228 ' INSECTA. 
rently with fewer articulations in the females. The proboscis is 
composed of a membranous, cylindrical tube, terminated by two lips 
forming a little button or inflation, and of a sucker consisting of five 
squamous threads which produces the effect of a sting. The wings 
are laid horizontally, one over the other, on the body, with little 
scales. 
The torment we experience from these Insects, particularly in the 
vicinity of low grounds and water, where they are most abundant, is 
well known. Thirsting for our blood, they pursue us everywhere, 
penetrate into our dwellings, particularly in the evening, announce 
their presence by a peculiarly sharp hum, and pierce our skin with 
the fine sete (dentated at the extremity) of their sucker; in propor- 
tion as they sink them into the flesh, the sheath bends towards the 
pectus and forms an elbow. They distil a venomous fluid into the 
wound, which is the cause of the irritation and swelling experienced 
from their attacks. It has been remarked that we are only perse- 
cuted by the females. In America, where they are known by the 
names of Marangouins and Moustiques or Musquetoes, the inhabi- 
tants, as in other countries, defend themselves from them by sur- 
rounding their beds with gauze or a Mosquetoe-bar. The Laplanders 
remove them by fire and rubbing the exposed parts of their bedy 
with grease. These Insects also feed on the nectar of flowers. 
The female deposits her eggs on the surface of the water, and 
crossing her posterior legs near the anus, and slowly separating 
them as the ova are extruded, places them side by side in a perpen- 
dicular direction; the entire mass resembles a little bateau floating 
on that element. Each female lays about three hundred eggs in the 
course of the year. These Insects frequently survive the most in- 
tense cold. Their larve swarm in the green and stagnant waters of 
ponds and ditches, particularly in spring, the period at which those 
females lay their eggs who have passed through the winter. They 
suspend themselves on the surface of the water in order to respire, 
with their head downwards. They have a distinct rounded head, 
furnished with two (species of) antennz and ciliated organs, by the 
motion of which they draw alimentary matters within their reach; 
a thorax with tufts of hairs; an almost cylindrical and elongated 
abdomen, much narrower than the anterior part of the body, divided 
into ten rings, of which the antepenultimate bears (above) the respi- 
ratory organ, and the last is terminated by radiating sete and ap- 
pendages. These larve are very lively, swim with considerable 
velocity, and dive from time to time but soon return to the surface. 
After some changes of tegument, they then become nymphs, which 
still continue to move by means of their tail and its two terminal 
