The Abdominal and Pelvic Brain
Byron Robinson, M. D.



The function of the tractus genitalis is: Sensation, ovulation, secretion, absorption, peristalsis, menstruation, gestation.

"We are shaped and fashioned by what we love." - Goethe.

    Menstruation is a regular periodic monthly rhythm of the uterus and oviducts.  In general it begins at the age of 15 and ceases at 45, continues four days, the bloody flow amounting to two ounces and should be painless.
    Menstruation belongs distinctly to the oviducts and uterus.  It is a singular rhythmic action.  It is controlled by the automatic menstrual ganglia situated in the walls of the oviducts and uterus.  These rhythmic little brains manifest themselves to the observer by circulatory change and increased motion.  Menstruation might be named oviductal motion.  By direct observation in the human, and also in animals, I have noted the following condition midway between the monthly periods, or at times far remote from oestrus or rutting: The oviducts and uterus are of quite a pale pink color.  In short, they are not congested, and are in repose.  But at the menstrual period or season of oestrus the oviducts and uterus are congested and in active peristaltic motion.  The oviducts are of a dark blue color from their dilated vessels being filled with blood.  The congestion of the uterus is intense but not so manifest as the oviducts.  The oviducts are swollen, thickened and oedematous.  They are soft and pliable.
    At this time a slight irritation while removing them soon excites them into active peristaltic motion.  After removing such oviducts and placing them in warm (salt) water they will maintain vermicular movements for half an hour by gentle irritation.  I have been able to make these observations in women because I operate at any time in laparotomy, after careful preparation, even if it be in the midst of a menstrual period.  As regards animals I have examined several hundred genitals of recently butchered sows, and the oviductal congestion at the oestrus is more apparent in them than in the woman.  The sow's uterus is also probably more congested.  Observations and experiments indicate that menstruation is a regular, periodical rhythm of a blood-wave in the oviducts and uterus induced by the automatic menstrual ganglia.  The continually moving wave rises to a maximum and sinks to a minimum.  The menstrual wave continues from puberty to the menopause.  It is a nervous phenomenon.
    Ovulation is a progressive, non-periodical process.  It begins before birth and continues until the ovarian tissue is atrophied or worn out.  It is liable to occur at menstruation or oestrus because of the vast blood-supply at that time which hastens the follicle to ripen and burst.  In the lower animals, so far as I can decide, menstruation and ovulation seem to be coincident, i. e., they occur at the same time.  I have examined the cow, dog and sheep, but my observation is especially based on the ovular and menstrual process as seen in the sow.  By the examination of some two hundred and fifty specimens of sow's genitals in all conditions it seems to me that the oestrus of the animal embraces both menstruation and ovulation in one physiologic process at the same time.  But as the scale of animal life ascends, the processes of menstruation and ovulation seem to become more and more divorced.  To my mind, the best animal to begin with is the cow.  In the cow one can see more and more distinct processes with the ovaries and oviducts.  Their separate workings become more apparent.  In the calf, before and after birth, ovulation is very manifest.  But the oviducts and uterus before birth and for a considerable time after, are manifestly quiet and pale and rudimentary, non-functional.  In woman it is my observation that menstruation and ovulation are found distinctly separate from each other.  It is true that ovulation and menstruation may occur together, may be coincident, but that is an accident.  The processes are physiologically separate.  In the woman ovulation has been observed before birth, and I have seen ovulation in a woman of 70, the specimens of which were presented to me by Dr. Burgess of Milwaukee.  Now, of these two great physiologic functions, ovulation is a life-long process.  It begins before birth and ends with ovarian atrophy.  But menstruation is a periodical process beginning with puberty and ending with the menopause.  Puberty must be observed as initiating the new exercise of genital ganglia.  A viscus assumes a new rhythm which disturbs the entire system.
