CATERPILLARS. 173 



the most part, approaches the pyramidal, though that 

 depends much upon the natural growth of the her- 

 bage which composes it. The interior is divided into 

 compartments formed by the union of several small 

 tents, as it were, to which others have been from time 

 to time added according to the necessities of the com- 

 munity. 



When they have devoured all the leaves, or at 

 least those which are most tender and succulent, 

 they abandon their first camp, and construct another 

 contiguous to it under a tuft of fresh leaves. Several 

 of these encampments may sometimes be seen within 

 the distance of a foot or two, when they can find 

 plantain (Plantago lanceolata) fit for their purpose ; 

 but though they prefer this plant, they content them- 

 selves with grass if it is not to be procured. 



When they are about to cast their skins, but par- 

 ticularly when they perceive the approach of winter, 

 they construct a more durable apartment in the inte- 

 rior of their principal tent. The ordinary web is 

 thin and semi-transparent, permitting the leaves to 

 be seen through it ; but their winter canvass, if we 

 may call it so, is thick, strong, and quite opaque, 

 forming a sort of circular hall without any partition, 

 where the whole community lie coiled up and huddled 

 together. 



Early in spring they issue forth in search of fresh 

 food, and again construct tents to protect them from 

 cold and rain, and from the mid-day sun. 



M. Reaumur found upon trial, that it was not only 

 the caterpillars hatched from the eggs of the same 

 mother which would unite in constructing the com- 

 mon tent ; for different broods, when put together, 

 worked in the same social and harmonious manner. 

 We ourselves ascertained, during the present sum- 

 mer (1829), that this principle of sociality is not 

 confined to the same species, nor even to the same 



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