Shall we credit it to the Bruchus?
Did the ingenious insect conceive the undertaking?
Did it think out a plan and work out a scheme of its own devising?
This would be no small triumph for the brain of a weevil.

Before coming to a conclusion let us try an experiment.
I deprive certain occupied peas of their skin, and I dry them with abnormal rapidity, placing them in glass test-tubes.

The grubs prosper as well as in the intact peas.

At the proper time the preparations for emergence are made.
If the grub acts on its own inspiration, if it ceases to prolong its boring directly it recognises that the outer coating, auscultated from time to time, is sufficiently thin, what will it do under the conditions of the present test?
Feeling itself at the requisite distance from the surface it will stop boring; it will respect the outer layer of the bare pea, and will thus obtain the indispensable protecting screen.
Nothing of the kind occurs.

In every case the passage is completely excavated; the entrance gapes wide open, as large and as carefully executed as though the skin of the pea were in its place.