SPINNING CATERPILLARS. 331 



This irregularity arises from the circumstance of 

 each individual acting on its own account, without 

 the direction or superintendence of the others. The 

 interior of the structure is, for the same reason, 

 more regular, being divided into compartments, each 

 of which forms a chamber for one or more indi- 

 viduals. Previous to the cold weather these cham- 

 bers have but slight partitions ; but before the frosts 

 set in the whole is made thick and warm. 



Winter nests of Porthesia chrysorrhan, one being cut open to show 

 the chamber!. The dots represent the egesta of the caterpillars. 



A no less remarkable winter nest, of a small spe- 

 cies of social caterpillar, is described by M. Bonnet, 

 vhich we omitted to introduce when treating of the 

 Glanville fritillary (page 172). The nest in question 

 is literally pendulous, being hung from the branch of 

 a fruit-tree by a strong silken thread. It consists of 

 one or two leaves neatly folded, and held together 



