430 THE PHILOSOPHY 



the caterpillars encrufl a confiderable part of the twig with 

 white fiik. In the faaie manner, they cover two or three of 

 fuch leaves as are nearefl to the termination of the twig. 

 They then fpin filken coverings of greater dimenfions, in 

 which rhey inclofe the two or three leaves together with the 

 twig. The neft is now fo fpacious that it is able to contain 

 the whole community, every individual of which is employ- 

 ed in the common labour. Thefe nefts are too frequently 

 feen, in autumn, upon the fruit-trees of our gardens. They 

 are ftill more expolied to obfervation in winter, when the 

 leaves, which formerly concealed many of them, are fallen. 

 They confift of large bundles of white filk and wither- 

 ed leaM'es, without any regular or conftant form. Some of 

 them are flat, and others roundifli ; but none of them are 

 deftitute of angles. By different plain coverings extended 

 from the oppofite fides of the leaves and of the twig, the in- 

 ternal part of the neil: is divided into a number of different 

 apartments. To each of thefe apartments, which feem to be 

 very irregular, there are paflages by which the caterpillars 

 can either go out in queft of food, or retire in the evening, 

 or during rainy weather. The filken coverings, by repeated 

 layers, become at laft {o thick and flrong, that they refift all 

 the attacks of the wind, and all the injuries of the air, dur- 

 ing eight or nine months. About the beginning of Odlober, 

 or when the froft firft commences, the whole community fhut 

 themfelves up hi the nefl:. During the winter they remain 

 inimoveable, and feemingly dead. But, when expofed to 

 heat, they foon difcover lymptoms of life, and begin to creep. 

 In this country, they feldom go out of the neil till the mid- 

 dle or end of April. Vf hen they ILut themfelves up for the 

 winter, they are very fmail ; but, after they have fed for 

 fome days in fpring upon the young and tender leaves, they 

 fmd the neft itfelf, and all the entrances to it, too fmall for 

 the iucreafed fize of their bodies. To remedy this inconve- 



