196 ROMANCE OF THE INSECT WORLD CHAP. 



base. P. rejecta ofttimes forms a cone-shaped pend- 

 ant nest, which when increased to great extent ends 

 in a long symmetrical cylinder. Other nests are 

 flask-shaped, the base being fastened to the tree ; 

 some are almost globular. The species to whom the 

 last belong, carrying out still farther the principle of 

 enlargement adopted by CJiartergus chartarius and 

 Tatua, build by placing cells not merely upon the 

 outer surface of the layer of cardboard which at the 

 moment constitutes the bottom of the nest, the entire 

 outer wall is covered with cells, when the fresh tier is 

 closed in with a new envelope. Thus a fairly large 

 nest is composed of a whole series of concentric 

 combs, forming hollow spheres set one within the 

 other, not unlike the well-known ivory puzzle balls of 

 the Chinese, the papery ceiling of each comb having 

 been originally the outer wall of the nest. It follows 

 from this arrangement that the direction of the cells 

 is not uniform, as is generally the case with social 

 Hymenoptera. They are neither all placed vertically 

 with their mouths downwards, like those of most 

 wasps, nor are they horizontal, as made by the bee. 

 On the contrary, their bases all point towards the 

 centre of the nest, and all their mouths radiate 

 outwards. The various comb-tiers are generally 

 remarkably close, and pierced with holes for com- 

 munication. 



Very extraordinary are some of the nests be- 

 longing to this genus in the collection of the 

 British Museum the works of Myrapetra scutellaris 

 (see Fig. 33), a mere fanciful title. These huge erec- 

 tions are from Central America, and the native authori- 



