on are identical.

[103] As Moll points out, even the secondary sexual characters have
undergone a somewhat similar change. The beard was once an important
sexual attraction, but men can now afford to dispense with it without fear
of loss in attractiveness. (_Libido Sexualis_, Band I, p. 387.) These
points are discussed at greater length in the fourth volume of these
_Studies_, "Sexual Selection in Man."

[104] It is not absolutely established that in menstruating animals the
period of menstruation is always a period of sexual congress; probably
not, the influence of menstruation being diminished by the more
fundamental influence of breeding seasons, which affect the male also;
monkeys have a breeding season, though they menstruate regularly all the
year round.

[105] See Appendix A.

[106] Bland Sutton, loc. cit., p. 896.

[107] See H. Ellis, _Man and Woman_, Chapter XI.

[108] This is by no means true of European women only. Thus, we read in an
Arabic book, _The Perfumed Garden_, that women have an aversion to coitus
during menstruation. On the other hand, the old Hindoo physician, Susruta,
appears to have stated that a tendency to run after men is one of the
signs of menstruation.

[109] The actual period of the menstrual flow corresponds, in Heape's
terminology, to the congestive stage, or _pro-oestrum_, in female animals;
the _oestrus_, or period of sexual desire, immediately follows the
_pro-oestrum_, and is the direct result of it. See Heape, "The 'Sexual
Season' of Mammals," _Quarterly Journal of Microscopical Science_, 1900,
vol. xliv, Part I.

[110] It may be noted that (as Barnes, Oliver, and others have pointed
out) there is heightened blood-pressure during menstruation. Haig remarks
that he has found a tendency for high pressure to be accompanied by
increased sexual appetite (_Uric Acid_, 6th edition, p. 155).

[111] Sir W.F. Wade, however, remarked, some years ago, in his Ingleby
Lectures (_Lancet_, June 5, 1886): "It is far from exceptional to find
that there is an extreme enhancement of concupiscence in the immediate
precatamenial period," and adds, "I am satisfied that evidence is
obtainable that in some instances, ardor is at its maximum during the
actual period, and suspect that cases occur in which it is almost, if not
entirely, limited to that time." Long ago, however, the genius of Haller
had noted the same fact. More recently, Icard (_La Femme_, Chapter VI and
elsewhere, e.g., p. 125) h