leave the choice free between the two opposite directions: in
particular, I had sent away my Dog, who was on my right. To-day, the
Bees do not circle round me: some fly away at once; the others, the
greater number, feeling giddy perhaps after the pitching of the
journey and the rolling of the sling, alight on the ground a few yards
away, seem to wait until they are somewhat recovered and then fly off
to the left. I perceived this to be the general flight, whenever I was
able to observe at all. I was back at a quarter to ten. Two Bees with
pink marks were there before me, of whom one was engaged in building,
with her pellet of mortar in her mandibles. By one o'clock in the
afternoon there were seven arrivals; I saw no more during the rest of
the day. Total: seven out of twenty.

Let us be satisfied with this: the experiment has been repeated often
enough, but it does not conclude as Darwin hoped, as I myself hoped,
especially after what I had been told about the Cat. In vain, adopting
the advice given, do I carry my insects first in the opposite
direction to the place at which I intend to release them; in vain,
when about to retrace my steps, do I twirl my sling with every
complication in the way of whirls and twists that I am able to
imagine; in vain, thinking to increase the difficulties, do I repeat
the rotation as often as five times over: at the start, on the road,
on arriving; it makes no difference: the Mason-bees return; and the
proportion of returns on the same day fluctuates between thirty and
forty per cent. It goes to my heart to abandon an idea suggested by so
famous a man of science and cherished all the more readily inasmuch as
I thought it likely to provide a final solution. The facts are there,
more eloquent than any number of ingenious views; and the problem
remains as mysterious as ever.