Most of these insects have been submitted to a learned expert,
Professor Jean Perez, of Bordeaux. I take this opportunity of
renewing my thanks for his kindness in identifying them for me.--
Author's Note.)

They include members of very diverse corporations. Some, more
industrious and equipped with better tools, remove the pith from the
dry stem and thus obtain a vertical cylindrical gallery, the length
of which may be nearly a cubit. This sheath is next divided, by
partitions, into more or less numerous storeys, each of which forms
the cell of a larva. Others, less well-endowed with strength and
implements, avail themselves of the old galleries of other insects,
galleries that have been abandoned after serving as a home for their
builder's family. Their only work is to make some slight repairs in
the ruined tenement, to clear the channel of its lumber, such as the
remains of cocoons and the litter of shattered ceilings, and lastly
to build new partitions, either with a plaster made of clay or with a
concrete formed of pith-scrapings cemented with a drop of saliva.

You can tell these borrowed dwellings by the unequal size of the
storeys. When the worker has herself bored the channel, she
economizes her space: she knows how costly it is. The cells, in that
case, are all alike, the proper size for the tenant, neither too
large nor too small. In this box, which has cost weeks of labour, the
insect has to house the largest possible number of larvae, while
allotting the necessary amount of room to each. Method in the
superposition of the floors and economy of space are here the
absolute rule.

But there is evidence of waste when the insect makes use of a bramble