om the natural state. I attended to
the experiment fifteen days. Every fine morning, the young captive left
her hive; she traversed her glass prison, and flew much about, and with
great facility. She laid none during this interval, for she had not
united with a male. On the sixteenth day, I set her at liberty: she left
the hive, rose aloft in the air, and soon returned with full evidence of
impregnation. In two days, she laid, first the eggs of workers, and
afterwards as many as the most fertile queens.

It thence followed, 1. That captivity did not alter the organs of
queens. 2. When fecundation took place within the first sixteen days,
she produced both species of eggs.

This was an important experiment. It rendered my labours much more
simple, by clearly pointing out the method to be pursued: it absolutely
precluded the supposed influence of captivity; and left nothing for
investigation but the consequences of retarded fecundation.

With this view, I repeated the experiment; but, instead of giving the
virgin queen liberty on the sixteenth day, I retained her until the
twenty-first. She departed, rose high in the air, was fecundated, and
returned. Thirty-six hours afterwards, she began to lay: but it was the
eggs of males only, and, although very fruitful afterwards, she laid no
other kind.

I occupied myself the remainder of 1787, and the two subsequent years,
with experiments on retarded fecundation, and had constantly the same
results. It is undoubted, therefore, that when the copulation of queens
is retarded beyond the twentieth day, only an imperfect impregnation is
operated: instead of laying the eggs of workers and males equally, they
will lay none but those of males.

I do not aspire to the honour of explaining this singular fact. When the
course of my experiments led me to observe that some queens laid only
the eggs of drones, it was natural to investigate the proximate cause of
such a singularity; and I ascertained that it arose from retarded
fecundation. My evidence is demonstrative, for I can always prevent
queens from laying the eggs of workers, by retarding their fecundation
until the twenty-second or twenty-third day. But, what is the remote
cause of this peculiarity; or, in other words, why does the delay of
impregnation render queens incapable of laying the eggs of workers? This
is a problem on which analogy throws no light: nor in all physiology am
I acquainted with any fact that bears the small