skin of the bean contains any edible
matter, so long do new consumers establish themselves within it, so that
the haricot finally becomes a mere shell stuffed with excreta. The skin,
despised by the grubs, is a mere sac, pierced with holes as many as the
inhabitants that have deserted it; the ruin is complete.

The _Bruchus pisi_, a solitary hermit, consumes only so much of the pea
as will leave a cell for the nymph; the rest remains intact, so that the
pea may be sown, or it will even serve as food, if we can overcome our
repugnance. The American insect knows nothing of these limitations; it
empties the haricot completely and leaves a skinful of filth that I have
seen the pigs refuse. America is anything but considerate when she sends
us her entomological pests. We owe the Phylloxera to America; the
Phylloxera, that calamitous insect against which our vine-growers wage
incessant war: and to-day she is sending us the haricot-weevil, which
threatens to be a plague of the future. A few experiments gave me some
idea of the peril of such an invasion.

For nearly three years there have stood, on my laboratory table, some
dozens of jars and bottles covered with pieces of gauze which prevent
escape while permitting of a constant ventilation. These are the cages
of my menagerie. In them I rear the haricot-weevil, varying the system
of education at will. Amongst other things I have learned that this
insect, far from being exclusive in its choice, will accommodate itself
to most of our leguminous foods.

All the haricots suit it, black and white, red and variegated, large and
small; those of the latest crop and those which have been many years in
stock and are almost completely refractory to boiling water. The loose
beans are attacked by preference, as being easier to invade, but when
the loose beans are not available those in the natural shelter of their
pods are attacked with equal zest. However dry and parchment-like the
pods, the grubs have no difficulty in attaining the seeds. When attacked
in the field or garden, the bean is attacked in this way through the
pod. The bean known in Provence as the blind haricot--_lou faiou
borgne_--a bean with a long pod, which is marked with a black spot at
the navel, which has the look of a closed and blackened eye, is also
greatly appreciated; indeed, I fancy my little guests show an obvious
preference for this particular bean.

So far, nothing abnormal; the Bruchus does not wander bey