244 SOCIETY OF ANIMALS. 



What are called the common caterpillars afford an instance 

 of proper association. About the middle of summer, a but- 

 terfly deposits from three to four hundred eggs on the leaf of 

 a tree, from each of which, in a few days, a young caterpillar 

 proceeds. They are no sooner hatched than they begin to 

 form a common habitation. They spin silken threads, which 

 they attach to one edge of the leaf, and extend them to the 

 other. By this operation they make the two edges of the 

 leaf approach each other, and form a cavity resembling a 

 hammock. In a short time, the concave leaf is completely 

 roofed with a covering of silk. Under this tent the animals 

 live together in mutual friendship and harmony. When not 

 disposed to eat or spin, they retire to their tent. It requires 

 several of these habitations to contain the whole. According 

 as these animals increase in size, the number of their tents is 

 augmented. But these are only temporary and partial lodg- 

 ments, constructed for mutual conveniency, till the caterpil- 

 lars are in a state to build one more spacious, and which will 

 be sufficient to contain the whole. After gnawing one half 

 of the substance of such leaves as happen to be near the end 

 of some twig or small branch, they begin their great work. 

 In constructing this new edifice or nest, the caterpillars en- 

 crust a considerable part of the twig with white silk. In the 

 same manner, they cover two or three of such leaves as are 

 nearest to the termination of the twig. They then spin silken 

 coverings of greater dimensions, in which they inclose the 

 two or three leaves together with the twig. The nest is now 

 so spacious that it is able to contain the whole community, 

 every individual of which is employed in the common labor. 

 These nests are too frequently seen, in autumn, upon the 

 fruit-trees of our gardens. They are still more exposed to 

 observation in winter, when the leaves, which formerly con- 

 cealed many of them, have fallen. They consist of large 

 bundles of white silk and withered leaves, without any reg- 

 ular or constant form. Some of them are flat, and others 

 roundish ; but none of them are destitute of angles. By dif- 

 ferent plain coverings extended from the opposite sides of 

 the leaves and of the twig, the internal part of the nest is 

 divided into a number of different apartments. To each of 

 these apartments, which seem to be very irregular, there are 

 passages by which the caterpillars can either go out in quest 

 of food, or retire in the evening, or during rainy weather. 

 The silken coverings, by repeated layers, become at last so 

 thick and strong, that they resist all the attacks of the wind, 



