ded by day,
renewed at night and in the morning hours, until completely finished.

The passages of the Cylindrical Halictus descend to a depth of some
eight inches and branch into secondary corridors, each giving access
to a set of cells. These number six or eight to each set and are ranged
side by side, parallel with their main axis, which is almost horizontal.
They are oval at the base and contracted at the neck. Their length is
nearly twenty millimetres (.78 inch.--Translator's Note.) and their
greatest width eight. (.312 inch.--Translator's Note.) They do not
consist simply of a cavity in the ground; on the contrary, they have
their own walls, so that the group can be taken out in one piece, with
a little precaution, and removed neatly from the earth in which it is
contained.

The walls are formed of fairly delicate materials, which must have
been chosen in the coarse surrounding mass and kneaded with saliva.
The inside is carefully polished and upholstered with a thin waterproof
film. We will cut short these details concerning the cells, which the
Zebra Halictus has already shown us in greater perfection, leave the
home to itself and come to the most striking feature in the life-history
of the Halicti.

The Cylindrical Halictus is at work in the first days of May. It is
a rule among the Hymenoptera for the males never to take part in
the fatiguing work of nest-building. To construct cells and to amass
victuals are occupations entirely foreign to their nature. This rule
seems to have no exceptions; and the Halicti conform to it like the
rest. It is therefore only to be expected that we should see no males
shooting the underground rubbish outside the galleries. That is not
their business.

But what does astonish us, when our attention is directed to it, is the
total absence of any males in the vicinity of the burrows. Although it
is the rule that the males should be idle, it is also the rule for these
idlers to keep near the galleries in course of construction, coming and
going from door to door and hovering above the work-yards to seize the
moment at which the unfecundated females will at last yield to their
importunities.

Now here, despite the enormous population, despite my careful and
incessant watch, it is impossible for me to distinguish a single male.
And yet the distinction between the sexes is of the simplest. It is
not necessary to take hold of the male. He can be recognized even at a
distance by hi