We have here a remarkable, but not an isolated, example of the tendency of the human mind in its development to rebel against the claims of primitive nature. The whole of religion is a similar remolding of nature, a repression of natural impulses, an effort to turn them into new channels. Prohibition of intercourse during menstruation is a fundamental element of savage ritual, an element which is universal merely because the conditions which caused it are universal, and because--as is now beginning to be generally recognized--the causes of human psychic evolution are everywhere the same. A strictly analogous phenomenon, in the sexual sphere itself, is the opposed attitude in barbarism and civilization toward the sexual organs. Under barbaric conditions and among savages, when no magico-religious ideas intervene, the sexual organs are beautiful and pleasurable objects. Under modern conditions this is not so. This difference of attitude is reflected in sculpture. In savage and barbaric carvings of human beings, the sexual organs of both sexes are often enormously exaggerated. This is true of the archaic European figures on which Salomon Reinach has thrown so much light, but in modern sculpture, from the time when it reached its perfection in Greece onward, the sexual regions in both men and women are systematically minimized.[103] With advancing culture--as again we shall see later--there is a conflict of claims, and certain considerations are regarded as "higher" and more potent than merely "natural" claims. Nakedness is more natural than clothing, and on many grounds more desirable under the average circumstances of life, yet, everywhere, under the stress of what are regarded as higher considerations, there is a tendency for all races to add more and more to the burden of clothes. In the same way it happens that the tendency of the female to sexual intercourse during menstruation[104] has everywhere been overlaid by the ideas of a culture which has insisted on regarding menstruation as a supernatural phenomenon which, for the protection of everybody, must be strictly tabooed.[105] This tendency is reinforced, and in high civilization replaced, by the claims of an æsthetic regard for concealment and reserve during this period. Such facts are significant for the early history of culture, but they must not blind us to the real analogy between heat and menstruation, an analogy or even identity which may be said to be accepted now by most careful investigators.[106] If it is, perhaps, somewhat excessive to declare, with Johnstone, that "woman is the only animal in which rut is omnipresent," we must admit that the two groups of phenomena merge into or replace each other, that their object is identical, that they involve similar psychic conditions. Here, also, we see a striking example of the way in which women preserve a primitive phenomenon which earlier in the zoölogical series was common to both sexes, but which man has now lost. Heat and menstruation, with whatever difference of detail, are practically the same phenomenon. We cannot understand menstruation unless we bear this in mind.
On the psychic side the chief normal and primitive characteristic of the menstrual state is the more predominant presence of the sexual impulse. There are other mental and emotional signs of irritability and instability which tend to slightly impair complete mental integrity, and to render, in some unbalanced individuals explosions of anger or depression, in rarer cases crime, more common;[107] but the heightening of the sexual impulse, languor, shyness, and caprice are the more human manifestations of an emotional state which in some of the lower female animals during heat may produce a state of fury.
The actual period of the menstrual flow, at all events the first two or three days, does not, among European women, usually appear to show any heightening of sexual emotion.[108] This heightening occurs usually a few days before, and especially during, the latter part of the flow, and immediately after it ceases.[109] I have, however, convinced myself by inquiry that this absence of sexual feeling during the height of the flow is, in large part, apparent only. No doubt, the onset of the flow, often producing a general depression of vitality, may tend directly to depress the emotions, which are heightened by the general emotional state and local congestion of the days immediately preceding; but among some women, at all events, who are normal and in good health, I find that the period of menstruation itself is covered by the period of the climax of sexual feeling. Thus, a married lady writes: "My feelings are always very strong, not only just before and after, but during the period; very unfortunately, as, of course, they cannot then be gratified"; while a refined girl of 19, living a chaste life, without either coitus or masturbation, which she has never practiced, habitually feels very strong sexual excitement about the time of menstruation, and more especially during the period; this desire torments her life, prevents her from sleeping at these times, and she looks upon it as a kind of illness.[110] I could quote many other similar and equally emphatic statements, and the fact that so cardinal a relationship of the sexual life of women should be ignored or denied by most writers on this matter, is a curious proof of the prevailing ignorance.