the arteries. What is food in
one case is poison in the other.

A Liebig's extract of a different kind, the broth in which the liquefier
puddles, is of a virulence equal, if not superior, to that of my
products. All those operated upon, Capricorns, sacred beetles, ground
beetles, die in convulsions. This brings us back, after a long way
round, to our starting point, the maggot of the flesh fly. Can the worm,
constantly floundering in the sanies of a carcass, be itself in danger
of inoculation by that whereon it grows fat? I dare not rely upon
experiments conducted by myself: my clumsy implements and my shaky hand
make me fear that, with subjects so small and delicate, I might inflict
deep wounds which of themselves would bring about death.

Fortunately, I have a collaborator of incomparable skill in the
parasitic Chalcidid. Let us apply to her. To introduce her germs, she
has perforated the maggot's paunch, has even done so several times over.
The holes are extremely small, but the poison all around is excessively
subtle and has thus been able, in certain cases, to penetrate. Now what
has happened? The pupae, all from the same apparatus, are numerous. They
can be divided into three not very unequal classes, according to the
results supplied. Some give me the adult flesh fly, others the parasite.
The rest, nearly a third, give me nothing, neither this year nor next.

In the first two cases, things have taken their normal course: the grub
has developed into a fly, or else the parasite has devoured the grub. In
the third case, an accident has occurred. I open the barren pupae. They
are coated inside with a dark glaze, the remains of the dead maggot
converted into black rottenness. The grub, therefore, has undergone
inoculation by the virus through the fine openings effected by the
Chalcidid. The skin has had time to harden into a shell; but it was too
late, the tissues being already infected.

There you see it: in its broth of putrefaction, the worm is exposed
to grave dangers. Now there is a need for maggots in this world, for
maggots many and voracious, to purge the soil as quickly as possible
of death's impurities. Linnaeus tells us that 'Tres muscae consumunt
cadaver equi aeque cito ac leo.' [Three flies consume the carcass of a
horse as quickly as a lion could do it.] There is no exaggeration about
the statement. Yes, of a certainty, the offspring of the flesh fly and
the bluebottle are expeditious workers. They s