e the
order of her laying and to start with a more or less long series of
males before producing any females. In the first case, the first female
appears as number 7; in the third, as number 17. There is something
better still; and this is the proposition which I was particularly
anxious to prove: the female sex can be permuted with the male sex and
can be permuted to the point of disappearing altogether. We see this
especially in the third case, where the presence of a solitary female
in a family of twenty-six is due to the somewhat larger diameter of the
corresponding Snail-shell and also, no doubt, to some mistake on the
mother's part, for the female cocoon, in a series of two, occupies the
upper storey, the one next to the orifice, an arrangement which the
Osmia appears to me to dislike.

This result throws so much light on one of the darkest corners of
biology that I must attempt to corroborate it by means of even more
conclusive experiments. I propose next year to give the Osmiae nothing
but Snail-shells for a lodging, picked out one by one, and rigorously
to deprive the swarm of any other retreat in which the laying could be
effected. Under these conditions, I ought to obtain nothing but males,
or nearly, for the whole swarm.

There would still remain the inverse permutation: to obtain only females
and no males, or very few. The first permutation makes the second seem
very probable, although I cannot as yet conceive a means of realizing
it. The only condition which I can regulate is the dimensions of the
home. When the rooms are small, the males abound and the females tend to
disappear. With generous quarters, the converse would not take place. I
should obtain females and afterwards an equal number of males, confined
in small cells which, in case of need, would be bounded by numerous
partitions. The factor of space does not enter into the question here.
What artifice can we then employ to provoke this second permutation? So
far, I can think of nothing that is worth attempting.

It is time to conclude. Leading a retired life, in the solitude of
a village, having quite enough to do with patiently and obscurely
ploughing my humble furrow, I know little about modern scientific views.
In my young days I had a passionate longing for books and found it
difficult to procure them; to-day, when I could almost have them if I
wanted, I am ceasing to wish for them. It is what usually happens as
life goes on. I do not there