[111] This ignorance has been fostered by the fact that women, often disguise even to themselves the real state of their feelings. One lady remarks that while she would be very ready for coitus during menstruation, the thought that it is impossible during that time makes her put the idea of it out of her mind. I have reason to think that this statement may be taken to represent the real feelings of very many women. The aversion to coitus is real, but it is often due, not to failure of sexual desire, but to the inhibitory action of powerful extraneous causes. The absence of active sexual desire in women during the height of the flow may thus be regarded as, in part, a physiological fact, following from the correspondence of the actual menstrual flow to the period of _pro-oestrum_, and in part, a psychological fact due to the æsthetic repugnance to union when in such a condition, and to the unquestioned acceptance of the general belief that at such a period intercourse is out of the question. Some of the strongest factors of modesty, especially the fear of causing disgust and the sense of the demands of ceremonial ritual, would thus help to hold in check the sexual emotions during this period, and when, under the influence of insanity, these motives are in abeyance, the coincidence of sexual desire with the menstrual flow often becomes more obvious.[112] It must be added that, especially among the lower social classes, the primitive belief of the savage that coitus during menstruation is bad for the man still persists. Ploss and Bartels mention that among the peasants in some parts of Germany, where it is believed that impregnation is impossible during menstruation, coitus at that time would be frequent were it not thought dangerous for the man.[113] It has also been a common belief both in ancient and modern times that coitus during menstruation engenders monsters.[114] Notwithstanding all the obstacles that are thus placed in the way of coitus during menstruation, there is nevertheless good reason to believe that the first coitus very frequently takes place at this point of least psychic resistance. When still a student I was struck by the occurrence of cases in which seduction took place during the menstrual flow, though at that time they seemed to me inexplicable, except as evidencing brutality on the part of the seducer. Négrier,[115] in the lying-in wards of the Hôtel-Dieu at Angers, constantly found that the women from the country who came there pregnant as the result of a single coitus had been impregnated at or near the menstrual epoch, more especially when the period coincided with a feast-day, as St. John's Day or Christmas.
Whatever doubt may exist as to the most frequent state of the sexual emotions during the period of menstruation, there can be no doubt whatever that immediately before and immediately after, very commonly at both times,--this varying slightly in different women,--there is usually a marked heightening of actual desire. It is at this period (and sometimes during the menstrual flow) that masturbation may take place in women who at other times have no strong auto-erotic impulse. The only women who do not show this heightening of sexual emotion seem to be those in whom sexual feelings have not yet been definitely called into consciousness, or the small minority, usually suffering from some disorder of sexual or general health, in whom there is a high degree of sexual anæsthesia.[116] The majority of authorities admit a heightening of sexual emotion before or after the menstrual crisis. See e.g., Krafft-Ebing, who places it at the post-menstrual period (_Psychopathia Sexualis_, Eng. translation of tenth edition, p. 27). Adler states that sexual feeling is increased before, during and after menstruation (_Die Mangelhafte Geschlechtsempfindung des Weibes_, 1904, p. 88). Kossmann (Senator and Kaminer, _Health and Disease in Relation to Marriage_, I, 249), advises intercourse just after menstruation, or even during the latter days of the flow, as the period when it is most needed. Guyot says that the eight days after menstruation are the period of sexual desire in women (_Bréviaire de l'Amour Expérimentale_, p. 144). Harry Campbell investigated the periodicity of sexual desire in healthy women of the working classes, in a series of cases, by inquiries made of their husbands who were patients at a London hospital. People of this class are not always skilful in observation, and the method adopted would permit many facts to pass unrecorded; it is, therefore, noteworthy that only in one-third of the cases had no connection between menstruation and sexual feeling been observed; in the other two-thirds, sexual feeling was increased, either before, after, or during the flow, or at all of these times; the proportion of cases in which sexual feeling was increased before the flow, to those in which it was increased after, was as three to two. (H. Campbell, _Nervous Organization of Men and Women_, p. 203.)
Even this elementary fact of the sexual life has, however, been denied, and, strange to say, by two women doctors. Dr. Mary Putnam Jacobi, of New York, who furnished valuable contributions to the physiology of menstruation, wrote some years ago, in a paper on "The Theory of Menstruation," in reference to the question of the connection between oestrus and menstruation: "Neither can any such rhythmical alternation of sexual instinct be demonstrated in women as would lead to the inference that the menstrual crisis was an expression of this," i.e., of oestrus. Dr. Elizabeth Blackwell, again, in her book on _The Human Element in Sex_, asserts that the menstrual flow itself affords complete relief for the sexual feelings in women (like sexual emissions during sleep in men), and thus practically denies the prevalence of sexual desire in the immediately post-menstrual period, when, on such a theory, sexual feeling should be at its minimum. It is fair to add that Dr. Blackwell's opinion is merely the survival of a view which was widely held a century ago, when various writers (Bordeu, Roussel, Duffieux, J. Arnould, etc.), as Icard has pointed out, regarded menstruation as a device of Providence for safeguarding the virginity of women.
