, I was right: if the thing were feasible, it would be an advantage
for the chemists to collect their digestive drug from the stomach of the
maggot. The worm, in this case, beats the pig and the sheep.

The same method is followed for the remaining experiments. I put the
bluebottle's eggs to hatch on a piece of meat and leave the worms to do
their work as they please. The lean tissues, whether of mutton, beef
or pork, no matter which, are not turned into liquid; they become a pea
soup of a clarety brown. The liver, the lung, the spleen are attacked
to better purpose, without, however, getting beyond the state of a
semi-fluid jam, which easily mixes with water and even appears to
dissolve in it. The brains do not liquefy either: they simply melt into
a thin gruel.

On the other hand, fatty substances, such as beef suet, lard and butter,
do not undergo any appreciable change. Moreover, the worms soon dwindle
away, incapable of growing. This sort of food does not suit them. Why?
Apparently because it cannot be liquefied by the reagent disgorged
by the worms. In the same way, ordinary pepsin does not attack fatty
substances; it takes pancreatin to reduce them to an emulsion. This
curious analogy of properties, positive for albuminous, negative for
fatty matter, proclaims the similarity and perhaps the identity of the
dissolvent discharged by the grubs and the pepsin of the higher animals.

Here is another proof: the usual pepsin does not dissolve the epidermis,
which is a material of a horny nature. That of the maggots does not
dissolve it either. I can easily rear bluebottle grubs on dead crickets
whose bellies I have first opened; but I do not succeed if the morsel
be left intact: the worms are unable to perforate the succulent paunch;
they are stopped by the cuticle, on which their reagent refuses to act.
Or else I give them frogs' hind legs, stripped of their skin. The flesh
turns to broth and disappears to the bone. If I do not peel the legs,
they remain intact in the midst of the vermin. Their thin skin is
sufficient to protect them.

This failure to act upon the epidermis explains why the bluebottle at
work on the animal declines to lay her eggs on the first part that comes
handy. She needs the delicate membrane of the nostrils, eyes or throat,
or else some wound in which the flesh is laid bare. No other place suits
her, however excellent for flavor and darkness. At most, finding nothing
better when my stratagems