ognized that, quite apart from
sense-impressions, the animal, including man, possesses certain
psychological resources, certain inspirations that are innate and not
acquired!

CHAPTER VIII
THE PROBLEM OF THE SIREX

The cherry-tree supports a small jet-black Capricorn, _Cerambyx
cerdo_, whose larval habits it was as well to study in order to learn
whether the instincts are modified when the form and the organization
remain identical. Has this pigmy of the family the same talents as the
giant, the ravager of the oak-tree? Does it work on the same
principles? The resemblance between the two, both in the larval state
and in that of the perfect insect, is complete; the denizen of the
cherry-tree is an exact replica, on a smaller scale, of the denizen of
the oak. If instinct is the inevitable consequence of the organism, we
ought to find in the two insects a strict similarity of habits; if
instinct is, on the other hand, a special aptitude favoured by the
organs, we must expect variations in the industry exercised. For the
second time the alternative is forced upon our attention: do the
implements govern the practice of the craft, or does the craft govern
the employment of the implements? Is instinct derived from the organ,
or is the organ instinct's servant? An old dead cherry-tree will
answer our question.

Beneath its ragged bark, which I lift in wide strips, swarms a
population of larvae all belonging to _Cerambyx cerdo_. There are big
larvae and little larvae; moreover, they are accompanied by nymphs.
These details tell us of three years of larval existence, a duration
of life frequent in the Longicorn series. If we hunt the thick of the
trunk, splitting it again and again, it does not show us a single grub
anywhere; the entire population is encamped between the bark and the
wood. Here we find an inextricable maze of winding galleries, crammed
with packed sawdust, crossing, recrossing, shrinking into little
alleys, expanding into wide spaces and cutting, on the one hand, into
the surface layer of the sap-wood and, on the other, into the thin
sheets of the inner bark. The position speaks for itself: the larva of
the little Capricorn has other tastes than its large kinsman's; for
three years it gnaws the outside of the trunk beneath the thin
covering of the bark, while the other seeks a deeper refuge and gnaws
the inside.

The dissimilarity is yet more marked in the preparations for the
nymphosis. Then the w