FOOTNOTES: [75] Thaddeus L. Bolton, "Rhythm," _American Journal of Psychology_, January, 1894.
[76] It is scarcely necessary to warn the reader that this statement does not prejudge the question of the inheritance of acquired characters, although it fits in with Semon's Mnemic theory. We can, however, very well suppose that the organism became adjusted to the rhythms of its environment by a series of congenital variations. Or it might be held, on the basis of Weismann's doctrine, that the germ-plasm has been directly modified by the environment.
[77] Thus, the Papuans, in some districts, believe that the first menstruation is due to an actual connection, during sleep, with the moon in the shape of a man, the girl dreaming that a real man is embracing her. (_Reports Cambridge Expedition to Torres Straits_, vol. v, p. 206.)
[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 Näcke, "Die Menstruation und ihr Einfluss bei chronischen Psychosen," _Archiv für 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 Nervenzustände_, Bonn, 1882), who argues in detail that periodic insanity tends to fall into periods of seven days or multiples of seven.
[83] E. Seler, _Zeitschrift für Ethnologie_, 1907, Heft I, p. 39. And as regards the primitive importance of the moon, see also Frazer, _Adonis, Attis, Osiris_, Ch. VIII.
[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.)
[88] A. Wiltshire, _British Medical Journal_, March, 1883. The best account of heat known to me is contained in Ellenberger's _Vergleichende Physiologie der Haussaügethiere_, 1892, Band 4, Theil 2, pp. 276-284.
[89] Schurig (_Parthenologia_, 1729, p. 125), gives numerous references and quotations.
[91] Bland Sutton, _Surgical Diseases of the Ovaries_, and _British Gynecological Journal_, vol. ii.
[93] W.L. Distant, "Notes on the Chacma Baboon," _Zoölogist_, January, 1897, p, 29.
[96] T. Bryce and J. Teacher (_Contributions to the Study of the Early Development of the Human Ovum_, 1908), putting the matter somewhat differently, regard menstruation as a cyclical process, providing for the maintenance of the endometrium in a suitable condition of immaturity for the production of the decidua of pregnancy, which they believe may take place at any time of the month, though most favorably shortly before or after a menstrual period which has been accompanied by ovulation.
[97] Robinson, _American Gynecological and Obstetrical Journal_, August, 1905.
[98] Bossi, _Annali di Ostetrica e Ginecologia_, September, 1896; summarized in the _British Medical Journal_, October 31, 1896. As regards the more normal influence of the ovaries over the uterus, see e.g. Carmichael and F.H.A. Marshall, "Correlation of the Ovarian and Uterine Functions," _Proceedings Royal Society_, vol. 79, Series B, 1907.
[99] Beuttner, _Centralblatt für Gynäkologie_, No. 49, 1893; summarized in _British Medical Journal_, December, 1893. Many cases show that pregnancy may occur in the absence of menstruation. See, e.g., _Nouvelles Archives d'Obstétrique et de Gynécologie_, 25 Janvier, 1894, supplement, p. 9.
[100] It is still possible, and even probable, that the primordial cause of both phenomena is the same. Heape (_Transactions Obstetrical Society of London_, 1898, vol. xl, p. 161) argues that both menstruation and ovulation are closely connected with and influenced by congestion, and that in the primitive condition they are largely due to the same cause. This primary cause he is inclined to regard as a ferment, due to a change in the constitution of the blood brought about by climatic influences and food, which he proposes to call gonadin. (W. Heape, _Proceedings of Royal Society_, 1905, vol. B. 76, p. 266.) Marshall, who has found that in the ferret and other animals, ovulation may be dependent upon copulation, also considers that ovulation and menstruation, though connected and able to react on each other, may both be dependent upon a common cause; he finds that in bitches and rats heat can be produced by injection of extract from ovaries in the oestrous state (F.H.A. Marshall, _Philosophical Transactions_, 1903, vol. B. 196; also Marshall and Jolly, id., 1905, B. 198). Cf. C.J. Bond, "An Inquiry Into Some Points in Uterine and Ovarian Physiology and Pathology in Rabbits," _British Medical Journal_, July 21, 1906.
[101] Pouchet, _Théorie de l'Ovulation Spontanée_, 1847. As Blair Bell and Pontland Hick remark ("Menstruation," _British Medical Journal_, March 6, 1909), the repeated oestrus of unimpregnated animals (once a fortnight in rabbits) is surely comparable to menstruation.
