14 ARCHITECTURE OF ANTS. 
These halls have a free communica- 
tion by galleries made in the same man- 
ner. If the materials of which the ant- 
hill is composed were only interlaced, 
they would fall into a confused heap 
every time the ants attempted to bring 
them into regular order. This, however, 
is obviated by their tempering the earth 
with rain-water, which afterwards har- 
dening in the sun, so completely and ef- 
fectually bids together the several sub- 
stances as to permit the removal of cer- 
tain fragments from the ant-hill, without 
any injury to the rest: it, moreover, 
strongly opposes the introduction of the 
rain. I never found, even after long and 
violent rains, the interior of the nest 
fly by keeping the aurelia or pupa in a warm room, 
and retarded it by placing it in an ice house. Mr, 
Kirby once kept one of the aphidivorous flies — the 
whole term of whose existence, according to this 
intelligent entomologist, does not, in the summer, 
exceed at the very utmost six weeks — several 
months in the state of larva; and, paradoxical as it 
may seem, by simply neglecting to give it food.—T. 
