ENEMIES OF TH CATERPILLAR. 79 



the human species only are found to destroy each 

 other, has been adopted by persons who never 

 considered the history of insects. Some of the 

 caterpillar kind in particular, that seem fitted 

 only to live upon leaves and plants, will, how- 

 ever, eat each other ; and the strongest will de- 

 vour the weak, in preference to their vegetable 

 food. That which lives upon the oak is found 

 to seize any of its companions which it conve- 

 niently can, by the first rings, and inflict a deadly 

 wound j it then feasts in tranquillity on its prey, 

 and leaves nothing of the animal but the husk. 



But it is not from each other they have the 

 most to fear, as in general they are inoffensive, 

 and many of this tribe are found to live in a kind 

 of society. Many kind of flies lay their eggs 

 either upon or within their bodies, and as these 

 turn into worms, the caterpillar is seen to nourish 

 a set of intestine enemies within its body that 

 must shortly be its destruction ; nature having 

 taught flies, as well as all other animals, the 

 surest methods of perpetuating their kind. " To- 

 wards the end of August," says Reaumur, " I 

 perceived a little fly, of a beautiful gold colour, 

 busily employed in the body of a large caterpillar, 

 of that kind which feeds upon cabbage. I gently 

 separated that part of the leaf on which these in- 

 sects were placed from the rest of the plant, and 

 placed it where I might observe them more at my 

 ease. The fly, wholly taken up by the business 

 in which it was employed, walked along the 

 caterpillar's body, now and then remaining fixed 

 to a particular spot. Upon this occasion I per- 



