Packard.] INSECTS OF THE POND AND STREAM. 145 
tion of this tube being maintained by a pencil of radiating 
hairs, attached to a shorter projection at the end of the 
body. The air is rapidly absorbed by the unusually large 
trachea, nearly filling the longer tube. After taking a fresh 
breath it often swings its head around, mouth upwards, its 
tail being the pivot, mowing the surface of the water, if 
clouded with decaying matter, with its jaws. The young 
Anopheles, the fty of which is the four-spotted mosquito 
found in houses late in autumn and early in spring, is a 
surface breather. But the head and thorax are scarcely 
heavier than the hind body, and along its whole length are 
tufts of hairs which spread out and act as floats to the body. 
The mouth-parts are tufted more distinctly than in the 
Fig. 109. 
Mosquito larva and pupa. 
young mosquito. In this larva the body ends in four fleshy 
finger-like appendages, in which the tracheae may be dis¬ 
tinctly seen. 
In its pupal stage the mosquito is quite a different being. 
Its life is regulated by a new code. It scorns food of all 
sorts, and like some religious devotee lives on air alone, and 
that in homeopathic doses. The enormous thorax is almost 
a deformity, and now, instead of breathing through its tail, 
it bears two club-shaped respiratory tubes on its back (Fig. 
109, d). These are situated on the site of the future tho¬ 
racic spiracles of the fly. 
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