ing at the top. The insects, therefore,
are in the exact position which they occupied in the nest. To open a
passage, they must do what they would have done without my interference,
they must break through the wall situated above their heads. I shelter
the whole under a wide bell-glass and wait for the month of May, the
period of the deliverance.

The results far exceed my anticipations. The clay stopper, the work of
my fingers, is perforated with a round hole, differing in no wise from
that which the Mason-bee contrives through her native mortar dome. The
vegetable barrier, new to my prisoners, namely, the sorghum cylinder,
also opens with a neat orifice, which might have been the work of a
punch. Lastly, the brown-paper cover allows the Bee to make her exit
not by bursting through, by making a violent rent, but once more by a
clearly defined round hole. My Bees therefore are capable of a task for
which they were not born; to come out of their reed cells they do what
probably none of their race did before them; they perforate the wall of
sorghum-pith, they make a hole in the paper barrier, just as they would
have pierced their natural clay ceiling. When the moment comes to free
themselves, the nature of the impediment does not stop them, provided
that it be not beyond their strength; and henceforth the argument of
incapacity cannot be raised when a mere paper barrier is in question.

In addition to the cells made out of bits of reed, I put under the
bell-glass, at the same time, two nests which are intact and still
resting on their pebbles. To one of them I have attached a sheet of
brown paper pressed close against the mortar dome. In order to come out,
the insect will have to pierce first the dome and then the paper, which
follows without any intervening space. Over the other, I have placed a
little brown paper cone, gummed to the pebble. There is here, therefore,
as in the first case, a double wall--a clay partition and a paper
partition--with this difference, that the two walls do not come
immediately after each other, but are separated by an empty space of
about a centimetre at the bottom, increasing as the cone rises.

The results of these two experiments are quite different. The Bees
in the nest to which a sheet of paper was tightly stuck come out by
piercing the two enclosures, of which the outer wall, the paper wrapper,
is perforated with a very clean round hole, as we have already seen in
the reed cells clos