er the
twig fell to the ground.

Using one of the most favourable materials--flannel, for example--I
witnessed a curious sight. I placed a morsel of flannel on which the
mother moth had been lying all the morning at the bottom of a long
test-tube or narrow-necked bottle, just permitting of the passage of a
male moth. The visitors entered the vessels, struggled, and did not know
how to extricate themselves. I had devised a trap by means of which I
could exterminate the tribe. Delivering the prisoners, and removing the
flannel, which I placed in a perfectly closed box, I found that they
re-entered the trap; attracted by the effluvia that the flannel had
communicated to the glass.

I was now convinced. To call the moths of the countryside to the
wedding-feast, to warn them at a distance and to guide them the nubile
female emits an odour of extreme subtlety, imperceptible to our own
olfactory sense-organs. Even with their noses touching the moth, none of
my household has been able to perceive the faintest odour; not even the
youngest, whose sensibility is as yet unvitiated.

This scent readily impregnates any object on which the female rests for
any length of time, when this object becomes a centre of attraction as
active as the moth herself until the effluvium is evaporated.

Nothing visible betrays the lure. On a sheet of paper, a recent
resting-place, around which the visitors had crowded, there was no
visible trace, no moisture; the surface was as clean as before the
impregnation.

The product is elaborated slowly, and must accumulate a little before it
reveals its full power. Taken from her couch and placed elsewhere the
female loses her attractiveness for the moment and is an object of
indifference; it is to the resting-place, saturated by long contact,
that the arrivals fly. But the female soon regains her power.

The emission of the warning effluvium is more or less delayed according
to the species. The recently metamorphosed female must mature a little
and her organs must settle to their work. Born in the morning, the
female of the Great Peacock moth sometimes has visitors the night of the
same day; but more often on the second day, after a preparation of forty
hours or so. The Oak Eggar does not publish her banns of marriage before
the third or fourth day.

Let us return for a moment to the problematical function of the antennae.
The male Oak Eggar has a sumptuous pair, as has the Great Peacock or
Emperor