506 HABITATIONS OF INSECTS. 



sizes, not ranged vertically as in a bee-hive, but hori- 

 zontally, so as to form so many distinct and parallel 

 stories. Each comb is composed of a numerous as- 

 semblage of hexagonal cells formed of the same paper- 

 like substance as the exterior covering of the nest, and, 

 according to a discovery of Dr. Barclay, each, as in those 

 of bees, a distinct cell, the partition walls being double a . 

 These cells, which, as wasps do not store up any food, 

 serve merely as the habitations of their young, are not, 

 like those of the honey-bee, arranged in two opposite 

 layers, but in one only, their entrance being always 

 downwards : consequently the upper part of the comb, 

 composed of the bases of the cells, which are not pyra- 

 midal but slightly convex, forms a nearly level floor, on 

 which the inhabitants can conveniently pass and repass, 

 spaces of about half an inch high being left between each 

 comb. Although the combs are fixed to the sides of the 

 nest, they would not be sufficiently strong without 

 further support. The ingenious builders, therefore, 

 connect each comb to that below it by a number of strong 

 cylindrical columns or pillars, having according to the 

 rules of architecture their base and capital wider than 

 the shaft, and composed of the same paper-like material 

 used in other parts of the nest, but of a more compact 

 substance. The middle combs are connected by a rustic 

 colonnade of from forty to fifty of these pillars ; the up- 

 per and lower combs by a smaller number. 



The cells, which in a populous nest are not fewer than 

 16,000, are of different sizes, corresponding to that of 



a Memoirs of the Werneripn Society, ii. 260, m 



