interesting experiments as to the effects of perfume on dogs;
civet and castoreum were found to have the most powerfully
exciting effect.

The influences of smell are equally omnipotent in the sexual life
of many insects. Thus, Féré has found that in cockchafers sexual
coupling failed to take place when the antennæ, which are the
organs of smell, were removed; he also found that males, after
they had coupled with females, proved sexually attractive to
other males (_Comptes Rendus de la Société de Biologie_, May 21,
1898). Féré similarly found that, in a species of _Bombyx_, males
after contact with females sometimes proved attractive to other
males, although no abnormal relationships followed. (_Soc. de
Biol_, July 30, 1898.)

With the advent of the higher apes, and especially of man, all this has
been changed. The sense of smell, indeed, still persists universally and
it is still also exceedingly delicate, though often neglected.[25] It is,
moreover, a useful auxiliary in the exploration of the external world,
for, in contrast to the very few sensations furnished to us by touch and
by taste, we are acquainted with a vast number of smells, though the
information they give us is frequently vague. An experienced perfumer,
says Piesse, will have two hundred odors in his laboratory and can
distinguish them all. To a sensitive nose nearly everything smells. Passy
goes so far as to state that he has "never met with any object that is
really inodorous when one pays attention to it, not even excepting glass,"
and, though we can scarcely accept this statement absolutely,--especially
in view of the careful experiments of Ayrton, which show that, contrary
to a common belief, metals when perfectly clean and free from traces of
contact with the skin or with salt solutions have no smell,--odor is still