SOCIAL ECONOMY. 253 
the tree- or of the ground-nests. But where the 
ground is stony, the entrance is marked by a heap 
of pebbles, which the wasps have pushed up from 
beneath thus far, but could not fly away with. 
I have met with an illustration of this which is 
worth recording :—The entrance to a very strong 
nest of V. vulgaris was encumbered with a heap of 
such little pebbles. On an average, each of these 
weighed 1°85 grains. They were all of very nearly 
the same weight, so uniformly, indeed, that it seemed 
as if no stone heavier than two grains could be got 
out of the hole, and all lighter than one grain could 
be carried away to a distance. When I returned to 
the nest some weeks after, this conclusion was con- 
firmed by finding the larger pebbles forming a bed 
of gravel at the bottom of the den. Each of the 
stones at the pit’s mouth seemed to represent the 
power of a single wasp; for wasps, unlike ants, 
labour singly; so the stones which one wasp cannot 
lift lie at the bottom of the nest, and the snails, 
which one wasp or bee cannot drag out are papered 
or waxed up when they die. Though a little com- 
bined exertion, such as ants or beetles would have 
applied, would have effectually removed the nuisance 
from their doors. 
An ant or a burying-beetle would have solved 
this problem. Another, as Mr. Prince, of Uckfield, 
has reported it to me, would probably have sur- 
passed even their ingenuity. A butcher often re- 
venged himself on the wasps which stole his meat 
by clipping their wings. Long practice, with a sharp 
pair of scissors, had made him so dexterous that he 
could snip off a wing without interrupting the wasp 
