an in
one of these colossal cities, an estate which is constantly increasing
as it passes down from one generation to another; nowhere does it find a
better workshop for the exercise of its industry. Here it has plenty of
room: a quiet resting-place, sheltered from damp and from excess of heat
or cold.

But the spacious domain under the tiles is not within the reach of all:
sheds with free access and the proper sunny aspect are pretty rare.
These sites fall only to the favoured of fortune. Where will the others
take up their quarters? More or less everywhere. Without leaving the
house in which I live, I can enumerate stone, wood, glass, metal, paint
and mortar as forming the foundation of the nests. The green-house with
its furnace heat in the summer and its bright light, equalling that
outside, is fairly well-frequented. The Mason-bee hardly ever fails to
build there each year, in squads of a few dozen apiece, now on the glass
panes, now on the iron bars of the framework. Other little swarms settle
in the window embrasures, under the projecting ledge of the front door
or in the cranny between the wall and an open shutter. Others again,
being perhaps of a morose disposition, flee society and prefer to work
in solitude, one in the inside of a lock or of a pipe intended to carry
the rain-water from the leads; another in the mouldings of the doors and
windows or in the crude ornamentation of the stone-work. In short,
the house is made use of all round, provided that the shelter be an
out-of-door one; for observe that the enterprising invader, unlike
the Pelopaeus, never penetrates inside our dwellings. The case of
the conservatory is an exception more apparent than real: the glass
building, standing wide open throughout the summer, is to the Mason-bee
but a shed a little lighter than the others. There is nothing here to
arouse the distrust with which anything indoors or shut up inspires
her. To build on the threshold of an outer door, or to usurp its lock,
a hiding-place to her fancy, is all that she allows herself; to go any
farther is an adventure repugnant to her taste.

Lastly, in the case of all these dwellings, the Mason-bee is man's free
tenant; her industry makes use of the products of our own industry. Can
she have no other establishments? She has, beyond a doubt; she possesses
some constructed on the ancient plan. On a stone the size of a man's
fist, protected by the shelter of a hedge, sometimes even on a pebbl