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Insect Architecture. 



arrangement, though still of the pensile character. One 

 species builds a nearly globular nest, made in a rather curious 

 manner. Carrying out still farther the principle on which 



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Nests of Polybia. 



the cardboard wasp enlarges its nest, the Polybia entirely 

 covers the outer wall with cells, and then makes a new wall 

 over them. When a nest has reached a tolerable size, it is 

 composed of a whole series of concentric combs, the roof of 

 each having been originally the outer wall of the nest. 

 There are in the British Museum some admirable specimens 

 of these nests, in some of which the process of enlargement 

 can be very clearly traced. Patches of new cells are seen upon 

 the external covering, while a few breaches in the structure 

 show the concentric combs. 



One very curious point about these cells is, that they are 

 not uniform in their direction, as is generally the case with 



