sense, an undecipherable riddle to ourselves, it knows that the
object of its search lies hidden under this unfamiliar casing.
The sense of smell has already been shown to be out of the
question; that of sight is now eliminated in its turn.

That she should bore through the cocoons of the Stelis, a parasite
of the mason bee, does not surprise me at all: I know how
indifferent my bold visitor is to the nature of the victuals
destined for her family. I have noticed her presence in the homes
of bees differing greatly in size and habits: Anthophorae, Osmiae,
Chalicodomae, Anthidia. The Stelis exploited on my table is one
victim more; and that is all. The interest does not lie there.
The interest lies in the maneuvers of the insect, which I am able
to follow under the most favorable conditions.

Bent sharply at right angles, like a couple of broken matches, the
antennae feel the cocoon with their tips alone. The terminal joint
is the home of this strange sense which discerns from afar what no
eye sees, no scent distinguishes and no ear hears. If the point
explored be found suitable, the insect hoists itself on tiptoe so
as to give full scope to the play of its mechanism; it brings the
tip of the belly a little forward; and the entire ovipositor--
inoculating-needle and scabbard--stands perpendicular to the
cocoon, in the center of the quadrilateral described by the four
hind legs, an eminently favorable position for obtaining the
maximum effect. For some time, the whole of the awl bears on the
cocoon, feeling all round with its point, groping about; then,
suddenly, the boring needle is released from its sheath, which
falls back along the body, while the needle strives to make its
entrance. The operation is a difficult one. I see the insect make