4a6 THEPHILOSOPHY 



to contain the whole. According as the animals increafe in fize, the 

 number of their tents is augmented. But ihefe are only temporary 

 and partial lodgements, conftruded for mutual conveniency, till the 

 caterpillars are in a condition to build one more fpacious, and which 

 will be fufficient to contain the whole. After gnawing one half of 

 the fubftance of fuch leaves as happen to be near the end of fome 

 twig or fmall branch, they begin their great work. In conftruding 

 this new edifice or neft, the caterpillars encruft a confiderable part 

 of the twig with white filk. In the fame manner, they cover two 

 or three of fuch leaves as are neareft to the termination of the twig. 

 They then fpin filken coverings of greater dimenfions, in which they 

 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 employed in the common labour. Thefe 

 nefts are too frequently feen, in autumn, upon the fruit-trees of our 

 gardens. They are ftill more expofed to obfervation in winter, 

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

 They confift of large bundles of white filk and withered leaves, with- 

 out any regular or conftant form. Some of them are flat, and others 

 roundifh; 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 internal part of the neft is divided intaa n^umber of 

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

 be very irregular, there are paflages by which the caterpillars can ei- 

 ther go out in queft of food, or retire in the evening, or during rainy 

 weather. The filken coverings, by repeated layers, become at laft fo 

 thick and ftrong, that they refift all the attacks of the wind, and all 

 the injuries of the air, during eight or nine months. About the be- 

 ginning of October, or when the froft firft commences, the whole 

 community fliut themfelves up in the neft. During the winter 

 they remain immoveable, and feemingly dead. But, when expofed 

 10 hear, they foon difcover fymptoms of life, and begin to creep. In 



this 



