amenorrhoea 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 the intermenstrual period, either alone or accompanied by a
slight sanguineous discharge, or, more frequently, a
non-sanguineous discharge. (In a case described by Van Voornveld,
the manifestation was confined to a regularly occurring rise of
temperature.) The phenomenon varies, but seems usually to occur
about the fourteenth day, and to last two or three days. Laycock,
in 1840 (_Nervous Diseases of Women_, p. 46), gave instances of
women with an intermenstrual period. Depaul and Guéniot
(_Dictionnaire Encyclopédique des Sciences Médicales_, Art.,
"Menstruation," p. 694) speak of intermenstrual symptoms, and
even actual flow, as occurring in women who are in a perfect
state of health, and constituting genuine "_règles
surnuméraries_." The condition is, however, said to have been
first fully described by Valleix; then, in 18725 by Sir William
Priestley; and subsequently by Fehling, Fasbender, Sorel,
Halliday Croom, Findley, Addinsell, and others. (See, for
instance, "Mittelschmerz," by J. Halliday Croom, _Transactions of
Edinburgh Obstetrical Society_, vol. xxi, 1896. Also, Krieger,
_Menstruation_, pp. 68-69.) Fliess (_Die Beziehungen zwischen
Nase und weiblichen Geschlechts-Organen_, p. 118) goes so far as
to assert that an intermenstrual period of menstrual
symptoms--which he terms _Nebenmenstruation_--is "a phenomenon
well known to most healthy women." Observations are at present
too few to allow any definite conclusions, and in some of the
cases so far recorded a pathological condition of the sexual
organs has been found to exist. Rosner, of Cracow, however, found
that only in one case out of twelve was there any disease present
(_La Gynécologie_, June, 1905), and Storer, who has met with
twenty cases, insists on the remarkable and definite regularity
of the manifestations, wholly unlike those of neuralgia (_Boston
Medical and Surgical Journal_, April 19, 1900). There is no
agreement as to the cause of _Mittelschmerz_. Addinsell
attributed it to disease of the Fallopian tubes. This, however,
is denied by such competent authorities as Cullingworth and Bland
Sutton. Others, like Priestley, and subsequently Marsh (_American
Journal of Obstetrics_, July, 1897), have sought to find the
explanation in the occurrence of ovulation. This theory is,
however, unsupported by facts, and eventually rests on the
exploded belief that ovulation is the cause of menstruation.
Rosner, following Richelet, vaguely attributes it to the diffused
hyperæmia which is generally present. Van de Velde also
attributes it to an abnormal fall of vascular tone, causing
passive congestion of the pelvic viscera. Others again, like
Armand Routh and MacLean, in the course of an interesting
discussion on _Mittelschmerz_ at the Obstetric Society of London,
on the second day of March, 1898, believe that we may trace here
a double menstruation, and would explain the phenomenon by
assuming that in certain cases there is an intermenstrual as well
as a menstrual cycle. The question is not yet ripe for
settlement, though it is fully evident that, looking broadly at
the phenomena of rut and menstruation, the main basis of their
increasing frequency as we rise toward civilized man is increase
of nutrition, heat and sunlight being factors of nutrition. When
dealing with civilized man, however, we are probably concerned
not merely with general nutrition, but with the nervous direction
of that nutrition.

At this stage it is natural to inquire what the corresponding phenomena
are among animals. Unfortunately, imperfect as is our comprehension of the
human phenomena, our knowledge of the corresponding phenomena among
animals is much more fragmentary and incomplete. Among most animals
menstruation does not exist, being replaced by what is known as heat, or
oestrus, which usually occurs once or twice a year, in spring and in
autumn, sometimes affecting the male as well as the female.[87] There is,
however, a great deal of progression in the upward march of the phenomena,
as we approach our own and allied zoölogical series. Heat in domesticated
cows usually occurs every three weeks. The female hippopotamus in the
Zoölogical Gardens has been observed to exhibit monthly sexual excitement,
with swelling and secretion from the vulva. Progression is not only toward
greater frequency with higher evolution or with increased domestication,
but there is also a change in the character of the flow. As Wiltshire,[88]
in his remarkable lectures on the "Comparative Physiology of
Menstruation," asserted as a law, the more highly evolved the animal, the
more sanguineous the catamenial flow.

