etimes
winding, nearly horizontal, polished with minute care and varnished with
a sort of white glaze. It looks as if it had received a thin coat of
whitewash. On the inner surface of this passage, in the thickness of
the earthy bank, spacious oval niches have been excavated, communicating
with the corridor by means of a narrow bottle-neck, which is closed,
when the work is done, with a substantial mortar stopper. The Anthophora
polishes the outside of this stopper so well, smooths its surface so
perfectly, bringing it to the same level as that of the passage, is so
careful to give it the white tint of the rest of the wall that, when
the job is finished, it becomes absolutely impossible to distinguish the
entrance-door corresponding with each cell.

The cell is an oval cavity dug in the earthy mass. The wall has the
same polish, the same chalky whiteness as the general passage. But the
Anthophora does not limit herself to digging oval niches: to make her
work more solid, she pours over the walls of the chamber a salivary
liquid which not only whitens and varnishes but also penetrates to a
depth of some millimetres into the sandy earth, which it turns into
a hard cement. A similar precaution is taken with the passage; and
therefore the whole is a solid piece of work capable of remaining in
excellent condition for years.

Moreover, thanks to the wall hardened by the salivary fluid, the
structure can be removed from its matrix by chipping it carefully away.
We thus obtain, at least in fragments, a serpentine tube from which
hangs a single or double row of oval nodules that look like large grapes
drawn out lengthwise. Each of these nodules is a cell, the entrance to
which, carefully hidden, opens into the tube or passage. When she wishes
to leave her cell, in the spring, the Anthophora destroys the mortar
disk that closes the jar and thus reaches the general corridor, which
is quite open to the outer air. The abandoned nest provides a series of
pear-shaped cavities, of which the distended part is the old cell and
the contracted part the exit-neck, rid of its stopper.

These pear-shaped hollows form splendid lodgings, impregnable
strongholds, in which the Osmiae find a safe and commodious retreat for
their families. The Horned Osmia and the Three-horned Osmia establish
themselves there at the same time. Although it is a little too large for
her, Latrielle's Osmia also appears very well satisfied with it.

I have examined