l an excess of monotonous
repetition. The general law stands out very clearly from these few
data: the wood-eating grubs of the Longicorns and Buprestes prepare
the path of deliverance for the perfect insect, which will have merely
in one case to pass a barricade of shavings or wormed wood, or in
another to pierce a slight thickness of wood or bark. Thanks to a
curious reversal of its usual attributes, youth is here the season of
energy, of strong tools, of stubborn work; adult age is the season of
leisure, of industrial ignorance, of idle diversions, without trade or
profession. The infant has its paradise in the arms of its mother, its
providence; here the infant, the grub, is the providence of the
mother. With its patient tooth, which neither the perils of the
outside world nor the difficult task of boring through hard wood are
able to deter, it clears a way for her to the supreme delights of the
sun. The youngster prepares an easy life for the adult.

Can these armour-wearers, so sturdy in appearance, be weaklings? I
place nymphs of all the species that come to hand in glass tubes of
the same diameter as the natal cell, lined with coarse paper, which
will provide a good purchase for the boring. The obstacle to be
pierced varies: a cork a centimetre thick;[3] a plug of poplar, very
much softened by decay; a circular disk of sound wood. Most of my
captives easily pierce the cork and the soft wood; these represent to
them the barricade to be overthrown, the bark curtain to be
perforated. A few, however, succumb before the front to be attacked;
and all perish, after fruitless attempts, before the disk of hard
wood. Thus perished the strongest of them all, the Great Capricorn, in
my artificial oak-wood cells and even in my reed-stumps closed with
their natural partitions.

[Footnote 3: .39 inch.--_Translator's Note_.]

They have not the strength, or rather the patient art; and the larva,
more highly gifted, works for them. It gnaws with indomitable
perseverance, an essential to success even for the strong; it digs
with amazing foresight. It knows the future shape of the adult,
whether round or oval, and bores the exit-passage accordingly, making
it cylindrical in one case and elliptical in the other. It knows that
the adult is very impatient to reach the light; and it leads her
thither by the shortest way. In its wandering life in the heart of the
tree, it loves low-roofed, winding tunnels, just big enough to pass
th