not selecting; I am
recording it in the order of my discoveries. The Shagreen Saperda (_S.
carcharias_) lives in the black poplar; the Scalary Saperda (_S.
scalaris_) lives in the cherry-tree. In both we find the same
organization and the same implements, as is fitting in two
closely-related species. The Saperda of the Poplar adopts the method
of the Capricorn of the Oak in its general features. It inhabits the
interior of the trunk. On the approach of the transformation, it makes
an exit-gallery, the door of which is open or else masked by a remnant
of bark. Then, retracing its steps, it blocks the passage with a
barricade of coarse packed shavings; and, at a depth of about eight
inches, not far from the heart of the tree, it hollows out a cavity
for the nymphosis without any particular upholstering. The defensive
system is limited to the long column of shavings. To deliver itself,
the insect will only have to push the heap of woody rubbish back, in
so many lots; the path will open in front of it ready-made. If some
screen of bark hide the gallery from the outside, its mandibles will
easily dispose of that: it is soft and not very thick.

The Scalary Saperda imitates the habits of its messmate, the Capricorn
of the Cherry-tree. Its larva lives between the wood and the bark. To
undergo its transformation, it goes down instead of coming up. In the
sap-wood, parallel with the surface of the trunk, under a layer of
wood barely a twenty-fifth of an inch in thickness, it makes a
cylindrical cell, rounded at the ends and roughly padded with ligneous
fibres. A solid plug of shavings barricades the entrance, which is not
preceded by any vestibule. Here the work of deliverance is the
simplest. The Saperda has only to clear the door of his chamber to
find beneath his mandibles the little bit of bark that remains to be
pierced. As you see, we once more have to do with two specialists,
each working in his own manner with the same tools.

The Buprestes, as zealous as the Longicorns in the destruction of
trees, whether sound or ailing, tell us the same tale as the Cerambyx-
and Saperda-beetles. The Bronze Buprestis (_B. aenea_) is an inmate of
the black poplar. Her larva gnaws the interior of the trunk. For the
nymphosis it installs itself near the surface in a flattened, oval
cell, which is prolonged at the back by the wandering-gallery, firmly
packed with wormed wood, and in front by a short, slightly curved
vestibule. A layer o