them to the village inn on Sunday.
A reward in ready money is promised for each nest that fulfils the
desired conditions; and the bargain is enthusiastically accepted.

There are three of them; and I make a fourth. Shall we manage it, among
us all? I thought so. By the end of August, however, my last illusions
were dispelled. Not one of us had succeeded in seeing the big black Fly
perching on the dome of the mason bee.

Our failure, it seems to me, can be explained thus: outside the spacious
front of the Anthophora's settlement, the Anthrax is in permanent
residence. She visits, on the wing, every nook and corner, without
moving away from the native cliff, because it would be useless to go
farther. There is board and lodging here, indefinitely, for all her
family. When some spot is deemed favorable, she hovers round inspecting
it, then comes up suddenly and strikes it with the tip of her abdomen.
The thing is done, the egg is laid. So I picture it, at least. Within a
radius of a few yards and in a flight broken by short intervals of rest
in the sun, she carries on her search of likely places for the laying
and dissemination of her eggs. The insect's assiduous attendance upon
the same slope is caused by the inexhaustible wealth of the locality
exploited.

The Anthrax of the Chalicodoma labors under very different conditions.
Stay-at-home habits would be detrimental to her. With her rushing
flight, made easy by the long and powerful spread of her wings, she must
travel far and wide if she would found a colony. The bee's nests are not
discovered in groups, but occur singly on their pebbles, scattered more
or less everywhere over acres of ground. To find a single one is not
enough for the fly: on account of the many parasites, not all the cells,
by a long way, contain the desired larva; others, too well protected,
would not allow of access to the provisions. Very many nests are
necessary, perhaps, for the eggs of one alone; and the finding of them
calls for long journeys.

I therefore picture the Anthrax coming and going in every direction
across the stony plain. Her practiced eye requires no slackened flight
to distinguish the earthen dome which she is seeking. Having found it,
she inspects it from above, still on the wing; she taps it once and
yet once again with the tip of her ovipositor and forthwith makes off,
without having set foot on the ground. Should she take a rest, it will
be elsewhere, no matter where, on