time has come to set up the Frog's gibbet made famous by
Gleditsch. The batrachian is not indispensable; a Mole will serve as
well or even better. With a ligament of raffia I fix him, by his
hind-legs, to a twig which I plant vertically in the ground, inserting
it to no great depth. The creature hangs plumb against the gibbet, its
head and shoulders making ample contact with the soil.

The grave-diggers set to work beneath the part which lies along the
ground, at the very foot of the stake; they dig a funnel into which
the Mole's muzzle, head and neck sink little by little. The gibbet
becomes uprooted as they descend and ends by falling, dragged over by
the weight of its heavy burden. I am assisting at the spectacle of the
overturned stake, one of the most astonishing feats of reason with
which the insect has ever been credited.

This, for one who is considering the problem of instinct, is an
exciting moment. But let us beware of forming conclusions just yet; we
might be in too great a hurry. Let us first ask ourselves whether the
fall of the stake was intentional or accidental. Did the Necrophori
lay it bare with the express purpose of making it fall? Or did they,
on the contrary, dig at its base solely in order to bury that part of
the Mole which lay on the ground? That is the question, which, for the
rest, is very easy to answer.

The experiment is repeated; but this time the gibbet is slanting and
the Mole, hanging in a vertical position, touches the ground at a
couple of inches from the base of the apparatus. Under these
conditions, absolutely no attempt is made to overthrow it. Not the
least scrape of a claw is delivered at the foot of the gibbet. The
entire work of excavation is performed at a distance, under the body,
whose shoulders are lying on the ground. Here and here only a hole is
dug to receive the front of the body, the part accessible to the
sextons.

A difference of an inch in the position of the suspended animal
destroys the famous legend. Even so, many a time, the most elementary
sieve, handled with a little logic, is enough to winnow a confused
mass of statements and to release the good grain of truth.

Yet another shake of this sieve. The gibbet is slanting or
perpendicular, no matter which; but the Mole, fixed by his hind-legs
to the top of the twig, does not touch the soil; he hangs a few
fingers'-breadths from the ground, out of the sextons' reach.

What will they do now? Will they scrap