GNAT. 
389 
angle from tlie abdomen, and terminating in a 
tubular opening, verged by four ovate scales, two 
of which exceed the rest in size : the whole animal 
is of a brownish colour, semitransparent, and be- 
set on each side the head, body, and tail, with 
large tufts of hair: its motions are very lively, 
and are conducted with a kind of convulsive ra- 
pidity, in different directions, and to a small di- 
stance at a time. It feeds on the minute vegetable 
and animal particles which it finds in plenty in 
the stagnant waters in which it resides, and, when 
arrived at its full growth, casts its skin, and com- 
mences chrysalis, the aspect of which is hardly 
less singular than that of the larva, the head and 
thorax appearing connate, and exhibiting a large 
oval mass at the upper part of the animal, while 
the body bends downwards beneath: the tliorax 
is furnished on each side with an upright short 
tube or spiracle, and it is from these parts that the 
animal frequently hangs suspended from the sur- 
face of the water: the tail is tipped with a pair of 
leaf-shaped processes. This chrysalis, like the larva 
from which it proceeded, is loco-motive, spring- 
ing about in the water nearly in a similar manner. 
When ready to give birth to the included Gnat, 
which usually happens in the space of three or 
four days, it rises to the surface, and the animal 
quickly emerges from its confinement. 
The Gnat is supposed to feed both on animal 
and vegetable juices, but perhaps chiefly on the 
latter, since, as Reaumur observes, of the mil- 
lions on millions which swarm in the marshy re- 
