t surrounded by the
brown ring which appears in course of time. Let us shell them. Many
contain nothing out of the way; the Balaninus has bored them but has not
laid her eggs in them. They resemble the acorns which for hours and
hours were drilled in my laboratory but not utilised. Many, on the
contrary, contain an egg.

Now however distant the entrance of the bore may be, this egg is always
at the bottom of the acorn, within the cup, at the base of the
cotyledonary matter. The cup furnishes a thin film like swan-skin which
imbibes the sapid exudations from the stem, the source of nourishment. I
have seen a young grub, hatched under my eyes, eat as his first
mouthfuls this tender cottony layer, which is moist and flavoured with
tannin.

Such nutriment, juicy and easy of digestion, like all nascent organic
matter, is only found in this particular spot; and it is only there,
between the cup and the base of the cotyledons, that the elephant-beetle
establishes her egg. The insect knows to a nicety the position of the
portions best adapted to the feeble stomach of the newly hatched larva.

Above this is the tougher nutriment of the cotyledons. Refreshed by its
first meal, the grub proceeds to attack this; not directly, but in the
tunnel bored by the mother, which is littered with tiny crumbs and
half-masticated shavings. With this light mealy diet the strength of the
grub increases, and it then plunges directly into the substance of the
acorn.

These data explain the tactics of the gravid mother. What is her object
when, before proceeding to sink her hole, she inspects her acorn, from
above, below, before and behind, with such meticulous care? She is
making sure that the acorn is not already occupied. The larder is amply
stored, but it does not contain enough for two. Never in fact, have I
found two larvae in the same acorn. One only, always only one, digests
the copious meal and converts it into a greenish dust before leaving it
and descending to the ground. Only an insignificant shell remains
uneaten. The rule is, to each grub one acorn.

Before trusting the egg to the acorn it is therefore essential to
subject it to a thorough examination, to discover whether it already has
an occupant. This possible occupant would be at the base of the acorn,
under the cover of the cup. Nothing could be more secret than this
hiding-place. Not an eye could divine the inhabitant if the surface of
the acorn did not bear the mark of a