ENEMIES OF THE CATERPILLAR. 81 



the butterfly, yet often falls a prey to the ichneu- 

 mon, who pursues the robber to his retreat, and, 

 despising his nets, tears him in pieces, in the 

 very labyrinth he has made. This insect, as re- 

 doubtable as the little quadruped that destroys 

 the crocodile, has received the same name ; and 

 from its destruction of the caterpillar tribe, is 

 probably more serviceable to mankind: This 

 insect, I say, makes the body of the caterpillar 

 the place for depositing its eggs, to the number 

 of ten, fifteen, or twenty. As they are laid in 

 those parts which are not mortal, the reptile still 

 continues to live and to feed, showing no signs 

 of being incommoded by its new guests. The 

 caterpillar changes its skin, and sometimes under- 

 goes the great change into an aurelia ; but still 

 the fatal intruders work within, and secretly de- 

 vour its internal substance : soon after, they are 

 seen bursting through its skin, and moving away, 

 in order to spin themselves a covering previous 

 to their own little transformation. It is indeed 

 astonishing sometimes to see the number of 

 worms, and those pretty large, that thus issue 

 from the body of a single caterpillar, and eat 

 their way through its skin ; but it is more extra- 

 ordinary still, that they should remain within the 

 body, devouring its entrails, without destroying 

 its life. The truth is, they seem instructed by 

 nature not to devour its vital parts ; for they are 

 found to feed only upon that fatty substance 

 which composes the largest part of the caterpil- 

 lar's body. When this surprising appearance was 

 first observed, it was supposed that the animal 

 VOL. vi. F 



