SOCIAL WASPS AND HORNTAILS 69 



ready to slip out of their larval skin and enter pupahood, 

 when her constructive exertions cease, and the larvae 

 have now to look after themselves. 



Each first spins a convex cap of silk, covering the 

 open end of the cell, and then, in the seclusion of this 

 snug retreat, shielded from the curious gaze of inquisi- 

 tive neighbours, the incipient wasp is " unclothed " and 

 "clothed upon." Not many days elapse before the final 

 change occurs, and, in something under a month from 

 the laying of the egg, the perfect insect is ready to join 

 its mother in her exertions for the enlargement of the 

 home, or rather to relieve her of them. 



So batch after batch of workers is produced, and each, 

 as it arrives at maturity, takes its share in the duties of 

 nest-enlargement and feeding the young. 



When one tier of cells has reached its appointed 

 limits, another is commenced beneath and parallel to it, 

 and connected with the former by sundry tiny pillars of 

 the same papier indche. We note here, therefore, three 

 differences between a wasp's comb and that of bees, viz., 

 first, the combs are made of paper instead of wax ; 

 second, they are placed horizontally instead of vertically ; 

 and, third, the cells are formed only on one side of the 

 comb (the lower) instead of both. The number of insects 

 produced cannot be accurately estimated from the number 

 of cells, because several inmates often successively occupy 

 each. It is manifest, therefore, that the population of 

 the nest, including insects in all stages, is always in 

 excess of the number of cells. 



It is not till quite late in the season that the males 

 and females are produced. They are both larger than 

 the workers, and therefore occupy in their preliminary 

 stages cells of larger dimensions than those mentioned 

 above, and those of the females are placed in a part of 



