502 HABITATIONS OF INSECTS. 



this external coverinfr, we perceive that the interior con- 

 sists of from twelve to fifteen circular combs of different 

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

 zontally, so as to form so many distinct and parallel sto- 

 ries. Each comb is composed of a numerous assem- 

 blage of hexagonal cells formed of the same paper-like 

 substance as the exterior covering of the nest, and ac- 

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

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

 These cells, which, as wasps do not stoi'e 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 tlie combs are fixed to the sides 

 of the nest, they would not be sufficiently strong without 

 'further support. Tlie ingenious builders, therefore, con- 

 nect 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 



'' Memoirs of the Wcrncrian Suciety, ii. 260. 



