between the two dishes; they thrive equally on the game chosen by me and
that selected by the mother. If the mother sets no value on the
Grasshopper, what then can be the reason of her refusal? I can see only
one: this quarry, which is not hers, perhaps inspires her with fear, as any
unknown thing might do; the ferocious Mantis does not alarm her, but the
peaceable Grasshopper terrifies her. And then, if she were to overcome her
apprehensions, she does not know how to master the Acridian and, above all,
how to operate upon him. To every man his trade, to every Wasp her own way
of wielding her sting. Modify the conditions ever so slightly; and these
skilful paralysers are at an utter loss.

To every insect also its own art of fashioning the cocoon, an art which
varies greatly, an art in which the larva displays all the resources of its
instincts. The Tachytes, the Bembeces, the Stizi, the Palari and other
burrowers build composite cocoons, hard as fruit-stones, formed of an
encrustation of sand in a network of silk. We are already acquainted with
the work of the Bembex. I will recall the fact that their larva first
weaves a conical, horizontal bag of pure white silk, with wide meshes, held
in place by interlaced threads which fix it to the walls of the cell. I
have compared this bag, because of its shape, with a fishtrap. Without
leaving this hammock, stretching its neck through the orifice, the worker
gathers from without a little heap of sand, which it stores inside its
workshop. Then, selecting the grains one by one, it encrusts them all
around itself in the fabric of the bag and cements them with the fluid from
its spinnerets, which hardens at once. When this task is finished, the
house has still to be closed, for it has been wide open all this time to
permit of the renewal of the store of sand as the heap inside becomes
exhausted. For this purpose a cap of silk is woven across the opening and
finally encrusted with the materials which the larva has retained at its
disposal.