they have not had time as yet to grow familiar with it, or
to appreciate its merits; they have prudently abstained from touching
the _ayacot_, whose novelty awoke suspicion. Until our own days the
Mexican bean remained untouched: unlike our other leguminous seeds,
which are all eagerly exploited by the weevil.

This state of affairs could not last. If our own fields do not contain
the insect amateur of the haricot the New World knows it well enough. By
the road of commercial exchange, sooner or later some worm-eaten sack
of haricots must bring it to Europe. The invasion is inevitable.

According to documents now before me, indeed, it has already taken
place. Three or four years ago I received from Maillane, in the
Bouches-du-Rhone, what I sought in vain in my own neighbourhood,
although I questioned many a farmer and housewife, and astonished them
by my questions. No one had ever seen the pest of the haricot; no one
had ever heard of it. Friends who knew of my inquiries sent me from
Maillane, as I have said, information that gave great satisfaction to my
naturalist's curiosity. It was accompanied by a measure of haricots
which were utterly and outrageously spoiled; every bean was riddled with
holes, changed into a kind of sponge. Within them swarmed innumerable
weevils, which recalled, by their diminutive size, the lentil-weevil,
_Bruchus lenti_.

The senders told me of the loss experienced at Maillane. The odious
little creature, they said, had destroyed the greater portion of the
harvest. A veritable plague, such as had never before been known, had
fallen upon the haricots, leaving the housewife barely a handful to put
in the saucepan. Of the habits of the creature and its way of going to
work nothing was known. It was for me to discover them by means of
experiment.

Quick, then, let us experiment! The circumstances favour me. We are in
the middle of June, and in my garden there is a bed of early haricots;
the black Belgian haricots, sown for use in the kitchen. Since I must
sacrifice the toothsome vegetable, let us loose the terrible destroyer
on the mass of verdure. The development of the plant is at the
requisite stage, if I may go by what the _Bruchus pisi_ has already
taught me; the flowers are abundant, and the pods are equally so; still
green, and of all sizes.

I place on a plate two or three handfuls of the infested haricots, and
set the populous heap in the full sunlight by the edge of my bed of
beans.