h
it is now unnecessary to discuss in detail, since they have already been
incidentally dealt with in previous volumes of these _Studies_. There is,
for instance, the question of the time of year and the time of the
menstrual cycle which may most properly be selected for procreation.[466]
The best period is probably that when sexual desire is strongest, which is
the period when conception would appear, as a matter of fact, most often
to occur. This would be in spring or early summer,[467] and immediately
after (or shortly before) the menstrual period. The Chinese have observed
that the last day of menstruation and the two following
days--corresponding to the period of oestrus--constitute the most
favorable time for fecundation, and Bossi, of Genoa, has found that the
great majority of successes in both natural and artificial fecundation
occur at this period.[468] Soranus, as well as the Talmud, assigned the
period about menstruation as the best for impregnation, and Susruta, the
Indian physician, said that at this time pregnancy most readily occurs
because then the mouth of the womb is open, like the flower of the
water-lily to the sunshine.

We have now at last reached the point from which we started, the moment of
conception, and the child again lies in its mother's womb. There remains
no more to be said. The divine cycle of life is completed.

FOOTNOTES:

[421] Spencer and Gillen, _Northern Tribes of Central Australia_, p. 330.

[422] Academy of Medicine of Paris, March 31, 1908.

[423] _The Origin and Development of the Moral Ideas_, vol. ii, p. 405.

[424] _Population and Progress_, p. 41.

[425] Cf. Reibmayr, _Entwicklungsgeschichte des Talentes und Genics_, Bd.
II, p. 31.

[426] "The debt that we owe to those who have gone before us," says
Haycraft (_Darwinism and Race Progress_, p. 160), "we can only repay to
those who come after us."

[427] Mardrus, _Les Mille Nuits_, vol. xvi, p. 158.

[428] Sidney Webb, _Popular Science Monthly_, 1906, p. 526 (previously
published in the _London Times_, Oct. 11, 16, 1906). In Ch. IX of the
present volume it has already been necessary to discuss the meaning of the
term, "morality."

[429] Thus, in Paris, in 1906, in the rich quarters, the birthrate per
1,000 inhabitants was 19.09; in well-to-do quarters, 22.51; and in poor
quarters, 29.70. Here we see that, while the birthrate falls and rises
with social class, even among the poor and least restrained class the