[102] Tait, _Provincial Medical Journal_, May, 1891; J. Beard, _The Span of Gestation_, 1897, p. 69. Lawson Tait is reduced to the assertion that ovulation and menstruation 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) has brought forward much evidence in confirmation of this view. It may be added that there is considerable significance in the fact that the erotic hallucinations, which are not infrequently experienced by women under the influence of nitrous oxide gas, are more likely to appear at the monthly period than at any other time. (D.W. Buxton, _Anesthetics_, 1892, p. 61.)
[112] Gehrung considers that in healthy young girls amorous sensations are normal during menstruation, and in some women persist, during this period, throughout life. More usually, however, as menstrual period after menstrual period recurs, without the natural interruption of pregnancy, the feeling abates, and gives place to sensations of discomfort or pain. He ascribes this to the vital tissues being sapped of more blood than can be replaced in the intervals. "The vital powers, being thus kept in abeyance, the amative sensations are either not developed, or destroyed. This, superadded by the usual moral and religious teachings, is amply sufficient, by degrees, to extinguish or prevent such feelings with the great majority. The sequestration as 'unclean,' of women during their catamenial period, as practiced in olden times, had the same tendency." (E.C. Gehrung, "The Status of Menstruation," _Transactions American Gynecology Society_, 1901, p. 48.)
[113] It is possible there may be an element of truth in this belief. Diday, of Lyons, found that chronic urethorrhoea is an occasional result of intercourse during menstruation. Raciborski (_Traité de la Menstruation_, 1868, p. 12), who also paid attention to this point, while confirming Diday, came to the conclusion that some special conditions must be present on one or both sides.
[114] See, e.g., Ballantyne, "Teratogenesis," _Transactions of the Edinburgh Obstetrical Society_, 1896, vol. xxi, pp. 324-25.
[115] As quoted by Icard, _La Femme_, etc., p. 194. I have not been able to see Négrier's work.
[116] I deal with the question of sexual anæsthesia in women in the third volume of these _Studies_: "The Sexual Impulse in Women."
II.
The Question of a Monthly Sexual Cycle in Men--The Earliest Suggestions of a General Physiological Cycle in Men--Periodicity in Disease--Insanity, Heart Disease, etc.--The Alleged Twenty-three Days' Cycle--The Physiological Periodicity of Seminal Emissions during Sleep--Original Observations--Fortnightly and Weekly Rhythms.
For some centuries, at least, inquisitive observers here and there have thought they found reason to believe that men, as well as women, present various signs of a menstrual physiological cycle. It would be possible to collect a number of opinions in favor of such a monthly physiological periodicity in men. Precise evidence, however, is, for the most part, lacking. Men have expended infinite ingenuity in establishing the remote rhythms of the solar system and the periodicity of comets. They have disdained to trouble about the simpler task of proving or disproving the cycles of their own organisms.[117] It is over half a century since Laycock wrote that "the _scientific_ observation and treatment of disease are impossible without a knowledge of the mysterious revolutions continually taking place in the system"; yet the task of summarizing the whole of our knowledge regarding these "mysterious revolutions" is even to-day no heavy one. As to the existence of a monthly cycle in the sexual instincts of men, with a single exception, I am not aware that any attempt has been made to bring forward definite evidence.[118] A certain interest and novelty attaches, therefore, to the evidence I am able to produce, although that evidence will not suffice to settle the question finally.