    The views here contained are that menstruation is governed by nervous ganglia situated in the walls of the oviducts and uterus.  I have designated these nervous structures as automatic menstrual ganglia.  As a deduction of this theory, oviductal - motion and oviductal changes will be considered the most marked phenomena of menstruation.  The question may be asked: What is a nervous ganglion?  A nervous ganglion is a collection of nerve cells.  Its constituents are nerve cells and nerve fibers.  It is an ideal nervous center having a central, conducting and peripheral apparatus.  A ganglion is a little brain, a physiological center.  It has the power of receiving sensation and transmitting motion.  It is automatic in itself.  It possesses the power of nourishment and controls secretion.  Reflex action can be demonstrated in it.  What are called motor, sensory, and sympathetic nerve fibers are found in its composition.  The peculiar feature of a nervous ganglion is rhythm.  It performs cyclical movements.  It has a periodic function which continually waxes to a maximum or wanes to a minimum.  It lives a rhythmic life.  Its periods of action vary from a few seconds to a month.  It is beyond the control of the will.
    1.  The proof of the existence of the ganglia in the oviducts and uterus is from analogy.  All hollow viscera have ganglia in their walls.  Histologists have long known that many viscera possess ganglia which have automatic power.  The names of Bidder, Schmidt, Ludwig, Remak Meissner and Auerbach are associated with the discovery and description of these viscera ganglia.
    (a)  I have satisfied myself many a time, in vivisection on dogs and other animals, that the heart has nervous centers or ganglia, which will continue to act independently of their cerebrospinal connection.  It is not only clear that the heart has automatic ganglia, but that nearly all these ganglia are centered in the walls of the auricles.  I have often watched the heart's action gradually die out from apex to base.  We know by experiment that the heart will perform its cycle of contraction independently of its external connection.  These automatic nervous ganglia situated in the wall of the heart keep up its rhythm, its cyclical action, its periodic movements.  They explode oftener than once a second.  I have severed the heart from its attachments in some animals and watched its beating cease, when, if left alone, it would be still forever; but by applying stimulus to the ganglia the heart would again perform its rhythm.  It would beat and explode just the same as when it was connected to the cerebrospinal system.  Hence few observers doubt that the ganglia of Remak, Bidder, Ludwig and Schmidt sustain and control the rhythm of the heart.  One can prove by experiment that there are several ganglia situated in the auricle by cutting pieces out of its wall.  If these pieces are stimulated they will go through a distinct rhythm.
    (b)  A large number of experiments on the intestines of animals (especially the dog) convinced me distinctly that the intestines are endowed with automatic ganglia in a similar manner to the heart.  These ganglia are called the plexus of Auerbach and the plexus of Meissner-Billroth.  If a dog is killed and the abdomen is opened in a room of 75 degrees F., the intestines can be induced to perform peristalsis for an hour after death by tapping them occasionally with a scalpel.  As soon as the intestines are exposed to the air or tapped with the scalpel, they begin to go through wonderful vermicular movements resembling a moving bundle of angle-worms.  I have often demonstrated the peristaltic movement of the intestines more than an hour after death, so that it can be stated that the automatic ganglia of the bowels will perform their rhythm independently of the cerebrospinal center.   In autopsies I have found the intestines invaginated, and from the non-congested and non-inflammatory condition of the intestinal wall I had no doubt the invagination occurred entirely after the patient's death.  The non-inflammatory telescoping of the intestines in dying subjects is called the "invagination of death." It can be perfectly demonstrated in a dog's intestines fifteen to thirty minutes after he is dead.  Hence the nervous bulbs studded over the plexus of Auerbach and the plexus of Messner-Billroth are the automatic ganglia which induce, sustain, and control the rhythm of the intestines.  The vigorous rhythmic exercise or explosion of the intestinal ganglia is what causes colic, and in bowel constriction occurring in patients having thin belly walls I have observed this with perfection.  The intestinal rhythm caused by the ganglia can be beautifully seen in the defecating intestine of a patient on whom colotomy has been performed.
