as if the dish were a
Cetonia-larva. The change of diet, complete though it is, has in no way
affected the appetite of the Scolia-grubs. But this prosperous condition
does not last long. About the fourth day, a little sooner in one case,
a little later in another, the three Ephippigers become putrid and the
Scoliae die at the same time.

This result is eloquent. Had I left the egg of the Sphex to hatch, the
larva coming out of it would have fed upon the Ephippiger; and for the
hundredth time I should have witnessed an incomprehensible spectacle,
that of an animal which, devoured piecemeal for nearly a fortnight,
grows thin and empty, shrivels up and yet retains to the very end the
freshness peculiar to living flesh. Substitute for this Sphex-larva a
Scolia-larva of almost the same size; let the dish be the same though
the guest is different; and healthy live flesh is promptly replaced
by pestilent rotten flesh. That which under the mandibles of the Sphex
would for a long while have remained wholesome food promptly becomes a
poisonous liquescence under the mandibles of the Scolia.

It is impossible to explain the preservation of the victuals until
finally consumed by supposing that the venom injected by the Wasp when
she delivers her paralysing stings possesses antiseptic properties.
The three Ephippigers were operated on by the Sphex. Able to keep fresh
under the mandibles of the Sphex-larvae, why did they promptly go bad
under the mandibles of the Scolia-larvae? Any idea of an antiseptic must
needs be rejected: a liquid preservative which would act in the first
case could not fail to act in the second, as its virtues would not
depend on the teeth of the consumer.

Those of you who are versed in the knowledge attaching to this problem,
investigate, I beg you, search, sift, see if you can discover the reason
why the victuals keep fresh when consumed by a Sphex, whereas they
promptly become putrid when consumed by a Scolia. For me, I see only one
reason; and I very much doubt whether any one can suggest another.

Both larvae practise a special art of eating, which is determined by the
nature of the game. The Sphex, when sitting down to an Ephippiger, the
food that has fallen to its lot, knows thoroughly how to consume it and
how to preserve, to the very end, the glimmer of life which keeps it
fresh; but, if it has to browse upon a Cetonia-grub, whose different
structure would confuse its talents as a dissector, it woul