THE VESP1DAL. 
233 
progeny with sufficient nourishment. The larvae soon become 
full-grown, and spin a silken cocoon, which fills up the little cell, 
and thus enclosed they are transformed into nymphs, the meta- 
morphosis into the adult form occurring shortly. The new wasps 
thus produced are all workers, or rather workeresses, for they are 
sterile females, and they are created to take the part of nurses to 
a progeny which does not belong to them. These workers begin 
their duties as soon as they become perfect, and from that 
moment the mother of the nest, who has been so laborious, and 
who was so industrious when all alone, begins to lead a quiet life, 
and to do little or nothing, for she has plenty of nurses to take 
care of the little ones. The workers increase the extent of the 
nest, and prepare cells for the larvae, and, when this is done, the 
mother completes another great batch of egg-laying, and deposits 
an egg in each cell. The larvae which come from these eggs . do 
not turn into workers only, but into male insects and females 
which are not sterile. It is not known how many egg-layings 
take place during the year, but they probably vary with the 
species. Very often the combs of the nests are found to con- 
tain larvae late in the season, and when cold weather suddenly 
sets in. In this case the wasps appear to understand that the 
fruits will soon be all gone, and that the means of subsistence 
will be cut off ; but, in order that the larvae shall not suffer from 
prolonged starvation, these intelligent creatures kill them at once, 
so that the nest which was a few days before full of life, activity, 
and animation, becomes a dreary solitude. The wasps construct 
their nests out of vegetable matters, such as woody fibres and dead 
leaves, and they make a sort of paper from these substances. 
They triturate their building materials between their mandibles, 
moisten them with their saliva, and mould them into a homo- 
geneous paste, admirably suited for the construction of the cells 
and the walls of the nests. The nests are made upon different 
plans, all of which appear to have a distinct reference to some 
peculiar conformation of the insect. But, although there are many 
minor differences, still, in the main, all wasps’ nests resemble each 
other. The essential and most important parts of the nests are 
the cells of the comb, and they are always built upon the same 
plan. In the commencement the cell is a kind of cylindrical cup, 
