al frontage of the theatre whither all the
intellectual world once flocked to hear Sophocles' "Oedipus Tyrannus,"
derive most of their material from these quarries. Other evidence
confirms what the similarity of the hewn stone tells us. Among the
rubbish that fills up the spaces between the tiers of seats, they
occasionally discover the Marseilles obol, a bit of silver stamped
with the four-spoked wheel, or a few bronze coins bearing the effigy of
Augustus or Tiberius. Scattered also here and there among the monuments
of antiquity are heaps of refuse, accumulations of broken stones
in which various Hymenoptera, including the Three-horned Osmia in
particular, take possession of the dead Snail-shell.

The quarries form part of an extensive plateau which is so arid as to be
nearly deserted. In these conditions, the Osmia, at all times faithful
to her birth-place, has little or no need to emigrate from her heap of
stones and leave the shell for another dwelling which she would have
to go and seek at a distance. Since there are heaps of stone there, she
probably has no other dwelling than the Snail-shell. Nothing tells us
that the present-day generations are not descended in the direct line
from the generations contemporary with the quarryman who lost his as or
his obol at this spot. All the circumstances seem to point to it: the
Osmia of the quarries is an inveterate user of Snail-shells; so far as
heredity is concerned, she knows nothing whatever of reeds. Well, we
must place her in the presence of these new lodgings.

I collect during the winter about two dozen well-stocked Snail-shells
and instal them in a quiet corner of my study, as I did at the time of
my enquiries into the distribution of the sexes. The little hive with
its front pierced with forty holes has bits of reed fitted to it. At the
foot of the five rows of cylinders I place the inhabited shells and
with these I mix a few small stones, the better to imitate the natural
conditions. I add an assortment of empty Snail-shells, after carefully
cleaning the interior so as to make the Osmia's stay more pleasant. When
the time comes for nest-building, the stay-at-home insect will have,
close beside the house of its birth, a choice of two habitations: the
cylinder, a novelty unknown to its race; and the spiral staircase, the
ancient ancestral home.

The nests were finished at the end of May and the Osmiae began to answer
my list of questions. Some, the great majori