OF NATURAL HISTORY. 385 



thing but the head, feet, and empty {kins. In a few days, one only 

 of the twenty remained in life. 



Caterpillars have myriads of external enemies, as birds of almoft 

 every kind, many of the fmaller quadrupeds, their own fpecies, and 

 numberlefs infeds. But this vaft fource of devaftation is ftill aug- 

 mented by what may be denominated their internal enemies. Many 

 flies depofit their eggs in the bodies of caterpillars. From thefe eggs 

 proceed fmall maggots, which gradually devour the vitals of the 

 animal in which they refide. When about to be transformed into 

 chryfalids, they pierce the fkin of the caterpillar, fpin their pods, 

 and remain on the empty fkin till they aflurae the form of flies, and 

 efcape into the air to perform the fame cruel office to another un- 

 fortunate reptile. Every perfon muft recoiled: to have feen the 

 colewort or cabbage caterpillar ftuck upon old walls, or the win- 

 dows of country cottages, totally covered with thefe chryfalids, which 

 have the form of fmall maggots, and are of a fine yellow colour. 

 One of the moft formidable enemies of the caterpillar is a black 

 worm, with fix cruftaceous legs. It is as long, and thicker than 

 an ordinary fized caterpillar. In the fore part of the head it has two 

 curved pincers, with which it quickly pierces the belly of a cater- 

 pillar, and never quits the prey till it is entirely devoured. The 

 largeft caterpillar is not fufficient to nourifh this worm for a fingle 

 day ; for it daily kills and eats feveral of them. Thefe gluttonous 

 worms, when gorged vv^ith food, become inadive, and almoft mo- 

 tionlefs. When in this fatlated condition, young worms of the fame 

 fpecies attack and devour them. Of all trees, the oak, perhaps, nou- 

 rifhes the greateft number of different caterpillars, as well as of dif- 

 ferent infers. Amongft others, the oak is inhabited by a large and 

 beautiful beetle. This beetle frequents the oak, probably becaufe 

 that tree is inhabited by the greateft number of caterpillars. It 



3 G f marches 



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