teresting to the bees,
whereas, during the period of swarming, it is necessary to preserve a
succession of queens, for conducting the different colonies; and to
ensure the safety of the queens, it is necessary to avert the
consequences of the mutual horror by which they are animated against
each other. Behold the evident cause of all the precautions that bees,
instructed by nature, take during the period of swarming; behold an
explanation of the captivity of females; and that the duration of their
captivity might be ascertained by the age of the young queens, it was
requisite for them to have some method of communicating to the workers
when they should be liberated. This method consists in the sound
emitted, and the variation they are able to give it.

In spite of all my researches, I have never been able to discover the
situation of the organ which produces the sound. But I have instituted a
new course of experiments on the subject, which are still unfinished.

Another problem still remains for solution. Why are the queens reared,
according to M. Schirach's method, mute, whilst those bred in the time
of swarming have the faculty of emitting a certain sound? What is the
physical cause of this difference? At first I thought it might be
ascribed to the period of life, when the worms that are to become queens
receive the royal food. While hives swarm, the royal worms receive the
food adapted for queens, from the moment of leaving the egg; those on
the contrary, destined for queens, according to M. Schirach's method,
receive it only the second or third day of their existence. It appears
to me that this circumstance may have an influence on the different
parts of organisation, and particularly on the organ of voice.
Experiment has not confirmed this conjecture. I constructed glass cells
in perfect imitation of royal cells, that the metamorphosis of the worms
into nymphs, and of the nymphs to queens, might be visible. These
experiments are related in a preceding letter. Into one of these
artificial cells we introduced the nymph of a worm, reared according to
M. Schirach's method, twenty-four hours before it could naturally
undergo its last metamorphosis; and we replaced the glass cell in the
hive, that the nymph might have the necessary degree of heat. Next day,
we had the satisfaction of seeing it divest itself of the spoil, and
assume its ultimate figure. This queen was prevented from escaping from
her prison; but we had c