    I have never seen the causation of the very severe pain in angina pectoris very satisfactorily explained.  I would suggest that it is colic of the heart, caused by abnormally vigorous action of the heart's automatic ganglia; that the desperate pain in angina pectoris is due to the excessive exercise or abnormally vigorous, irregular rhythm of the automatic ganglia situated at the base of the heart.  Hence, clinically, no doubt, we see the abnormally vigorous rhythm or irregular rhythm of the heart in what is called neuralgia or spasm of the heart, or angina pectoris.  The ganglia offer the best explanation. Clinically, we see in the intestines the exercise of Auerbach's and Meissner's ganglia in various diseases.

     Fig. 58.  This illustration presents a fragment of the luxuriant nerve supply of the uterus, oviducts and ovaries.

    In colic and also bowel obstruction we see an excessively vigorous, irregular action of the ganglia.  We note an excessively irregular action of the ganglia in the desperate, painful colic of children, which I believe amounts in many cases to an invagination with subsequent spontaneous disinvagination.  It may be noted that irregular action of the bowel ganglia occurs in children where the cerebrum is insufficiently developed to force the ganglia of Meissner and Auerbach into subjection and thus secure a regular rhythm of the intestine.  We also see irregular ganglionic action in the bowel where the cerebrum is diseased and hence has lost a controlling influence.  In chronic constipation, and in the paralysis of the intestine during peritonitis, we see disease of the ganglia producing such loss of power that the ganglia cannot initiate or sustain sufficient peristalsis to expel the bowel contents.
    (c)  The same statement can be made relative to the bladder.  It is supplied with two kinds of nerves.  One kind is the cerebrospinal.  The other kind is the sympathetic nerves, which especially go to the body and summit of the bladder.  These nerves are studded over with ganglia which may be styled automatic vesicular ganglia.  These ganglia are closely associated with the blood-vessels and walls of the bladder, and have an influence in controlling the rhythm of this cyst.  As an example to demonstrate the action of the automatic ganglia in the bladder, I took from a stag weighing fourteen hundred pounds, the bladder, penis and rectum.  Twelve hours after it was contracted quite small.  I then dilated it, and thirty-six hours after it had again contracted smaller than ever and would not contain half a pint of fluid.  This bladder continued its rhythmic action for more than forty hours.  It is not mere elasticity, as one can watch the rhythm of segments.  It can be well demonstrated by injecting its blood-vessels with red fluid and then watching it for a day, when the slow, cyclical rhythm can be plainly seen.  The sacral spinal nerves preponderate at the neck of the bladder and endow it with sensation.  They likely hinder it from rhythm, while the body and summit of the bladder are mainly supplied with sympathetic nerves.  They give it blunt sensation and rhythm.  But the summit and body of the bladder are the parts endowed with ganglia, and they are also the parts endowed with cyclical rhythm.
    If a rubber bag is inserted into the bladder and then filled with fluid, having its external end connected with a mercury gauge, it can be plainly seen that the bladder undergoes intermittent contraction.  It will demonstrate its rhythm.  Clinically, this rhythm can often be observed in retention of urine.  The filling bladder will periodically make vigorous efforts to expel its contents, and the pain felt at those times can be easily mistaken for colic.  Hence the bladder is endowed with automatic vesical ganglia, which are mainly situated in the walls of the body and summit, especially localized along its highways of nutrition (blood and lymph tracts).  These ganglia preside over the rhythm of the bladder.
