642 



POPULAR SCIENCE MONTHLY. 



size. They nest in hollow trees or in banks or any suitable 

 crevice ; the Trigones, suspend pear-shaped combs from the ex- 

 tremities of the branches of trees, without any kind of external 



covering. Meliponm 

 are masons and prone 

 to block up the gap in 

 the tree they employ 

 with clay, leaving a 

 small orifice for en- 

 trance and exit ; some 

 stop theirs with wax, 

 and they incline to 

 feed on the sweet sap 

 that exudes from the 

 forest trees and on the 

 excrement of birds 

 rather than on flowers. 

 As with the com- 

 munities of social 

 bees, so with the so- 

 cial wasps (Vespidce), 

 there appears a third 

 order of beings, the 

 workers or neuters, 

 which, like the fe- 

 males, are provided 



Fig. 1. Nest of Polistes. A wasp's nest without cover. ... .. m , 



with a sting. The in- 

 terest attached to the economy of the family rivals that of the 

 wonderful works of the hive ; indeed, many of the structures of 

 the social wasps constitute the most beautiful examples of in- 

 sect architecture. Among them there is a variety of form, an 

 evidence of intelligent choice of the materials used in their con- 

 struction, a difference of texture produced, and an adaptation of 

 the nest to the circumstances of the situation to which the build- 

 ings of the bee can lay no claim. If the hive bee is the more ad- 

 mirable architect, it is decidedly not the most ingenious. It is the 

 better mathematician, but the less facile engineer ; it is the more 

 learned, but the less imaginative. While the bees may be said to 

 build in wax, the social wasps are chiefly natural paper or card- 

 board makers not out of rags, but ligneous materials, tritu- 

 rated and agglutinated in various ways. Though the nests are 

 upon many plans, essentially they are all alike. Similar cells, 

 nearly always hexagonal, are agglomerated, leaving between 

 them no space to form combs, after the manner of bees, but of 

 very varying aspects. These are the cradles of the larva?, which, 

 deposited here as eggs, are reared by the female or workers, and, 



