ers in their wire-gauze prisons, no matter in what part of the
house they were placed; they discovered them in the depths of a
wall-cupboard; they divined the secret of all manner of boxes, provided
these were not rigorously air-tight. They came no longer when the box
was hermetically sealed. So far this was only a repetition of the feats
of the Great Peacock.

A box perfectly closed, so that the air contained therein had no
communication with the external atmosphere, left the male in complete
ignorance of the recluse. Not a single one arrived, even when the box
was exposed and plain to see on the window-sill. Thus the idea of
strongly scented effluvia, which are cut off by screens of wood, metal,
card, glass, or what not, returns with double force.

I have shown that the great nocturnal moth was not thrown off the scent
by the powerful odour of naphthaline, which I thought would mask the
extra-subtle emanations of the female, which were imperceptible to human
olfactory organs. I repeated the experiment with the Oak Eggar. This
time I used all the resources of scent and stench that my knowledge of
drugs would permit.

A dozen saucers were arranged, some in the interior of the wire-gauze
cover, the prison of the female, and some around it, in an unbroken
circle. Some contained naphthaline; others the essential oil of
spike-lavender; others petroleum, and others a solution of alkaline
sulphur giving off a stench of rotten eggs. Short of asphyxiating the
prisoner I could do no more. These arrangements were made in the
morning, so that the room should be saturated when the congregation of
lovers should arrive.

In the afternoon the laboratory was filled with the most abominable
stench, in which the penetrating aroma of spike-lavender and the stink
of sulphuretted hydrogen were predominant. I must add that tobacco was
habitually smoked in this room, and in abundance. The concerted odours
of a gas-works, a smoking-room, a perfumery, a petroleum well, and a
chemical factory--would they succeed in confusing the male moths?

By no means. About three o'clock the moths arrived in as great numbers
as usual. They went straight to the cage, which I had covered with a
thick cloth in order to add to their difficulties. Seeing nothing when
once they had entered, and immersed in an extraordinary atmosphere in
which any subtle fragrance should have been annihilated, they
nevertheless made straight for the prisoner, and attempted to r