    (d)  The analogies of the heart, intestines and bladder are quite apparent, and can reasonably be carried to the uterus and oviducts.  They are all hollow organs.  The oviducts and uterus are no exception to the other abdominal viscera.  What is said in this paragraph is the result of examination of over seven hundred uteri, oviducts and ovaries, of woman, cow, pig, sheep and dog.  Some of the examination was carried on during the life of the animal, and in quite a number of cases I noticed the action of the oviducts in the living woman during operation.  Much of the work was done on freshly butchered animals, where the organs were removed before the general muscular twitching had ceased.  My first distinct attention was drawn to the idea that the heart, intestines, uterus and oviducts acted similarly, by observation in the slaughter house.  Dr. C. S. Miller and myself were watching the slaughter and evisceration of a cow weighing fifteen hundred pounds.  The cow was in the eighth month of pregnancy.  The butcher amputated the large uterus, containing the calf, a little above the internal os.  I noticed that the amputated portion of the uterus containing the calf went through a peculiar series of rhythmic motions.  But the interesting scene was the amputated stump left on the body of the cow.  The stump was about six inches long and three inches thick.  This stump performed its peculiar rhythm long after the cow was dead.  It slowly described circles and arcs with diameters varying from an inch to four inches.  Each muscular layer of that thick uterus worked in perfect harmony.  No uterine layer of muscles interfered with any other.  Every part of the uterine stump seemed to work with intelligence or a kind of quasi-judgment during the rhythm.  At one time the circular muscular layer would go through a slow but distinct rhythmic circle before any other muscular layer would begin.  Then, gradually, the longitudinal muscular layer would. begin to act, and the end of the stump would describe a rhythmic cycle and thus it continued to repeat the rhythmic action until we left, an hour after.  During the activity of the stump the most striking example of the action of the two muscular layers of the uterus could be seen, for while one layer worked vigorously the other remained still.  Another striking example to show that the hollow uterus has its own automatic ganglia may be observed by removing the uterus from a cow immediately after death.  The uterus should be that of a multiparous cow, because such have long, thick, tortuous, helicoid arteries.  Now carefully inject the utero-ovarian arteries with red fluid.  Observation will easily detect rhythm in the segments of this uterus for some forty hours after death, in a 75 degree room.  The rhythmic waves that pass over the uterus will shift the fluid from one segment to another, so that the quantity of fluid is not uniform in each segment.  The rhythm sometimes takes place very slowly.  This phenomenon is not elasticity.  But, clinically, the rhythm of the pregnant uterus has been known since the art of obstetrics began.  My purpose here is simply to draw attention to the independent action of the uterus from a cerebrospinal connection, and to show that the uterus has automatic ganglia like other hollow viscera.
    Labor will take place under profound anesthesia.  Children have been expelled from the uteri of dead women.  All this is due to the nerve apparatus of the uterus.  Some Frenchman severed the spinal cord of a pregnant sow below the brain, thus paralyzing all the voluntary muscles which aid in parturition, yet the sow had her pigs.  The uterus drove one fetus into the vagina, but as the abdominal muscles were paralyzed this fetus had to be driven out by the second fetus, which was pushed against the first by the contracting uterus.
    (e)  The oviduct is simply a continuation of the muscular walls of the uterus, but not of the endometrium.  The endometrium seems to be a temporary gland, whose duration of active life is the menstrual period.  The analogy of the hollow oviduct of the intestine or heart is very close.  Nearly all the original work done on this subject was in relation to the oviducts, for I consider them the most important organ in menstruation.  The object of menstruation is to transport an egg from the ovary to the interior of the uterus.  This can be done by a properly prepared oviduct.  It seems to me that menstruation begins and ends in the oviducts, and that the importance of the oviducts overshadows all other organs in menstruation, however, the endometrium is the important prepared nest.  When the oviducts begin their rhythm the girl has arrived at puberty.  Oviductal motion is a sign of womanhood.  When the oviducts begin their cycles it is a heraldic sign that the gland called the endometrium is prepared to nourish an ovum.  The endometric gland is no doubt often prepared to nourish an ovum before the oviductal motion or menstruation, and from the examination of nearly eight hundred ovaries I am fully satisfied that ovulation goes on from before birth until the end of life, or till the germinal epithelium is worn out.  Actual observation of animals convinced me of this.  One can see no changes in the ovary at puberty, except that of increased vascular supply.  I never could find any periodicity, nor signs of it, in the ovulation in the human, cow or sheep.  The ovules simply ripen progressively and burst when they are mature, whether that be at menstruation or at some other time.  I am sure they often burst by mere mechanical accident.  Hence, it does seem that menstruation and ovulation are two different processes. Two statements may then be made relative to an egg being carried into the uterus: First, when the oviduct goes through its menstrual rhythm it may secure an egg, if it happens to be ready and bursts.  Second, the oviduct may secure an egg, if its fimbriated funnel becomes glued on to the ovary at a point where there is a maturing ovum.
