amount of free space necessitated
by its movements. Moist, soft, and easily compressible soil is to the
larva of the Cigale what digested wood-pulp is to the others. It is
compressed without difficulty, and so leaves a vacant space.

The difficulty is that sometimes the burrow of exit from the
waiting-place is driven through a very arid soil, which is extremely
refractory to compression so long as it retains its aridity. That the
larva, when commencing the excavation of its burrow, has already thrust
part of the detached material into a previously made gallery, now filled
up and disappeared, is probable enough, although nothing in the actual
condition of things goes to support the theory; but if we consider the
capacity of the shaft and the extreme difficulty of making room for such
a volume of debris, we feel dubious once more; for to hide such a
quantity of earth a considerable empty space would be necessary, which
could only be obtained by the disposal of more debris. Thus we are
caught in a vicious circle. The mere packing of the powdered earth
rejected behind the excavator would not account for so large a void. The
Cigale must have a special method of disposing of the waste earth. Let
us see if we can discover the secret.

Let us examine a larva at the moment of emerging from the soil. It is
almost always more or less smeared with mud, sometimes dried, sometimes
moist. The implements of excavation, the claws of the fore-feet, have
their points covered by little globules of mortar; the others bear
leggings of mud; the back is spotted with clay. One is reminded of a
scavenger who has been scooping up mud all day. This condition is the
more striking in that the insect comes from an absolutely dry soil. We
should expect to see it dusty; we find it muddy.

One more step, and the problem of the well is solved. I exhume a larva
which is working at its gallery of exit. Chance postpones this piece of
luck, which I cannot expect to achieve at once, since nothing on the
surface guides my search. But at last I am rewarded, and the larva is
just beginning its excavation. An inch of tunnel, free of all waste or
rubbish, and at the bottom the chamber, the place of rest; so far has
the work proceeded. And the worker--in what condition is it? Let us see.

The larva is much paler in colour than those which I have caught as they
emerged. The large eyes in particular are whitish, cloudy, blurred, and
apparently blind. What would b