saliva passes down from 
the salivary glands in the thorax through a minute canal inside the hy- 
popharynx, and the hypopharynx also serves, by closing up the under 
side of the labrum, to form a tube up which the blood is sucked by the 
pumping action of the front part of the throat. Very soon after feeding 
the mosquito ejects through the anus a clear yellowish liquid, which is 
the fluid portion of the blood. 
The more solid matter remains in the stomach and is completely 
digested in one to four days, when the insect is ready to suck again. As 
Ixe. 
Fig 364. —(After Nuttall and Shipley) Transverse sections of mosquito's 
PROBOSCIS. LXE. LABRUM. MN. MANDIBLE. MX. MAXILLA. HP. HYPOPHARYNX. 
SAL. SALIVARY DUCT. THE LARGE SHEATH (DOTTED) IS THE LABIUM. THE 
RIGHT HAND FIGURE REPRESENTS THE MALE PROBOSCIS, WHICH HAS NO 
MANDIBLES. (COMPARE TaBANIIL®.) 
is probably the case with all blood-sucking flies, a meal of blood seems 
to favour the production of eggs, and in some cases is perhaps even a 
necessary preliminary to successful reproduction. The male mosquito 
is harmless and generally lives on the juices of plants and fruit. 
In pairing, the sexes come together in the course of the aerial dances 
in which they often indulge, and the actual copulation is in general very 
short. The males are easily distinguished from the females by their 
more bushy antennse and the shape of their genital organs, which 
include two hook-like claspers, these being plainly visible with the aid 
of a lens. The female lays her eggs in water. Those of the Culicince 
are generally stuck together to form the well-known little raft-like 
masses, while the Anophelince lay theirs singly, as also does Stegomyia, 
a Culicine. The eggs themselves vary in shape among the different 