    2.  The Proof of the Existence of the Ganglia in the Oviducts from Direct Observation and Experiment. - If an adult female dog is taken and well anesthetized, and the abdomen opened, the short white oviducts can be found just posterior to the kidney, at the abdominal end of the double uterus.  Two important matters will be observed - first, the condition of the oviduct; second, the position of the oviduct.  If the animal is not in rut, which is very analogous to menstruation, the oviducts will be very white, small and still.  They are very much contracted, and the fimbriated end generally lies as far from the ovary as the fimbria ovarica will permit.  In short, in the interoestrual time non-congestion and quiescence mark the oviductal condition.  The condition and position of the oviduct at the period of rut are wonderfully changed.  The oviduct is very much swollen and elongated; it is dark blue from, especially, venous congestion.  The surrounding blood-vessels are enlarged, tortuous and distended.  The oviduct shows convolutions and tortuosities plainer now than at other times.  The oviduct having become longer and thicker, its entire position is changed.  The strip of (muscular) tissue which connects the fimbriated end of the oviduct to the ovary has shortened, and the funnel mouth of the oviduct is closing on to some portion of the ovary.  At the climax of the menstrual rhythm the fimbriated mouth of the oviduct is often glued or cemented on to the ovary by a kind of glairy MUCOUS exudate.  The careful examination of nearly eight hundred oviducts satisfactorily demonstrated to me that the oviducts go through a distinct rhythm at menstruation.  Menstruation is a periodic cycle of the oviducts.  The oviducts go through a peristaltic or vermicular motion exactly analogous to the intestine.  Now. there is only one kind of apparatus which produces a rhythm, and that is a ganglion.  Hence, as the oviducts go through a rhythm, they must be influenced by a ganglion.
    The changes in the oviduct at puberty are as follows: (a) It assumes rhythmic movements; (b) its muscular action increases; (c) its vascularity is much increased; (d) it becomes extended and loses its corkscrew or spiral shape of fetal life; (e) its epithelium becomes ciliated; (f) its gross activity appears mainly at the abdominal end; (g) its lumen becomes filled with fluid.  This fluid is to float the egg or ovum into the uterus.  The cilia whip the fluid in the oviduct into a current, and this wonderful anatomic and physiological canal floats the ovum to the nourishing gland - the endometrium.  The automatic menstrual ganglia during their rhythm produce such changes in the oviduct as will best prepare it to float an egg from the ovary to the uterus.  As the rhythmic peristalsis of the oviduct reaches its climax the oviduct becomes thicker, longer and its caliber wider.  The fimbria ovarica shorten and draw an oviductal funnel over a part of the ovary.  A dry, contracted oviduct with a narrow lumen offers difficulties for the passage of an ovum.  If the epithelium of the oviduct is so altered by disease that it does not secrete fluid, the egg may not be able to float through the oviductal canal, but may become arrested in its passage, causing ectopic pregnancy.  The reason why an egg does not get into a child's uterus is because its oviduct is deficient in motion; the fluid in its interior and the ciliated epithelium are deficient.  The ciliated epithelium whips an egg into the uterus by means of a fluid medium.  The rhythm of the oviducts, caused by the ganglia, prepares them for their function.  This is done by first drawing the mouth of the oviduct over a part of the ovary; and, second, by flooding the lumen of the oviduct with serous fluid.  Of course it will be only accidental that the mouth of the oviduct will cover a matured ovum.  The vast majority ovulate into the peritoneal cavity.  Ovulation is a life-long process, while menstruation, or rather oviductal rhythm, lasts about thirty years.
