een putty with which she builds
her partitions and finally closes the entrance to the dwelling. When
she settles in the spacious cells of the Masked Anthophora (Anthophora
personata, ILLIG.), the entrance to the gallery, which is wide enough to
admit one's finger, is closed with a voluminous plug of this vegetable
paste. On the earthy banks, hardened by the sun, the home is then
betrayed by the gaudy colour of the lid. It is as though the authorities
had closed the door and affixed to it their great seals of green wax.

So far then as their building-materials are concerned, the Osmiae whom
I have been able to observe are divided into two classes: one building
compartments with mud, the other with a green-tinted vegetable putty.
The first section includes the Horned Osmia and the Three-horned Osmia,
both so remarkable for the horny tubercles on their faces.

The great reed of the south, the Arundo donax, is often used, in the
country, for rough garden-shelters against the mistral or just for
fences. These reeds, the ends of which are chopped off to make them all
the same length, are planted perpendicularly in the earth. I have often
explored them in the hope of finding Osmia-nests. My search has very
seldom succeeded. The failure is easily explained. The partitions and
the closing-plug of the Horned and of the Three-horned Osmia are made,
as we have seen, of a sort of mud which water instantly reduces to pap.
With the upright position of the reeds, the stopper of the opening would
receive the rain and would become diluted; the ceilings of the storeys
would fall in and the family would perish by drowning. Therefore the
Osmia, who knew of these drawbacks before I did, refuses the reeds when
they are placed perpendicularly.

The same reed is used for a second purpose. We make canisses of it,
that is to say, hurdles, which, in spring, serve for the rearing of
silk-worms and, in autumn, for the drying of figs. At the end of April
and during May, which is the time when the Osmiae work, the canisses
are indoors, in the silk-worm nurseries, where the Bee cannot take
possession of them; in autumn, they are outside, exposing their layers
of figs and peeled peaches to the sun; but by that time the Osmiae have
long disappeared. If, however, during the spring, an old, disused hurdle
is left out of doors, in a horizontal position, the Three-horned Osmia
often takes possession of it and makes use of the two ends, where the
reeds lie