The Psychology of Sex (Vol. 1-6). Havelock Ellis
so is the respiration. The spleen is rhythmic, so also the bladder. The uterus constantly undergoes regular rhythmic contractions at brief intervals. The vascular system, down to the smallest capillaries, is acted on by three series of vibrations, and every separate fragment of muscular tissue possesses rhythmic contractility. Growth itself is rhythmic, and, as Malling-Hansen and subsequent observers have found, follows a regular annual course as well as a larger cycle. On the psychic sides attention is rhythmic. We are always irresistibly compelled to impart a rhythm to every succession of sounds, however uniform and monotonous. A familiar example of this is the rhythm we can seldom refrain from hearing in the puffing of an engine. A series of experiments, by Bolton, on thirty subjects showed that the clicks of an electric telephone connected in an induction-apparatus nearly always fell into rhythmic groups, usually of two or four, rarely of three or five, the rhythmic perception being accompanied by a strong impulse to make corresponding muscular movements.[75]
It is, however, with the influence—to some extent real, to some extent, perhaps, only apparent—of cosmic rhythm that we are here concerned. The general tendency, physical and psychic, of nervous action to fall into rhythm is merely interesting from the present point of view as showing a biological predisposition to accept any periodicity that is habitually imposed upon the organism.[76] Menstruation has always been associated with the lunar revolutions.[77] Darwin, without specifically mentioning menstruation, has suggested that the explanation of the allied cycle of gestation in mammals, as well as incubation in birds, may be found in the condition under which ascidians live at high and low water in consequence of the phenomena of tidal change.[78] It must, however, be remembered that the ascidian origin of the vertebrates has since been contested from many sides, and, even if we admit that at all events some such allied conditions in the early history of vertebrates and their ancestors tended to impress a lunar cycle on the race, it must still be remembered that the monthly periodicity of menstruation only becomes well marked in the human species.[79] Bearing in mind the influence exerted on both the habits and the emotions even of animals by the brightness of moonlight nights, it is perhaps not extravagant to suppose that, on organisms already ancestrally predisposed to the influence of rhythm in general and of cosmic rhythm in particular, the periodically recurring full moon, not merely by its stimulation of the nervous system, but possibly by the special opportunities which it gave for the exercise of the sexual functions, served to implant a lunar rhythm on menstruation. How important such a factor may be we have evidence in the fact that the daily life of even the most civilized peoples is still regulated by a weekly cycle which is apparently a segment of the cosmic lunar cycle.
Mantegazza has suggested that the sexual period became established with relation to the lunar period because moonlight nights were favorable to courting,[80] and Nelson remarks that in his experience young and robust persons are subject to recurrent periods of wakefulness at night which they attribute to the action of the full moon. One may perhaps refer also to the tendency of bright moonlight to stir the emotions of the young, especially at puberty, a tendency which in neurotic persons may become almost morbid.[81]
It is interesting to point out that, the farther back we are able to trace the beginnings of culture, the more important we find the part played by the moon. Next to the alteration of day and night, the moon's changes are the most conspicuous and startling phenomena of Nature; they first suggest a basis for reckoning time; they are of the greatest use in primitive agriculture; and everywhere the moon is held to have vast influence on the whole of organic life. Hahn has suggested that the reason why mythological systems do not usually present the moon in the supreme position which we should expect, is that its immense importance is so ancient a fact that it tends, with mythological development, to become overlaid by other elements.[82] According to Seler, Quetzalcouatl and Tezeatlipoca, the two most considerable figures in the Mexican pantheon, are to be regarded mainly as complementary forms of the moon divinity, and the moon was the chief Mexican measurer of time.[83] Even in Babylonia, where the sun was most specially revered, at the earliest period the moon ranked higher, being gradually superseded by the worship of the sun.[84] Although such considerations as these will by no means take us as far back as the earliest appearance of menstruation, they may serve to indicate that the phases of the moon probably played a large part in the earliest evolution of man. With that statement we must at present rest content.
It is possible that the monthly character of menstruation, while representing a general tendency of the human race, always and everywhere prevalent, may be modified in the future. It is a noteworthy fact that among many primitive races menstruation only occurs at long intervals. Thus among Eskimo women menstruation follows the peculiar cosmic conditions to which the people are subjected; Cook, the ethnologist of the Peary North Greenland expedition, found that menstruation only began after the age of nineteen, and that it was usually suppressed during the winter months, when there is no sun, only about one in ten women continuing to menstruate during this period.[85] It was stated by Velpeau that Lapland and Greenland women usually only menstruate every three months, or even only two or three times during the year. On the Faroe Islands it is said that menstruation is frequently absent. Among the Samoyeds, Mantegazza mentions that menstruation is so slight that some travelers have denied its existence. Azara noted among the Guaranis of Paraguay that menstruation was not only slight in amount, but the periods were separated by long intervals. Among the Indians in North America, again, menstruation appears to be scanty. Thus, Holder, speaking of his experience with the Crow Indians of Montana, says: "I am quite sure that full-blood Indians in this latitude do not menstruate so freely as white women, not usually exceeding three days."[86] Among the naked women of Tierra del Fuego, it is said that there is often no physical sign of the menses for six months at a time. These observations are noteworthy, though they clearly indicate, on the whole, that primitiveness in race is a very powerless factor without a cold climate. On the other hand, again, there is some reason to suppose that in Europe there is a latent tendency in some women for the menstrual cycle to split up further into two cycles, by the appearance of a latent minor climax in the middle of the monthly interval. I allude to the phenomenon usually called Mittelschmerz, middle period, or intermenstrual pain.
Since the investigations of Goodman, Stephenson, Van Ott, Reinl, Jacobi, and others, it has been generally recognized that menstruation is a continuous process, the flow being merely the climax of a menstrual cycle, a physiological wave which is in constant flux or reflux. This cycle manifests itself in all a woman's activities, in metabolism, respiration, temperature, etc., as well as on the nervous and psychic side. The healthier the woman is, the less conscious is the cyclic return of her life, but the cycle may be traced (as Hegar has found) even before puberty takes place, while Salerni has found that even in amenorrhœa the menstrual cycle still manifests itself in the temperature and respiration. (Rivista Sperimentale di Freniatria, XXX, fasc. 2–3.)
For a summary of the phenomena of the menstrual cycle, see Havelock Ellis, Man and Woman, fourth ed., revised and enlarged, Ch. XI; "The Functional Periodicity of Women." Cf. Keller, Archives Générales de Médecine, May, 1897; Hegar, Allgemeine Zeitschrift für Psychiatrie, 1901, Heft 2 and 3; Helen MacMurchy, Lancet, Oct. 5. 1901; A. E. Giles, Transactions Obstetrical Society London, vol. xxxix, p. 115, etc.
Mittelschmerz is a condition of pain occurring about the middle of