their refectory. As they release
themselves from the egg, without hesitation, so accurate is their scent,
they slip beneath the edge of the ill-joined lid, or through the passage
cut by the knife. Behold them entering upon their promised land, their
reeking paradise.

Eager to arrive, do they drop from the top of the wall? Not they! Slowly
creeping, they make their way down the side of the jar; they use their
fore part, ever in quest of information, as a crutch and grapnel in one.
They reach the meat and at once install themselves upon it.

Let us continue our investigation, varying the conditions. A large
test-tube, measuring nine inches high, is baited at the bottom with a
lump of butcher's meat. It is closed with wire gauze, whose meshes, two
millimeters wide, do not permit of the fly's passage. The bluebottle
comes to my apparatus, guided by scent rather than sight. She hastens to
the test tube whose contents are veiled under an opaque cover with the
same alacrity as to the open tube. The invisible attracts her quite as
much as the visible.

She stays a while on the lattice of the mouth, inspects it attentively;
but, whether because circumstances have failed to serve me, or because
the wire network inspires her with distrust, I never saw her dab her
eggs upon it for certain. As her evidence was doubtful, I had recourse
to the flesh fly (Sarcophaga carnaria).

This fly is less finicky in her preparations, she has more faith in the
strength of her worms, which are born ready-formed and vigorous, and
easily shows me what I wish to see. She explores the trellis-work,
chooses a mesh through which she inserts the tip of her abdomen and,
undisturbed by my presence, emits, one after the other, a certain number
of grubs, about ten or so. True, her visits will be repeated, increasing
the family at a rate of which I am ignorant.

The newborn worms, thanks to a slight viscidity, cling for a moment to
the wire gauze; they swarm, wriggle, release themselves and leap into
the chasm. It is a nine inch drop at least. When this is done, the
mother makes off, knowing for a certainty that her offspring will shift
for themselves. If they fall on the meat, well and good; if they fall
elsewhere, they can reach the morsel by crawling.

This confidence in the unknown factor of the precipice, with no
indication but that of smell, deserves fuller, investigation. From
what height will the flesh fly dare to let her children drop? I top th