the banks
inhabited by the Anthophora. At this period all is silent near the
nests; the work has long been completed; and numbers of Spiders' webs
line the crevices or plunge their silken tubes into the Bee's
corridors. Let us not, however, hastily abandon the city once so
populous, so full of life and bustle and now deserted. A few inches
below the surface, thousands of larvae and nymphs, imprisoned in their
cells of clay, are resting until the coming spring. Might not such a
succulent prey as these larvae, paralysed and incapable of defence,
tempt certain parasites who are industrious enough to attain them?

Here indeed are some Flies clad in a dismal livery, half-black,
half-white, a species of Anthrax (_A. sinuata_),[3] flying indolently
from gallery to gallery, doubtless with the object of laying their
eggs there; and here are others, more numerous, whose mission is
fulfilled and who, having died in harness, are hanging dry and
shrivelled in the Spiders' webs. Elsewhere the entire surface of a
perpendicular bank is hung with the dried corpses of a Beetle
(_Sitaris humeralis_), slung, like the Flies, in the silken meshes of
the Spiders. Among these corpses some male Sitares circle, busy,
amorous, heedless of death, mating with the first female that passes
within reach, while the fertilized females thrust their bulky abdomens
into the opening of a gallery and disappear into it backwards. It is
impossible to mistake the situation: some grave interest attracts to
this spot these two insects, which, within a few days, make their
appearance, mate, lay their eggs and die at the very doors of the
Anthophora's dwellings.

[Footnote 3: Cf. _The Life of the Fly_, by J. Henri Fabre, translated
by Alexander Teixeira de Mattos: chaps. ii. and iv.--_Translator's
Note_.]

Let us now give a few blows of the pick to the surface beneath which
the singular incidents already in our mind must be occurring, beneath
which similar things occurred last year; perhaps we shall find some
evidence of the parasitism which we suspected. If we search the
dwellings of the Anthophorae during the early days of August, this is
what we see: the cells forming the superficial layer are not like
those situated at a greater depth. This difference arises from the
fact that the same establishment is exploited simultaneously by the
Anthophora and by an Osmia (_O. tricornis_)[4] as is proved by an
observation made at the working-period, in May. The Anthoph