se their skin and become as smooth as though we had held
them on a grindstone. After a whole afternoon of this work, our back
will be aching, our fingers will be itching and smarting and we shall
possess a dozen Osmia-nests and perhaps two or three Resin-bees' nests.
Let us be content with that.

The Osmia's shells can be recognized at once, as being closed at
the orifice with a clay cover. The Anthidium's call for a special
examination, without which we should run a great risk of filling our
pockets with cumbersome rubbish. We find a dead Snail-shell among the
stones. Is it inhabited by the Resin-bee or not? The outside tells us
nothing. The Anthidium's work comes at the bottom of the spiral, a long
way from the mouth; and, though this is wide open, the eye cannot travel
far enough along the winding stair. I hold up the doubtful shell to the
light. If it is completely transparent, I know that it is empty and I
put it back to serve for future nests. If the second whorl is opaque,
the spiral contains something. What does it contain? Earth washed in by
the rain? Remnants of the putrefied Snail? That remains to be seen.
With a little pocket-trowel, the inquisitorial implement which always
accompanies me, I make a wide window in the middle of the final whorl.
If I see a gleaming resin floor, with incrustations of gravel, the
thing is settled: I possess an Anthidium's nest. But, oh the number of
failures that go to one success! The number of windows vainly opened in
shells whose bottom is stuffed with clay or with noisome corpses! Thus
picking shells among the overturned stone-heaps, inspecting them in
the sun, breaking into them with the trowel and nearly always rejecting
them, I manage, after repeated attempts, to obtain my materials for this
chapter.

The first to hatch is the Seven-pronged Resin-bee (Anthidium
septemdentatum). We see her, in the month of April, lumbering along to
the rubbish-heaps in the quarries and the low boundary-walls, in search
of her Snail-shell. She is a contemporary of the Three-horned Osmia, who
begins operations in the last week of April, and often occupies the same
stone-heap, settling in the next shell. She is well-advised to start
work early and to be on neighbourly terms with the Osmia when the latter
is building; in fact, we shall soon see the terrible dangers to which
that same proximity exposes her dilatory rival in resin-work, Anthidium
bellicosum.

The shell adopted in the great ma