478 HABITATIONS OF INSECTS. 



greatly increase in size, they find it necessary to en- 

 large. One might fear that a structure formed of such 

 materials would at this period be sadly damaged by the 

 growth of the young shoots and leaves of the twigs 

 which it incloses ; but the inhabitants, as if to guard 

 against such an accident, have gnawed off all the buds 

 within their dwelling, and thus secured themselves 

 from this inconvenience'*. 



The nest of the larvae of another species of moth, the 

 Bomhi/x processioned^ unfortunately not a native of 

 this country, to which on account of their singular 

 manners, that will be detailed to you in a subsequent 

 letter, Reaumur has given the title of processionari/ 

 caterpillars, is somewhat different in its construction 

 from that just described, though formed of the same 

 material. As the caterpillars which fabricate it, feed 

 upon the leaves of the oak, it is always found upon this 

 tree, attached not to the branches but the trunk, some- 

 times at a considerable height from the ground. In 

 shape it resembles an irregular knob or protuberance, 

 and the silk which composes it being of a gray colour, 

 at a distance it would be taken for a mass of lichens. 

 Sometimes this nest is upwards of eighteen inches long, 

 and six broad, rising in the middle about four inches 

 from the surface of the tree. Between the trunk and 

 the silken covering, a single hole is left which serves 

 for the entrance and exit of the inhabitants. These 

 differ in their manners from those last mentioned. 

 While very young they have no fixed habitation, con- 

 tenting themselves with a succession of different tem- 

 porary camps until they have attained two-thirds of 



* Reaum. ii. 128. 



