v SOCIAL HOMES 173 



admit the head of the female, who when she gives the 

 inmates mourishment feeds them entirely from the 

 outside. It follows that the wasps bred in them must 

 be of less size than the mother, they are indeed all un- 

 developed females or workers. The cells of the next 

 few tiers are much larger, being the breeding-places 

 of the males and females. Thus, then, workers only 

 are brought forth early in the season ; the males 

 are hatched subsequently, and the virgin females 

 latest of all. The terraces gradually increase in 

 diameter up to the fourth or fifth, when they usually 

 decrease slightly, and in exact conformity with this 

 formation the covering is constructed. They are not 

 perfectly perpendicular but somewhat raised at the 

 corners, so as to form a trifling concavity in the 

 centres of the floors. Though the cells are cup-shaped 

 at their bases, they become beautifully hexagonal as 

 they rise in height, or rather in depth, particularly at 

 the middle of the combs ; a large nest contains from 

 about 7,000 to 10,000. Each is believed to be the 

 birthplace of three generations, with the exception of 

 those intended for the males and females which are 

 probably the cradles of but one brood. Wood fibres 

 seem a flimsy substance of which to make such an 

 edifice, and by which to sustain so great a multitude, 

 but as a fact the walls are very strong, and the 

 hexagonal shape of the cells affords mutual support. 

 Scarce is the building finished ere it begins to show 

 signs of dissolution. The summer is over, the several 

 broods of workers have passed through the cells, and 

 the single generation of males and females have 

 become mature. The males are dead, the workers 



