the young. The number of other insects they destroy is scarcely to 
be conceived ; the mouth of their cave is, like that of a giant in the 
days of yore, strewed with the remains of prey. The eyes, that fila- 
ment which serves as a brain, and a small part of the contents of the 
body, are ail the savage eats, and he will kill fifty for a meal. 
Gnats 
These insects, too well known by the severe puncture they inflict, 
and the itchings theisce arising, afford a most interesting history. 
Before they turn to flying insects, they have been in some manner fishes, 
under two different for[ns. One may observe in stagnating waters, 
from the beginning of May till winter, small grubs, with their heads 
downwards, and their hinder parts on the surface of the w'ater ; from 
which part arises sidew'ays a kind of vent-hole, or small hollow fun- 
nel, and this is the organ of respiration. The head is armed with 
hooks that serve to seize on insects and bits of grass, on w hich it feeds. 
On the sides are placed four small fins, by the help of which the 
insect sw'ims about, and dives to the bottom. The larv® retain their 
form during a fortnight or three weeks, after which period they turn 
to chrysalids. All the parts of the v/inged insect are distinguishable 
through the outw'ard robe that shrouds them. The chrysalids are 
rolled up into spirals. The situation and shape of the windpipe are 
then altered ; it consists of two tubes near the head, which occupy 
the place of the stigmata, through w'hich the winged insect is one day 
to breathe. These chrysalids, constantly on the surface of the water 
in order to draw breath, abstain now from eating ; but uppn the least 
motion are seen to roll themselves up, and plunge to the bottom, 
by means of little paddles situated at their hinder parts. 
After three or four days’ fasting they pass to the state of gnats. 
A moment before, water was the gnat’s element ; but now, become an 
aerial insect, he can no longer exist in it. He sw'elis his head, and 
bursts its enclosure. The robe he lately wore turns to a ship, of 
which the insect is the mast and sail. If, at the instant the gnat dis- 
plays Ids w'ings, there arises a breeze, it proves to him a dreadful hur- 
ricane ; the water gets into the ship, and the insect, which is not yet 
loosened from it, sinks and is lost. But in calm weather the gnat 
forsakes his slough, dries himself, flies into the air, and seeks to pump 
the alimentary juice of leaves, or the blood of man or beast. 
The sting which our naked eye discovers, is hut a tube, containing 
five or six spicnia, of exquisite minuteness; .some dentated at their 
extremity like the head of an arrow, others sharp like razors. These 
spicula, introduced into the veins, act as pump-suckers, into which the 
blood ascends by reason of the smallness of the capillary tubes. The 
insect ejects a small q.uandty of liquor into the wound, by which 
the blood becomes more fluid, and is seen by the microscope passing 
through those spicula : the animal then swells, grows red, and does not 
quit its hold till it has gorged itself. The liquor it has ejected causes 
l>y its fermenting that disagreeable itching which we experience, and 
w hich may be removed by volatile alkali, or by scratching the part 
new'ly stung, and washing it instantly with cold water ; for if neglected, 
