Diptera, or Flies. 591 
immediately around its body, it eats the filaments of the 
cloth or fur, close to the thread of the cloth, or to the 
skin. This operation is performed by its jaws, which act 
in the manner of scissors. The pieces are cut into con- 
venient lengths, and applied, with great dexterity, one 
by one, to the outside of its case ; and to this it fastens 
them by means of its silk. Its covering being thus 
formed, the little Caterpillar never quits it but on the 
most urgent necessity. When it wants to feed, it puts 
out its head at either end of its case, as best suits its 
conveniency. When it wishes to change its place, it 
puts out its head and its six fore legs, by means of which 
it moves forward, taking care first to fix its hind legs 
into the inside of the case, so as to drag it along. After 
having changed within its case into a chrysalis, it issues, 
in about three weeks, a small, winged, mealy-looking 
Moth, of silvery drab colour, too well known to almost 
every mistress of a family. The best mode of destroying 
this insect, when in the cloth, is to place a saucer of oil 
of turpentine with the articles affected in a close place, 
when the vapour raised by the warm air will imme- 
diately destroy it. Should the Caterpillar be old and 
strong, it may be necessary to brush the clothes with a 
brush, the points of which have been dipped in turpen- 
tine. Camphor wrapped up with furs will protect them 
from the Moth. 
Order VII. Diptera, or Flies. 
This order is characterised by having only two wings, 
which are transparent, and which have two little mov- 
able bodies, called halteres or balancers, placed close 
behind them. The head is almost covered with a pair 
of enormous eyes ; and the mouth is furnished with a 
proboscis or sucker. The legs are long in proportion to 
the body, and are in many species terminated by two or 
three small cushion-like expansions, which, it is sup- 
posed, enable them to walk on glass. Each foot has also 
two hooks or claws. 
