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. 