It is not until we reach the monkeys that this character of the flow
becomes well marked. Monthly sanguineous discharges have been observed
among many monkeys. In the seventeenth century various observers in many
parts of the world--Bohnius, Peyer, Helbigius, Van der Wiel, and
others--noted menstruation in monkeys.[89] Buffon observed it among
various monkeys as well as in the orang-utan. J.G. St. Hilaire and Cuvier,
many years ago, declared that menstruation exists among a variety of
monkeys and lower apes. Rengger described a vaginal discharge in a species
of cebus in Paraguay, while Raciborski observed in the Jardin des Plantes
that the menstrual hæmorrhage in guenons was so abundant that the floor of
the cage was covered by it to a considerable extent; the same variety of
monkey was observed at Surinam, by Hill, a surgeon in the Dutch army, who
noted an abundant sanguineous flow occurring at every new moon, and
lasting about three days, the animal at this time also showing signs of
sexual excitement.[90]

The macaque and the baboon appear to be the non-human animals, in which
menstruation has been most carefully observed. In the former, besides the
flow, Bland Sutton remarks that "all the naked or pale-colored parts of
the body, such as the face, neck, and ischial regions, assume a lively
pink color; in some cases, it is a vivid red."[91] The flow is slight, but
the coloring lasts several days, and in warm weather the labia are much
swollen.

Heape[92] has most fully and carefully described menstruation in monkeys.
He found at Calcutta that the _Macacus cynomolgus_ menstruated regularly
on the 20th of December, 20th of January, and about the 20th of February.
The _Cynocephalus porcaria_ and the _Semnopithecus entellus_ both
menstruated each month for about four days. In the _Macaci rhesus_ and
_cynomolgus_ at menstruation "the nipples and vulva become swollen and
deeply congested, and the skin of the buttocks swollen, tense, and of a
brilliant-red or even purple color. The abdominal wall also, for a short
space upward, and the inside of the thighs, sometimes as far down as the
heel, and the under surface of the tail for half its length or more, are
all colored a vivid red, while the skin of the face, especially about the
eyes, is flushed or blotched with red." In late gestation the coloring is
still more vivid. Something similar is to be seen in the males also.

Distant, who kept a female baboon for some time, has recorded the dates of
menstruation during a year. He found that nine periods occurred during the
year. The average length between the periods was nearly six weeks, but
they occurred more frequently in the late autumn and the winter than in
the summer.[93]

It is an interesting fact, Heape noted, that, notwithstanding
menstruation, the seasonal influence, or rut, still persisted in the
monkeys he investigated.

In the anthropoid apes, Hartmann remarks that several observers have
recorded periodic menstruation in the chimpanzee, with flushing and
enlargement of the external parts, and protrusion of the external lips,
which are not usually visible, while there is often excessive enlargement
and reddening of these parts and of the posterior callosities during
sexual excitement. Very little, however, appears to be definitely known
regarding any form of menstruation in the higher apes. M. Deniker, who has
made a special study of the anthropoid apes, informs me that he has so far
been unable to make definite observations regarding the existence of
menstruation. Moll remarks that he received information regarding such a
phenomenon in the orang-utan. A pair of orang-utans was kept in the Berlin
Zoölogical Gardens some years ago, and the female was stated to have at
intervals a menstrual flow resembling that of women, and during this
period to refrain from sexual congress, which was otherwise usually
exercised at regular intervals, at least every two or three days; Moll
adds, however, that, while his informant is a reliable man, the length of
time that has elapsed may have led him to make mistakes in details. Keith,
in a paper read before the Zoölogical Society of London, has described
menstruation in a chimpanzee; it occurred every twenty-third or
twenty-fourth day, and lasted for three days; the discharge was profuse,
and first appeared in about the ninth or tenth year.[94]