The great Italian physician, Sanctorius, who was in so many ways the precursor of our modern methods of physiological research by the means of instruments of precision, was the first, so far as I am aware, to suggest a monthly cycle of the organism in men. He had carefully studied the weight of the body with reference to the amount of excretions, and believed that a monthly increase in weight to the amount of one or two pounds occurred in men, followed by a critical discharge of urine, this crisis being preceded by feelings of heaviness and lassitude.[119] Gall, another great initiator of modern views, likewise asserted a monthly cycle in men. He insisted that there is a monthly critical period, more marked in nervous people than in others, and that at this time the complexion becomes dull, the breath stronger, digestion more laborious, while there is sometimes disturbance of the urine, together with general _malaise_, in which the temper takes part; ideas are formed with more difficulty, and there is a tendency to melancholy, with unusual irascibility and mental inertia, lasting a few days. More recently Stephenson, who established the cyclical wave-theory of menstruation, argued that it exists in men also, and is really "a general law of vital energy."[120] Sanctorius does not appear to have published the data on which his belief was founded. Keill, an English, follower of Sanctorius, in his _Medicina Statica Britannica_ (1718), published a series of daily (morning and evening) body-weights for the year, without referring to the question of a monthly cycle. A period of maximum weight is shown usually, by Keill's figures, to occur about once a month, but it is generally irregular, and cannot usually be shown to occur at definite intervals. Monthly discharges of blood from the sexual organs and other parts of the body in men have been recorded in ancient and modern times, and were treated of by the older medical writers as an affliction peculiar to men with a feminine system. (Laycock, _Nervous Diseases of Women_, p. 79.) A summary of such cases will be found in Gould and Pyle (_Anomalies and Curiosities of Medicine_, 1897, pp. 27-28). Laycock (_Lancet_, 1842-43, vols. i and ii) brought forward cases of monthly and fortnightly cycles in disease, and asserted "the general principle that there are greater and less cycles of movements going on in the system, involving each other, and closely connected with the organization of the individual." He was inclined to accept lunar influence, and believed that the physiological cycle is made up of definite fractions and multiples of a period of seven days, especially a unit of three and a half days. Albrecht, a somewhat erratic zoölogist, put forth the view a few years ago that there are menstrual periods in men, giving the following reasons: (1) males are rudimentary females, (2) in all males of mammals, a rudimentary masculine uterus (Müller's ducts) still persists, (3) totally hypospadic male individuals menstruate; and believed that he had shown that in man there is a rudimentary menstruation consisting in an almost monthly periodic appearance, lasting for three or four days, of white corpuscles in the urine (_Anomalo_, February, 1890). Dr. Campbell Clark, some years since, made observations on asylum attendants in regard to the temperature, during five weeks, which tended to show that the normal male temperature varies considerably within certain limits, and that "so far as I have been able to observe, there is one marked and prolonged rise every month or five weeks, averaging three days, occasional lesser rises appearing irregularly and of shorter duration. These observations are only made in three cases, and I have no proof that they refer to the sexual appetite" (Campbell Clark, "The Sexual Reproductive Functions," Psychological Section, British Medical Association, Glasgow, 1888; also, private letters). Hammond (_Treatise on Insanity_, p. 114) says: "I have certainly noted in some of my friends, the tendency to some monthly periodic abnormal manifestations. This may be in the form of a headache, or a nasal hæmorrhage, or diarrhoea, or abundant discharge of uric acid, or some other unusual occurrence. I think," he adds, "this is much more common than is ordinarily supposed, and a careful examination or inquiry will generally, if not invariably, establish the existence of a periodicity of the character referred to."
Dr. Harry Campbell, in his book on _Differences in the Nervous Organization of Men and Women_, deals fully with the monthly rhythm (pp. 270 et seq.), and devotes a short chapter to the question, "Is the Menstrual Rhythm peculiar to the Female Sex?" He brings forward a few pathological cases indicating such a rhythm, but although he had written a letter to the _Lancet_, asking medical men to supply him with evidence bearing on this question, it can scarcely be said that he has brought forward much evidence of a convincing kind, and such as he has brought forward is purely pathological. He believes, however, that we may accept a monthly cycle in men. "We may," he concludes, "regard the human being--both male and female--as the subject of a monthly pulsation which begins with the beginning of life, and continues till death," menstruation being regarded as a function accidentally ingrafted upon this primordial rhythm.
It is not unreasonable to argue that the possibility of such a menstrual cycle is increased, if we can believe that in women, also, the menstrual cycle persists even when its outward manifestations no longer occur. Aëtius said that menstrual changes take place during gestation; in more modern times, Buffon was of the same opinion. Laycock also maintained that menstrual changes take place during pregnancy (_Nervous Diseases of Women_, p. 47). Fliess considers that it is certainly incorrect to assert that the menstrual process is arrested during pregnancy, and he refers to the frequency of monthly epistaxis and other nasal symptoms throughout this period (W. Fliess, _Beziehungen zwischen Nase und Geschlechts-Organen_, pp. 44 et seq.). Beard, who attaches importance to the persistence of a cyclical period in gestation, calls it the muffled striking of the clock. Harry Campbell (_Causation of Disease_, p. 54) has found post-climacteric menstrual rhythm in a fair sprinkling of cases up to the age of sixty.
It is somewhat remarkable that, so far as I have observed, none of these authors refer to the possibility of any heightening of the sexual appetite at the monthly crisis which they believe to exist in men. This omission indicates that, as is suggested by the absence of definite statements on the matter of increase of sexual desire at menstruation, it was an ignored or unknown fact. Of recent years, however, many writers, especially alienists, have stated their conviction that sexual desire in men tends to be heightened at approximately monthly intervals, though they have not always been able to give definite evidence in support of their statements.