me of them were
occupied on the first few days of the laying; and the Osmia who had
started with a home of this sort would pass next to a second
Snail-shell, in the immediate neighbourhood of the first, to a third, a
fourth and others still, always close together, until her ovaries were
emptied. The whole family of one mother would thus be lodged in
Snail-shells which were duly marked with the date of the laying and a
description of the worker. The faithful adherents of the Snail-shell
were in the minority. The greater number left the tubes to come to the
shells and then went back from the shells to the tubes. All, after
filling the spiral staircase with two or three cells, closed the house
with a thick earthen stopper on a level with the opening. It was a long
and troublesome task, in which the Osmia displayed all her patience as
a mother and all her talents as a plasterer.

When the pupae are sufficiently matured, I proceed to examine these
elegant abodes. The contents fill me with joy: they fulfil my
anticipations to the letter. The great, the very great majority of the
cocoons turn out to be males; here and there, in the bigger cells, a
few rare females appear. The smallness of the space has almost done
away with the stronger sex. This result is demonstrated by the
sixty-eight Snail-shells colonized. But, of this total number, I must
use only those series which received an entire laying and were occupied
by the same Osmia from the beginning to the end of the egg-season. Here
are a few examples, taken from among the most conclusive.

From the 6th of May, when she started operations, to the 25th of May,
the date at which her laying ceased, one Osmia occupied seven
Snail-shells in succession. Her family consists of fourteen cocoons, a
number very near the average; and, of these fourteen cocoons, twelve
belong to males and only two to females.

Another, between the 9th and 27th of May, stocked six Snail-shells with
a family of thirteen, including ten males and three females.

A third, between the 2nd and 29th of May colonized eleven Snail-shells,
a prodigious task. This industrious one was also exceedingly prolific.
She supplied me with a family of twenty-six, the largest which I have
ever obtained from one Osmia. Well, this abnormal progeny consisted of
twenty-five males and one female.

There is no need to go on, after this magnificent example, especially
as the other series would all, without exception, give us