[79] While in the majority of women the menstrual cycle is regular for the individual, and corresponds to the lunar month of 28 days, it must be added that in a considerable minority it is rather longer, or, more usually, shorter than this, and in many individuals is not constant.  Osterloh found a regular type of menstruation in 68 per cent, healthy women, four weeks being the most usual length of the cycle; in 21 per cent, the cycle was always irregular.  See Naecke, “Die Menstruation und ihr Einfluss bei chronischen Psychosen,” Archiv fuer Psychiatrie, 1896, Bd, 28, Heft 1.

[80] Among the Duala and allied negro peoples of Bantu stock dances of markedly erotic character take place at full moon.  Gason describes the dances and sexual festivals of the South Australian blacks, generally followed by promiscuous intercourse, as taking place at full moon. (Journal of the Anthropological Institute, November, 1894, p. 174.) In all parts of the world, indeed, including Christendom, festivals are frequently regulated by the phases of the moon.

[81] It has often been held that the course of insanity is influenced by the moon.  Of comparatively recent years, this thesis has been maintained by Koster (Ueber die Gesetze des periodischen Irreseins und verwandter Nervenzustaende, Bonn, 1882), who argues in detail that periodic insanity tends to fall into periods of seven days or multiples of seven.

[82] Ed. Hahn, Demeter und Baubo, p. 23.

[83] E. Seler, Zeitschrift fuer Ethnologie, 1907, Heft I, p. 39.  And as regards the primitive importance of the moon, see also Frazer, Adonis, Attis, Osiris, Ch.  VIII.

[84] Jastrow, Religion of Babylonia, 1898, pp. 68, 75-79, 461.

[85] Even in England, Barnes has known women of feeble sexual constitution who menstruated only in summer (R.  Barnes, Diseases of Women, 1878, p. 192).

[86] A.B.  Holder, “Gynecic Notes among American Indians,” American Journal of Obstetrics, No. 6, 1892.

[87] In the male, the phenomenon is termed rut, and is most familiar in the stag.  I quote from Marshall and Jolly some remarks on the infrequency of rut:  “‘The male wild Cat,’ Mr. Cocks informs us, (like the stag), ’has a rutting season, calls loudly, almost day and night, making far more noise than the female.’  This information is of interest, inasmuch as the males of most carnivores, although they undoubtedly show signs of increased sexual activity at some times more than at others, are not known to have anything of the nature of a regularly recurrent rutting season.  Nothing of the kind is known in the Dog, nor, so far as we are aware, in the males of the domestic Cat, or the Ferret, all of which seem to be capable of copulation at any time of the year.  On the other hand, the males of Seals appear to have a rutting season at the same time as the sexual season of the female.” (Marshall and Jolly, “Contributions to the Physiology of Mammalian Reproduction,” Philosophical Transactions, 1905, B. 198.)