rking-places, to examine them under the lens. The
first has Sitaris-larvae on her thorax; so has the second; the third
and fourth likewise; and so on, as far as I care to pursue the
examination. I change galleries ten times, twenty times; the result is
invariable. Then, for me, occurred one of the moments which come to
those who, after considering and reconsidering an idea for years and
years from every point of view, are at last able to cry: "Eureka!"

On the days that followed, a serene and balmy sky enabled the
Anthophorae to leave their retreats and scatter over the countryside
and despoil the flowers. I renewed my examination on those Anthophorae
flying incessantly from one flower to another, whether in the
neighbourhood of the places where they were born or at great distances
from these places. Some were without Sitaris-larvae; others, more
numerous, had two, three, four, five or more among the hairs of their
thorax. At Avignon, where I have not yet seen _Sitaris humeralis_, the
same species of Anthophora, observed at almost the same season, while
pillaging the lilac-blossom, was always free of young Sitaris-grubs;
at Carpentras, on the contrary, where there is not a single
Anthophora-colony without Sitares, nearly three-quarters of the
specimens which I examined carried a few of these larvae in their
fleece.

But, on the other hand, if we look for these larvae in the
entrance-lobbies where we found them, a few days ago, piled up in
heaps, we no longer see them. Consequently, when the Anthophorae,
having opened their cells, enter the galleries to reach the exit and
fly away, or else when the bad weather and the darkness bring them
back there for a time, the young Sitaris-larvae, kept on the alert in
these same galleries by the stimulus of instinct, attach themselves to
the Bees, wriggling into their fur and clutching it so firmly that
they need not fear a fall during the long journeys of the insect which
carries them. By thus attaching themselves to the Anthophorae the
young Sitares evidently intend to get themselves carried, at the
opportune moment, into the victualled cells.

One might even at first sight believe that they live for some time on
the Anthophora's body, just as the ordinary parasites, the various
species of Lice, live on the body of the animal that feeds them. But
not at all. The young Sitares, embedded in the fleece, at right angles
to the Anthophora's body, head inwards, rump outwards, do not