f wood not a twenty-fifth of an inch thick is left
intact at the end of the vestibule. There is no other defensive
precaution; no barricade, no heap of shavings. In order to come out,
the insect has only to pierce an insignificant sheet of wood and then
the bark.

The Nine-spotted Buprestis (_Ptosima novemmaculata_) behaves in the
apricot-tree precisely as the Bronze Buprestis does in the poplar. Its
larva bores the inside of the trunk with very low-ceilinged galleries,
usually parallel with the axis; then, at a distance of an inch and a
quarter or an inch and a half from the surface, it suddenly makes a
sharp turn and proceeds in the direction of the bark. It tunnels
straight ahead, taking the shortest road, instead of advancing by
irregular windings as at first. Moreover, a sensitive intuition of
coming events inspires its chisel to alter the plan of work. The
perfect insect is a cylinder; the grub, wide in the thorax but slender
elsewhere, is a strap, a ribbon. The first, with its unyielding
cuirass, needs a cylindrical passage; the second needs a very low
tunnel, with a roof that will give a purchase to the ambulatory
nipples of the back. The larva therefore changes its manner of boring
utterly: yesterday, the gallery, suited to a wandering life in the
thickness of the wood, was a wide burrow with a very low ceiling,
almost a slot; to-day the passage is cylindrical: a gimlet could not
bore it more accurately. This sudden change in the system of
road-making on behalf of the coming insect once more suggests for our
meditation the eminent degree of foresight possessed by a bit of an
intestine.

The cylindrical exit-way passes through the strata of wood along the
shortest line, almost normally, after a slight bend which connects the
vertical with the horizontal, a curve with a radius large enough to
allow the stiff Buprestis to tack about without difficulty. It ends in
a blind-alley, less than a twelfth of an inch from the surface of the
wood. The eating away of the untouched sheet of wood and of the bark
is all the labour that the grub leaves the insect to perform. Having
made these preparations, the larva withdraws, strengthening the wooden
screen, however, with a layer of fine sawdust; it reaches the end of
the round gallery, which is prolonged by the completely choked flat
gallery; and here, scorning a special chamber or any upholstery, it
goes to sleep for the nymphosis, with its head towards the exit.

I find