INSECTS. 501 
but the most common is the House Fly. This insect lays 
its eggs in sinks, or any other place where there is decay- 
ing vegetable matter tolerably moist. The larvae, or 
maggots, are thick and fleshy, without legs, but having 
the mouth furnished with hooks, by means of which they 
drag themselves along when they wish to move. They 
go into the pupa state without throwing off the skin of 
the maggot ; and when the perfect insect appears, it forces 
off a kind of cap from one end of the pupa case, in order 
to make its escape. 
THE GNAT. (Culex pipiens.) 
THIS is an insect which deserves the observation of the 
naturalist, not only for the very curious conformation of its 
proboscis, (which so quickly and powerfully penetrates 
into our flesh, and through which it sucks our blood 
into its body,) but also for the several metamorphoses it 
undergoes before it arrives at its winged state. The Gnat 
deposits its eggs upon the slimy surface of stagnant water, 
and sets them upright one against another, in the form of 
a small boat ; after floating upon the water for several 
days in the first warm weather in the spring, as soon as 
they feel the time of hatching, the maggots, which the 
eggs contain, precipitate themselves to the bottom, and 
there feed for a fortnight ; after which time they undergo 
another transformation. The result is a curious animal 
with a kind of wheel in incessant motion, through whicli 
it imbibes the air at the surface of the water, to which it 
is obliged to repair every moment ; having passed about 
ten days in this state, its increase being at an end, it 
assumes another form, keeps longer near the surface, and 
at last the outer skin bursts, and the winged insect, 
standing upon the exuvice it is going to leave behind, 
smooths its new-born wings, springs into the air, and 
begins its depredations. The fecundity of the Gnat is so 
