54 



NATURAL HISTORY. [CH. III. 



like a honeycomb, the thickness of the layer being 

 equal to the length of the cocoon, and its extent 



Fig. 1. 



equal to the size of the nest ; but it generally hap- 

 pens that the latter is not sufficiently large to allow 

 all the cocoons to be arranged in a single tier, so 



Fig. 2. 



that sometimes they consist of two, and occasion- 

 ally of three layers. After the whole of the moths 

 have been produced (all of which make their ap- 

 pearance in the same day), these layers of cocoons 

 very much resemble the combs of a bee or a wasp's 

 nest, the head of each cocoon being stripped off by 



