Next comes the ration of honey, the laying of the egg and the
partitioning, the last a delicate operation to which the insect
proceeds by degrees from the base to the top. At the bottom of the
gallery, a pile of honey is placed and an egg laid upon the pile;
then a partition is built to separate this cell from the next, for
each larva must have its special chamber, about a centimetre and a
half (.58 inch.--Translator's Note.) long, having no communication
with the chambers adjoining. The materials employed for this
partition are bramble-sawdust, glued into a paste with the insects'
saliva. Whence are these materials obtained? Does the Osmia go
outside, to gather on the ground the rubbish which she flung out when
boring the cylinder? On the contrary, she is frugal of her time and
has better things to do than to pick up the scattered particles from
the soil. The channel, as I said, is at first uniform in size, almost
cylindrical; its sides still retain a thin coating of pith, forming
the reserves which the Osmia, as a provident builder, has economized
wherewith to construct the partitions. So she scrapes away with her
mandibles, keeping within a certain radius, a radius that corresponds
with the dimensions of the cell which she is going to build next;
moreover, she conducts her work in such a way as to hollow out more
in the middle and leave the two ends contracted. In this manner, the
cylindrical channel of the start is succeeded, in the worked portion,
by an ovoid cavity flattened at both ends, a space resembling a
little barrel. This space will form the second cell.

As for the rubbish, it is utilized on the spot for the lid or cover
that serves as a ceiling for one cell and a floor for the next. Our
own master-builders could not contrive more successfully to make the
best use of their labourers' time. On the floor thus obtained, a