    The almost entire separation of the oviduct from the ovary is peculiar to the higher animals, and no doubt lessens the chances of excessive reproduction.  In the hen the ovary and oviduct are continuous.  The active explosion of the automatic menstrual ganglia are the most marked at the abdominal end of the oviduct.  By direct experiment it is easy to make the oviducts perform their rhythmic, vermicular movements for half an hour after their removal from the living.  The oviducts of a cow, sheep, dog or pig can be kept moving in a warm medium by stimulating or pinching them, just in the same manner as pinching the heart or tapping the intestines will keep up the movements of those organs in vivisection.  I have made this experiment many times on the normal oviducts of women where they were removed for various causes.  While the operation is progressing one can see the oviducts going through a rhythm from mere manipulation.  As soon as an oviduct is removed, if it be normal, a rhythmic action may be produced by pinching it.  The two muscular layers of the oviduct will work separately before the eye. The external longitudinal muscular layer shortens the oviduct, while the internal circular muscular layer narrows the oviductal lumen.  An oviduct will maintain this rhythmic motion for about half an hour, if pinched or stimulated in a medium (salt water is a very good medium).
    The large range of movement of a human oviduct under stimulation is very marked, and the vigorous manner in which the two muscular layers of the oviduct work is very noticeable.  If the circular layer is well stimulated, it will contract with such vigor as to resemble a pale, contracted band around the point of irritation.  The endometrium may be looked on as a temporary gland, whose duration of life is the child-bearing period.  So the automatic menstrual ganglia which govern the rhythm of the oviducts and uterus, and make fecundation possible are only temporary ganglia, at least so far as function goes.  The automatic menstrual ganglia begin their functional life in the incipient oviductal motion.
    This is not the only organ that acts merely at a definite period of life, though the organs exist anatomically during the whole of life.  The thymus gland is largest at birth.  The thyroid gland becomes most active in girls at about fifteen.  The sebaceous glands of males spring into functional activity at about eighteen.  When the menstrual ganglia of woman begin to cease their functions forever, the sebaceous glands of the face assume an active function, and a beard results.  The salivary glands do not act for three months after birth.  No doubt the facial sebaceous glands existed always, anatomically but not functionally.  It has appeared to me for some time that there exists some relation between the testicles and sebaceous glands in the male, as there does between the automatic menstrual ganglia and sebaceous glands in the female.
    Whether the rut (oestrus) of animals and the menstruation of woman are the same or different processes we will not discuss now.  But the function of the ganglia and their actual rhythmic process would be precisely the same in either case.  In mammals an oviductal rhythm with its associated changes is almost a necessity to transport an ovum from ovary to uterus.  I could not observe any difference between the state of the oviduct and the relation of its mouth. to the ovary in animals in rut and the menstrual process of woman.  The gross anatomy of both processes appeared identical.
Premenstrual Pain. - The pain immediately preceding menstruation is generally not well understood.  I have observed that many gynecologists of the present day attribute the premenstrual pain to the uterus.  They say the pain is due to the mechanical obstruction to the menstrual fluid.  These views may apply to certain cases.  But I maintain that the premenstrual pain is due to an excessive action of the oviducts or a too vigorous rhythm.  The automatic menstrual ganglia are overexcited and act irregularly.  The excessive stimulation arises mainly from the fluid which finds its way into the lumen of the oviduct.  The fluid in the lumen of the oviduct, arising out of its congested state, acts like a foreign body and excites oviductal action.  The ganglia become immoderately excited in oviducts whose lumen is partially or wholly closed.  The vigorous attempts of the oviducts to expel the fluid confined in their lumen produce well-known agonizing pain.  I have examined women with distended oviducts who would repeatedly tell me that the pain excited by the examination would last for hours.  The oviducts were simply excited into peristalsis by irritation of their ganglia.
