ge has no longer been repeated.

To return to the Fly. A piece of meat is hidden in a jar under a layer
of fine, dry sand, a finger's-breadth thick. The jar has a wide mouth
and is left quite open. Let whoso come that will, attracted by the
smell. The Bluebottles are not long in inspecting what I have prepared
for them: they enter the jar, go out and come back again, inquiring
into the invisible thing revealed by its fragrance. A diligent watch
enables me to see them fussing about, exploring the sandy expanse,
tapping it with their feet, sounding it with their proboscis. I leave
the visitors undisturbed for a fortnight or three weeks. None of them
lays any eggs.

This is a repetition of what the paper bag, with its dead bird, showed
me. The Flies refuse to lay on the sand, apparently for the same
reasons. The paper was considered an obstacle which the frail vermin
would not be able to overcome. With sand, the case is worse. Its
grittiness would hurt the new-born weaklings, its dryness would absorb
the moisture indispensable to their movements. Later, when preparing
for the metamorphosis, when their strength has come to them, the grubs
will dig the earth quite well and be able to descend: but, at the
start, that would be very dangerous for them. Knowing these
difficulties, the mothers, however greatly tempted by the smell,
abstain from breeding. As a matter of fact, after long waiting, fearing
lest some packets of eggs may have escaped my attention, I inspect the
contents of the jar from top to bottom. Meat and sand contain neither
larvae nor pupae: the whole is absolutely deserted.

The layer of sand being only a finger's-breadth thick, this experiment
requires certain precautions. The meat may expand a little, in going
bad, and protrude in one or two places. However small the fleshy eyots
that show above the surface, the Flies come to them and breed.
Sometimes also the juices oozing from the putrid meat soak a small
extent of the sandy floor. That is enough for the maggot's first
establishment. These causes of failure are avoided with a layer of sand
about an inch thick. Then the Bluebottle, the Flesh-fly, and other
Flies whose grubs batten on dead bodies are kept at a proper distance.

In the hope of awakening us to a proper sense of our insignificance,
pulpit orators sometimes make an unfair use of the grave and its worms.
Let us put no faith in their doleful rhetoric. The chemistry of man's
final dissolution is