PARASITES. 103 



Such are the Ichneumons, beautiful winged insects, 

 which perfidiously insert their eggs in the body of a 

 living caterpillar, whose internal part serves at the 

 same time for a cradle and for food. The young larva 

 devours organ after organ, beginning with the least im- 

 portant, till the last serves for the formation of the last 

 members of the winged insect. 



More unfortunate are those which are kept under the 

 bolts and bars of their host from their early youth to 

 mature age ; they have no participation in the great 

 banquet of life, except it be in the pleasures of the table 

 and of love. We also find some parasites which occupy 

 different organs in the same animal, and which have 

 different sexual attributes according to the situation 

 which they inhabit. We know some which are herma- 

 phrodite in the rectum or in damp earth, and whose 

 young ones, having the sexes separate, live as parasites 

 in the lungs. 



Parasites are not usually reproductive in the animal 

 which they inhabit. They respect the hearth which 

 shelters them, and their progeny are not developed by 

 their side. The eggs are expelled with the feces, and 

 sown at a distance for other hosts. 



Parasites may be divided into several categories. 

 We may bring together in the first of these, a certain 

 number of animals, which, without being true parasites, 

 seek for a place of shelter, and, either on account of their 

 wretchedness or their misery, require this protection 

 in order that they may live. 



In the second category, we may place those which 

 live at complete liberty, and only require for their sus- 

 tenance the superfluities of their neighbours ; they take 



