OF NATURAL HiSTORy. 431 



nlency, thefe dlfguftlng reptiles know how to enlarge both 

 the nefl and its pafFages by additional operations accommo- 

 dated to their prefent ftate. Into thefe new lodgings they 

 retire when they want to repofe, to fcreen themfelves from 

 the injuries of the weather, or to caft their fls:ins. In fine, 

 after cafting their ikins feveral times, the time of their dif- 

 perfion arrives. From the beginning to near the end of 

 June, they lead a folitary life. Their focial difpofition is no 

 longer felt. Each of them fpins a pod of coarfe brown- 

 ifli filk. In a few days they are changed into chryfalids y 

 and, in eighteen or twenty days more, they are transformed 

 into butterflies. 



Caterpillars of another fpecies, which Reaumur dlftlnguifh- 

 es by the appellation of the procejfwnar^ caterpillar^ live in fo- 

 ciety till their transformation into flies. Thefe caterpillars 

 are of the hairy kind, and are of a reddifh colour. They in- 

 habit the oak, and feed upon its leaves. AVhen very young, 

 they have no fixed or general habitation. But, after they 

 have acquired about one half of their natural fize, they af- 

 femble to<Tethcr, and conftruft a neft fufUcieat to accomm.o- 

 date the whole. The nefts of thefe caterpilhrs are attached 

 to the trunks of the oak, and are fituated fometimes near the 

 earth, and fometimes feven or eight f^et above its furface. They 

 confift of difl'erent'flrata, or layers, of filk, which are fpun 

 by the united labour of the whole community. Their figure js 

 neither Rriking nor uniform. On the part of the oak to which 

 they are fixed they form a protuberance fimilarto thofe knots 

 which are feen upon trees. This protuberance fometimes 

 refembles a fegment of a circle, and fometimes it is three or 

 four times longer than it is broad. Some of thefe nefts are 

 from eighteen to twenty inches long, and from five to fix 

 inches wide. About the middle of their convexity, they of- 

 ten rife more than four inches above the furface of the tree. 



