ff 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.

In the following year, 1881, I began experimenting again, but in a
different way. Hitherto, I had worked on the level. To return to the
nest, my lost Bees had only to cross slight obstacles, the hedges
and spinneys of the tilled fields. To-day, I propose to add to
the difficulties of distance those of the ground to be traversed.
Discontinuing all my backing- and whirling-tactics, things which I
recognize as useless, I think of releasing my Chalicodomae in the thick
of the Serignan Woods. How will they escape from that labyrinth, where,
in the early days, I needed a compass to find my way? Moreover, I
shall have an assistant with me, a pair of eyes younger than mine and
better-fitted to follow my insects' first flight. That immediate start
in the direction of the nest has already been repeated very often and is
beginning to interest me more than the return itself. A pharmaceutical
student, spending a few days with my parents, shall be my eyewitness.
With him, I shall feel at ease; science and he are no stranger