What is menstruation? It is easy to describe it, by its obvious symptoms,
as a monthly discharge of blood from the uterus, but nearly as much as
that was known in the infancy of the world. When we seek to probe more
intimately into the nature of menstruation we are still baffled, not
merely as regards its cause, but even as regards its precise mechanism.
"The primary cause of menstruation remains unexplained"; "the cause of
menstruation remains as obscure as ever"; so conclude two of the most
thorough and cautious investigators into this subject.[95] It is, however,
widely accepted that the main cause of menstruation is a rhythmic
contraction of the uterus,--the result of a disappointed preparation for
impregnation,--a kind of miniature childbirth. This seems to be the most
reasonable view of menstruation; i.e., as an abortion of a decidua.
Burdach (according to Beard) was the first who described menstruation as
an abortive parturition. "The hypothesis," Marshall and Jolly conclude,
"that the entire pro-oestrous process is of the nature of a preparation
for the lodgment of the ovum is in accordance with the facts."[96]
Fortunately, since we are here primarily concerned with its psychological
aspects, the precise biological cause and physiological nature of
menstruation do not greatly concern us.

There is, however, one point which of late years has been definitely
determined, and which should not be passed without mention: the relation
of menstruation to ovulation. It was once supposed that the maturation of
an ovule in the ovaries was the necessary accompaniment, and even cause,
of menstruation. We now know that ovulation proceeds throughout the whole
of life, even before birth, and during gestation,[97] and that removal of
the ovaries by no means necessarily involves a cessation of menstruation.
It has been shown that regular and even excessive menstruation may take
place in the congenital absence of a trace of ovaries or Fallopian
tubes.[98] On the other hand, a rudimentary state of the uterus, and a
complete absence of menstruation, may exist with well-developed ovaries
and normal ovulation.[99] We must regard the uterus as to some extent an
independent organ, and menstruation as a process which arose, no doubt,
with the object, teleologically speaking, of cooperating more effectively
with ovulation, but has become largely independent.[100]

It is sometimes stated that menstruation may be entirely absent
in perfect health. Few cases of this condition have, however,
been recorded with the detail necessary to prove the assertion.
One such case was investigated by Dr. H.W. Mitchell, and
described in a paper read to the New York County Medical Society,
February 22, 1892 (to be found in _Medical Reprints_, June,
1892). The subject was a young, unmarried woman, 24 years of age.
She was born in Ireland, and, until her emigration, lived quietly
at home with her parents. Being then twenty years of age, she
left home and came to New York. Up to that time no signs of
menstruation had appeared, and she had never heard that such a
function existed. Soon after her arrival in New York, she
obtained a situation as a waiting-maid, and it was noticed, after
a time, that she was not unwell at each month. Friends filled her
ears with wild stories about the dreadful effects likely to
follow the absence of menstruation. This worried her greatly, and
as a consequence she became pale and anæmic, with loss of flesh,
appetite, and sleep, and a long train of imaginary nervous
symptoms. She presented herself for treatment, and insisted upon
a uterine examination. This revealed no pathological condition
of her uterus. She was assured that she would not die, or become
insane, nor a chronic invalid. In consequence she soon forgot
that she differed in any way from other girls. A course of
chalybeate tonics, generous diet, and proper care of her general
health, soon restored her to her normal condition. After close
observation for several years, she submitted to a thorough
examination, although entirely free from any abnormal symptoms.
The examination revealed the following physical condition:
Weight, 105 pounds (her weight before leaving Ireland was 130);
girth of chest, twenty-nine and a half inches; girth of abdomen,
twenty-five inches; girth of pelvis, thirty-four and a half
inches; girth of thigh, upper third, twenty inches; heart
healthy, sounds and rhythm perfectly normal; pulse, 76; lungs
healthy; respiratory murmur clear and distinct over every part;
respiration, easy and twenty per minute; the mammæ are well
developed, firm, and round; nipples, small, no areola; her skin
is soft, smooth, and healthy; figure erect, plump, and
symmetrical; her bowels are regular; kidneys, healthy. She has a
good appetite, sleeps well, and in no particular shows any sign
of ill health. The uterine examination reveals a short vagina,
and a small, round cervix uteri, rather less in size than the
average, and projecting very slightly into the vaginal canal.
Depth of uterus from os to fundus, two and a quarter inches, is
very nearly normal. No external sign of abnormal ovaries. She is
a well-developed, healthy young woman, performing all her
physiological functions naturally and regularly, except the
single function of menstruation. No vicarious menstruation takes
the place of the natural function, though she has been watched
very closely during the past two years, nor the least periodical
excitement. It is added that, though the clitoris is normal, the
mons veneris is almost destitute of hair, and the labia rather
undeveloped, while, "as far as is known," sexual instincts and
desire are entirely absent. These latter facts, I may add, would
seem to suggest that, in spite of the health of the subject,
there is yet some concealed lack of development of the sexual
system, of congenital character. In a case recorded by Plant
(_Centralblatt für Gynäkologie_, No. 9, 1896, summarized in the
_British Medical Journal_, April 4, 1896), in which the internal
sexual organs were almost wholly undeveloped, and menstruation
absent, the labia were similarly undeveloped, and the pubic hair
scanty, while the axillary hair was wholly absent, though that of
the head was long and strong.

