e mistake was
soon exposed. I plucked an acorn just as the mother withdrew, after
having for a moment applied the tip of the abdomen to the orifice of the
passage just opened by her rostrum. The egg, so it seemed, must be
there, at the entrance of the passage.... But no, it was not! It was at
the other extremity of the passage! If I dared, I would say it had
dropped like a stone into a well.

That idea we must abandon at once; the passage is extremely narrow and
encumbered with shavings, so that such a thing would be impossible.
Moreover, according to the direction of the stem, accordingly as it
pointed upwards or downwards, the egg would have to fall downwards in
one acorn and upwards in another.

A second explanation suggests itself, not less perilous. It might be
said: "The cuckoo lays her egg on the grass, no matter where; she lifts
it in her beak and places it in the nearest appropriate nest." Might not
the Balaninus follow an analogous method? Does she employ the rostrum to
place the egg in its position at the base of the acorn? I cannot see
that the insect has any other implement capable of reaching this remote
hiding-place.

Nevertheless, we must hastily reject such an absurd explanation as a
last, desperate resort. The elephant-beetle certainly does not lay its
egg in the open and seize it in its beak. If it did so the delicate ovum
would certainly be destroyed, crushed in the attempt to thrust it down a
narrow passage half choked with debris.

This is very perplexing. My embarrassment will be shared by all readers
who are acquainted with the structure of the elephant-beetle. The
grasshopper has a sabre, an oviscapt which plunges into the earth and
sows the eggs at the desired depth; the Leuscopis has a probe which
finds its way through the masonry of the mason-bee and lays the egg in
the cocoon of the great somnolent larva; but the Balaninus has none of
these swords, daggers, or pikes; she has nothing but the tip of her
abdomen. Yet she has only to apply that abdominal extremity to the
opening of the passage, and the egg is immediately lodged at the very
bottom.

Anatomy will give us the answer to the riddle, which is otherwise
indecipherable. I open the body of a gravid female. There, before my
eyes, is something that takes my breath away. There, occupying the whole
length of the body, is an extraordinary device; a red, horny, rigid rod;
I had almost said a rostrum, so greatly does it resemble the imple