190 NATURAL HISTORY OF WASPS. 
bottom of the nest should be kept constantly closed, 
and labour as well as material is abundant, it is 
applied unsparingly. As the comb grows, day by 
day, still wider and wider, the inside of the case is 
cut away to make room for it; and the paper which 
is removed on the inside is replaced by new layers on 
the outer surface. So that all the space enclosed in 
a wasp’s nest is occupied twice, first by layers of 
paper in the gradual expansion of the case, and ulti- 
mately by comb. The quantity of material con- 
sumed in the construction of a large nest must be 
very great, for, as a rule, the waste cuttings are not 
employed again. To a certain extent the paper 
which has been used once may be again available, as 
a source of material; but it is never transferred from 
one part of the structure to another without being 
nibbled down and worked up into pulp, as in the 
first instance. The floor under a swarm of working 
wasps is strewed with scraps of waste paper, as 
thickly as the floor of a bee-hive is with waste wax 
plates. Not unfrequently wasps will avail them- 
selves of neighbouring leaves to work into their 
nests, and some foreign genera* make the cover of 
their nest of a large leaf. But wasp-paper is never 
removed and re-applied in bulk, any more than the 
material of which bees make their cells. 
We must not measure the proceedings of wasps 
by the same rule which we apply to a man with a 
taste for building, who gradually expands a cottage, 
at the cost of much useless labour, and with great 
* Polybia sedula, figured by De Saussure. ‘ Guépes Sociales,’ 
Pl. XXI. Leipomeles lamellaria, Mobius. ‘Die Nester der Gesel- 
ligen Wespen.’ Taf. XVII, und anders. 4to. Hamburg. 1856. 
