centimeters, I
obtained the liberation of only a single fly. The plucky creature must
have had a hard struggle to mount from so great a depth, for the other
fourteen did not even manage to burst the lid of their caskets.

I presume that the looseness of the sand and the consequent pressure
in every direction, similar to that exercised by fluids, have a certain
bearing on the difficulties of the exhumation. Two more tubes are
prepared, but this time supplied with fresh mould, lightly heaped up,
which has not the incoherence of sand, with the attendant drawback of
pressure. Six centimeters of mould give me eight flies for fifteen pupae
buried; twenty centimeters give me only one. There is less success than
with the sandy column. My device has diminished the pressure, but,
at the same time, increased the passive resistance. The sand falls of
itself under the impact of the frontal rammer; the unyielding mould
demands the cutting of a gallery. In fact, I perceive, on the road
followed, a shaft which continues indefinitely such as it is. The fly
has bored it with the temporary blister that throbs between her eyes.

In every medium, therefore, whether sand, mould or any earthy
combination, great are the sufferings that attend the exhumation of the
fly. And so the maggot shuns the depths which a desire for additional
security might seem to recommend. The worm has its own prudence:
foreseeing the dangers ahead, it refrains from making great descents
that might promote the welfare of the moment. It neglects the present
for the sake of the future.

CHAPTER XVI. A PARASITE OF THE MAGGOT

The dangers of the exhumation are not the only ones; the Bluebottle must
be acquainted with others. Life, when all is said, is a knacker's yard
wherein the devourer of today becomes the devoured of tomorrow; and the
robber of the dead cannot fail to be robbed of her own life when the
time comes. I know that she has one exterminator in the person of the
tiny Saprinus beetle, a fisher of fat sausages on the edge of the pools
formed by liquescent corpses. Here swarm in common the grubs of the
greenbottle, the flesh fly and the bluebottle. The Saprinus draws them
to him from the bank and gobbles them indiscriminately. They represent
to him morsels of equal value.

This banquet can be observed only in the open country, under the rays
of a hot sun. Saprini and greenbottles never enter our houses; the flesh
fly visits us but discreetly, does no