resource; I must attempt the nearly impossible and watch the
Anthrax from the egg onwards.

Although Anthrax flies are fairly common, in the sense of there
being several different species, they are not plentiful when it is
a case of wanting a colony populous enough to admit of continuous
observation. I see them, now here, now there, in the fiercely sun-
scorched places, flitting hither and thither on the old walls, the
slopes and the sand, sometimes in small platoons, most often
singly. I can expect nothing of those vagabonds, who are here
today and gone tomorrow, for I know nothing of their settlements.
To keep a watch on them, one by one, in the blazing heat, is very
painful and very unfruitful, as the swift-winged insect has a habit
of disappearing one knows not whither just when a prospect of
capturing its secret begins to offer. I have wasted many a patient
hour at this pursuit, without the least result.

There might be some chance of success with Anthrax flies whose home
was known to us beforehand, especially if insects of the same
species formed a pretty numerous colony. The inquiries begun with
one would be continued with a second and with more, until a
complete verdict was forthcoming. Now, in the course of my long
entomological career, I have met with but two species of Anthrax
that fulfilled this condition and were to be found regularly: one
at Carpentras; the other at Serignan. The first, Anthrax sinuata,
FALLEN, lives in the cocoons of Osmia tricornis, who herself builds
her nest in the old galleries of the hairy-footed Anthophora; the
second, Anthrax trifasciata, MEIGEN, exploits the Chalicodoma of
the Sheds. I will consult both.