13 
a manner that each sheet barely touches the next, 
instead of being placed so as to form a solid mass. 
In this state, a nest is capable of resisting the heaviest 
rains. In both species the layers of cells in which 
the grubs are deposited are formed of the same ma- 
terials as the outside, and are always placed with 
the opening of the cells downwards, differing in this 
respect from those of the bee, in which the cells are 
always in a horizontal position. Both species too 
commence their work from the top, and build down- 
wards. 
The nest of the tree wasp in its earliest state does 
not exceed an inch in diameter, and contains five or 
six cells only. It is formed of two semicircular 
layers of the paper, the upper one projecting a little 
over the other, so as to shoot off the rain. A hole is 
left at the bottom of it just large enough to admit 
the female wasp. As soon as the first workers quit 
their cells, they begin the task of enlarging the nest, 
and of adding fresh layers of cells in which the fe- 
male immediately deposits more eggs. The nest 
however in all its stages has the appearance of 
being in a finished state externally, and it is pro- 
bably this fact which has given rise to a great many 
mistakes in authors, who from finding nests varying 
in size from one to twelve inches in diameter, have 
been led to describe them as the productions of dis- 
tinct species of wasps, whilst they were in reality 
the work of the Vespa Britannica alone. It some- 
times of course happens, that when the nest is in its 
earliest state, the female wasp is accidentally de- 
stroyed when absent from it. In this case the neu- 
ters forsake their habitation, and by some curious 
instinct the young wasps which emerge from their 
