For the first time, both sexes are present.
Males, so easily recognized by their black livery and their slim abdomen
adorned with a red ring, hover backwards and forwards, almost level with
the ground. They fuss about from burrow to burrow. A few rare females
come out for a moment and then go in again.

I proceed to make an excavation with my spade; I gather indiscriminately
whatever I come across. Larvae are very scarce; pupae abound, as do
perfect insects. The list of my captures amounts to eighty males and
fifty-eight females. The males, therefore, hitherto impossible to
discover, either on the flowers around or in the neighbourhood of the
burrows, could be picked up to-day by the hundred, if I wished. They
outnumber the females by about four to three; they are also further
developed, in accordance with the general rule, for most of the backward
pupae give me only females.

Once the two sexes had appeared, I expected a third generation that
would spend the winter in the larval state and recommence in May the
annual cycle which I have just described. My anticipation proved to be
at fault. Throughout September, when the sun beats upon the burrows,
I see the males flitting in great numbers from one shaft to the other.
Sometimes a female appears, returning from the fields, but with no
pollen on her legs. She seeks her gallery, finds it, dives down and
disappears.

The males, as though indifferent to her arrival, offer her no welcome,
do not harass her with their amorous pursuits; they continue to visit
the doors of the burrows with a winding and oscillating flight. For two
months, I follow their evolutions. If they set foot on earth, it is to
descend forthwith into some gallery that suits them.

It is not uncommon to see several of them on the threshold of the same
burrow. Then each awaits his turn to enter; they are as peaceable in
their relations as the females who are joint owners of a burrow. At
other times, one wants to go in as a second is coming out. This sudden
encounter produces no strife. The one leaving the hole withdraws a
little to one side to make enough room for two; the other slips past as
best he can. These peaceful meetings are all the more striking when we
consider the usual rivalry between males of the same species.

No rubbish-mound stands at the mouth of the shafts, showing that the
building has not been resumed; at the most, a few crumbs of earth are
heaped outside. And by whom, pray? By the m