68 THE INSECT WORLD. 
facilitate the progress of the animal on the smooth and slippery 
surfaces of the mucous membranes to which it fixes itself to feed, 
and perhaps also to increase the secretion of these membranes 
by the irritation occasioned by the bristles with which they are 
furnished.’’* 
Fixed by means of these hooks to the mucous membrane, which 
it perforates, the larva nourishes itself with mucus, and lives in 
this state, according to M. Joly, during nearly a whole year. At 
the end of this time if comes out, following the same course by 
which it entered, falls to the ground, and burying itself to the 
depth of a few inches, is transformed into a pupa. The cocoon is 
of a fine black colour. Thirty or forty days after its burial it 
emerges in the perfect state, and detaching the lid at the anterior 
end of the cocoon by the aid of its head, which has increased 
considerably in size, takes flight. 
Notwithstanding the formidable appearance of their trunks, the 
habits of the perfect Conopes (Fig. 
50) are very quiet. In the adult 
state, they are only to be seen on 
flowers, of which they suck the 
honeyed juice. But with their 
larvee the case is otherwise. These 
latter live as parasites on the 
humble-bees (Bomdz). Latreille saw 
the Conops rufipes issue in the 
perfect state from the body of a 
humble-bee, through the intervals of the segments of the abdomen. 
The Muscides form that great tribe of Diptera commonly known 
as Flies, and which are distributed in such abundance over the 
whole world. Faithful companions of plants, the flies follow them 
to the utmost limits of vegetation. At the same time they are 
called upon by nature to hasten the dissolution of dead bodies. 
They place their eggs in the carcasses of animals, and the larvee 
prey upon the corrupt flesh, thus quickly ridding the earth of 
these fatal causes of infection to its inhabitants. The organs of 


Fig. 50.—Conops. 
* “ Recherches sur les (strides en général, et particuliérement sur les Gistres qui 
attaquent homme, le cheval, le boeuf, et le mouton.’”’ Par N. Joly, Professeur a la 
Faculté des Sciences de Toulouse. Lyons, 1846. P. 63. 
