ting about, sounding the depths. The
endeavour is frequently repeated, while the whole troop stops. The
caterpillars' heads give sudden jerks, their bodies wriggle.

One of the pioneers decides to take the plunge. He slips under the
ledge. Four follow him. The others, still confiding in the perfidious
silken path, dare not copy him and continue to go along the old road.

The short string detached from the general chain gropes about a great
deal, hesitates long on the side of the vase; it goes half-way down,
then climbs up again slantwise, rejoins and takes its place in the
procession. This time the attempt has failed, though at the foot of the
vase, not nine inches away, there lay a bunch of pine-needles which I
had placed there with the object of enticing the hungry ones. Smell and
sight told them nothing. Near as they were to the goal, they went up
again.

No matter, the endeavour has its uses. Threads were laid on the way and
will serve as a lure to further enterprise. The road of deliverance has
its first landmarks. And, two days later, on the eighth day of the
experiment, the caterpillars--now singly, anon in small groups, then
again in strings of some length--come down from the ledge by following
the staked-out path. At sunset the last of the laggards is back in the
nest.

Now for a little arithmetic. For seven times twenty-four hours the
caterpillars have remained on the ledge of the vase. To make an ample
allowance for stops due to the weariness of this one or that and above
all for the rest taken during the colder hours of the night, we will
deduct one-half of the time. This leaves eighty-four hours' walking.
The average pace is nine centimetres a minute. (3 1/2
inches.--Translator's Note.) The aggregate distance covered, therefore,
is 453 metres, a good deal more than a quarter of a mile, which is a
great walk for these little crawlers. The circumference of the vase,
the perimeter of the track, is exactly 1 metre 35. (4 feet 5
inches.--Translator's Note.) Therefore the circle covered, always in
the same direction and always without result, was described three
hundred and thirty-five times.

These figures surprise me, though I am already familiar with the
abysmal stupidity of insects as a class whenever the least accident
occurs. I feel inclined to ask myself whether the Processionaries were
not kept up there so long by the difficulties and dangers of the
descent rather than by the lack of any gleam of in