268 NATURAL HISTORY. [CH. XVI. 



to prevent them from growing in the spring : they 

 thus secure their abode from the destruction which 

 would ensue from the sprouting of the branches. 

 They then enclose, in a double covering of silk, one 

 or two leaves at the end of the shoot ; these leaves 

 being thus brought together are worked into the 

 form of a vault : the nest of these caterpillars may 

 very commonly be observed attached to our fruit- 

 trees in the autumn, when the fall of the leaves dis- 

 closes them to view. By an inexperienced eye one 

 of these nests might be mistaken for the web of a 

 spider: indeed, when deserted by the caterpillars, 

 they not unfrequently become the abode of this in- 

 sect. These nests vary in shape ; some being round, 

 others flat. 



They differ also in extent : in proportion also as 

 they become enlarged, either in length, breadth, or 

 capacity, a greater number of leaves, little shoots, 

 and even branches, are comprised within the limits 

 of the tent. The irregularity of their shape arises 

 from the additional webs which, from time to time, 

 it becomes necessary to form. These additional webs 

 divide the interior of the nest into regular compart- 

 ments ; each of them capable of containing a number 



