68 THE INSECT WOELD. 



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 fur- 

 nished." * 



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 it 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 

 larvae the case is otherwise. These 

 latter live as parasites on the 

 drones. Latreille saw the Conops 

 rufipes issue in the perfect state 



Fig. 50. -Conops. J J r 



from the body of a drone, 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 the dead bodies. 

 In the carcasses of animals they place their eggs, and the larva) 

 prey upon the corrupt flesh, thus quickly ridding the earth of 

 these fatal causes of infection to its inhabitants. The organs of 



* " Recherches sur les CEstrides en general, et particulierement sur les CEstres qui 

 attaquent 1'homme, le cheval, le bceuf, et le mouton." Par N. Joly, Professeur a la 

 Faculte des Sciences de Toulouse. Lyons, 1846. P. 63. 



