HYMENOPTERA. ACULEATA. 219 



how often they have been stung in the course of their 

 lives, and see if the average amount to more than one 

 Wasp sting in thirty years. Secondly, reckoning how 

 many millions of Wasps you may count upon as neigh- 

 hours during those thirty years, calculate how much 

 your chances of being stung are diminished by the 

 number of those that you kill. If after this you still 

 feel that your duty to yourself requires it, then by all 

 means kill the next little nurse or mother that comes to 

 see whether some of your breakfast would be nice for the 

 little ones at home. 



If the common saying that a good plum season is a 

 season of many Wasps be true, we may find in it some 

 comfort under their depredations. 



It is impossible to enter here into the details of the 

 architecture of the Wasp ; suffice it to say that the nest 

 spoken of above consists, when finished, of several large 

 combs, placed horizontally one above the other, with the 

 mouths of the cells downwards, and connected by strong 

 pillars, or rather ligaments of paper, and roofed with a 

 series of layers of grey paper. When, as sometimes 

 happens, the Wasp builds her nest not in the ground but 

 under the roof of an outhouse or loft, the roof is rather 

 differently constructed, and looks like a loose tiling of 

 small oyster-shells. The material with which the nests 

 of the Tree-wasps are made is much tougher than that 

 manufactured by the Ground- wasps, Mr. Smith observ- 

 ing that " the Tree-wasps may be considered as card- 

 board makers, and the Ground-wasps as paper makers." 

 The cells and roofs of the latter are sometimes exceed- 

 ingly fragile, the Wasp using, according to circumstances, 

 decayed or sound wood, but even in this case preferring 

 those parts which are worn by exposure. The oyster- 



