HYMENOPTERA. 377 
The exterior envelope of the nest is made with leaves of a sort 
of greyish, very gummy paper, which is applied layer by layer. 
Réaumur has given a very detailed account of the way in which 
these insects construct their nests.* They collect fibres of 
wood, which are their raw material; make them into a sort of 
coarse lint, which they reduce to balls, and carry between their 
lees to the nest. These balls are next stuck on to the work 
already begun. Then the insect stretches them out, flattens them, 
and draws them into thin layers, as a bricklayer spreads mortar 
with his trowel. The wasp works with extreme quickness, always 
backwards, so that it may have incessantly before its eyes the 
work it has done; the movement of its mandibles is even quicker 
than that of its legs. | 
‘owards the end of summer the nest may contain three thousand 
workers, and as many females, who live together in perfect har- 
mony. ‘The number of males equals that of the females. A 
female weighs, by herself, as much as three males, or six workers. 
With the exception of those which are occupied in building 
and in taking care of the eggs, all the wasps go out hunting 
during the day. They are carnivorous, and may be seen attack- 
ing other insects, which they tear to pieces after having killed, 
so as to carry the bits to their nests, where thousands of mouths 
are clamouring for their food. The wasp pays great attention to 
the vines. It penetrates also into the interior of our houses, and 
infests the butchers’ shops; but this the butchers do not much 
mind, for the wasp drives away the flies, which would lay their 
eggs on the meat, and thus contribute to its corruption. 
As the winter approaches, the wasps go out less and less, and 
very soon cease to do so at all. The greater number then die, 
huddled up in their nest. A few females only, as we have said, 
get through the cold season. They sleep with their wings and 
legs folded up, which gives them the appearance of chrysalides. 
They can nevertheless sting in this state, as M. Guerin-Méneville 
found out to his cost. The spring wakes them up, and they then 
found new colonies. “It is at this season,” says M. Maurice 
Girard, in his book on the Metamorphoses of Insects, “that, with 
a little trouble, it would be easy to diminish in a very perceptible 
* “Mémoires,” tome vi., p. 177. 