We may now regard as purely academic the discussion formerly carried on as
to whether menstruation is to be regarded as analogous to heat in female
animals. For many centuries at least the resemblance has been sufficiently
obvious. Raciborski and Pouchet, who first established the regular
periodicity of ovulation in mammals, identified heat and
menstruation.[101] During the past century there was, notwithstanding, an
occasional tendency to deny any real connection. No satisfactory grounds
for this denial have, however, been brought forward. Lawson Tait, indeed,
and more recently Beard, have stated that menstruation cannot be the
period of heat, because women have a disinclination to the approach of the
male at that time.[102] But, as we shall see later, this statement is
unfounded. An argument which might, indeed, be brought forward is the very
remarkable fact that, while in animals the period of heat is the only
period for sexual intercourse, among all human races, from the very
lowest, the period of menstruation is the one period during which sexual
intercourse is strictly prohibited, sometimes under severe penalties, even
life itself. This, however, is a social, not a physiological, fact.

Ploss and Bartels call attention to the curious contrast, in this
respect, between heat and menstruation. The same authors also
mention that in the Middle Ages, however, preachers found it
necessary to warn their hearers against the sin of intercourse
during the menstrual period. It may be added that Aquinas and
many other early theologians held, not only that such intercourse
was a deadly sin, but that it engendered leprous and monstrous
children. Some later theologians, however, like Sanchez, argued
that the Mosaic enactments (such as Leviticus, Ch. XX, v. 18) no
longer hold good. Modern theologians--in part influenced by the
tolerant traditions of Liguori, and, in part, like Debreyne
(_Moechialogie_, pp. 275 et seq.) informed by medical science--no
longer prohibit intercourse during menstruation, or regard it as
only a venial sin.

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.)

[78] Darwin, _Descent of Man_, p. 164.

[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.

[82] Ed. Hahn, _Demeter und Baubo_, p. 23.

[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.

[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.)

[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.

[90] Quoted by Icard, _La Femme_, etc., p. 63.

[91] Bland Sutton, _Surgical Diseases of the Ovaries_, and _British
Gynecological Journal_, vol. ii.

[92] W. Heape, "The Menstruation of _Semnopithecus Entellus_,"
_Philosophical Transactions_, 1894; "Menstruation and Ovulation of
_Macacus Rhesus_," _Philosophical Transactions_, 1897.

[93] W.L. Distant, "Notes on the Chacma Baboon," _Zoölogist_, January,
1897, p, 29.

[94] _Nature_, March 23, 1899.

[95] W. Heape, "The Menstruation of _Semnopithecus Entellus_,"
_Philosophical Transactions_, 1894, p. 483; Bland Sutton, _Surgical
Diseases of the Ovaries_, 1896.

[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