    Dyspareunia, so frequent in oviductal disease, is not merely a story of pain at the time of connection, but of pain that endures for hours.  Part of the pain is due to trauma of irritable nerves, but the worst pain is caused by setting in motion the vermicular action of the diseased oviduct.  The confined fluid in the oviducts excites them into peristalsis, just as irritating substances excite the intestine into painful peristalsis.  If an intestine, through obstruction, cannot expel its irritating contents, the picture of pain is almost identical with premenstrual pain.  In fact, I have often wondered whether I was dealing with intestinal or oviductal colic.  It must be remembered that muscle, governed by sympathetic ganglia, acts quite differently from muscle governed by spinal nerves.  One is slow and rhythmic, while the other is rapid and more spasmodic.
    The pelvic brain (cervico-uterine ganglion) is a large mass of aggregated sympathetic ganglia situated on each side of the pelvis at the junction of the uterus and cervix.  It doubtless shares with the abdominal brain in originating, sustaining and inhibiting the menstrual rhythm.  The pelvic brain, like the cervical ganglia, or that of Wrisberg, occupies a subordinate position in regard to the abdominal brain.  It is, however, a prevertebral ganglion.  It is not easy to dissect and isolate on account of its white color and resemblance to adjacent tissue.  It is three-quarters of an inch long and one-half an inch wide in some subjects, and is more like a meshwork than the abdominal brain.  Its irregular meshes are pierced by numerous blood and lymph vessels and connective tissue bundles.  No doubt the irritable uterus, which Gooch described seventy-five years ago, is caused in a great measure by an irritable pelvic brain.  A rhythm produced by a ganglion alone is a very delicate mechanism, and it is no wonder that during the many vicissitudes of menstrual life the rhythm becomes disturbed, irregular and refuses to act.  Pressure of the increasing size of the child's head on the cervico-uterine ganglion initiates labor.
    Anatomical. - The distribution of the sympathetic nerve supply and the spinal nerve supply to the uterus and oviducts strengthens the theory of automatic menstrual ganglia.  Anatomists agree that the uterine sympathetic plexus branches off to supply the uterus and oviducts above the point where the sacral spinal nerves join the sympathetic chain.  The sympathetic plexus of nerves with its ganglia supplies the upper portion (body and fundus) of the uterus and the whole of the oviducts, while the sacral spinal nerves mainly go to the cervix.  Now, it is very likely that the (sacral) spinal nerves have little to do with any rhythm or cyclical action.  It is quite probable that they hinder rhythm.
    They would thus influence the cervix to live a steady life.  The ganglia on the sympathetic uterine and oviductal plexus, on the other hand, are possessed of a peculiar property called rhythm, so their ganglia would endow the uterus and oviducts with rhythm.  This agrees with the observation that the body and fundus of the uterus and the oviducts are the main part of the genital tract involved in menstruation, while the cervix and vagina, mainly supplied with spinal nerves, remain fairly still.  The cervix is a mere guard to the uterus, and does not share in menstruation.  These ganglia mainly follow the blood-vessels, and the tortuous helicoid arteries supplying the uterus and oviducts, which, being long, give much space for ganglia to exist.  The ganglia no doubt control blood-supply by regulating the caliber of the artery and the stay of the blood in the veins.
    3.  The microscope, or sometimes a strong lens, will demonstrate the existence of the ganglia on the plexus of nerves going to the uterus and the oviducts.  The nerves show uneveness.  At places they coalesce into masses, and the microscope demonstrates their ganglionic character.  I have frequently been able to trace the nerves showing distinct bulbs on the posterior part of the uterus.  Histologists have some time ago shown that little ganglia exist in the walls of the uteri of animals.  But space forbids further discussion here.  Every visceral organ has its own supply of sympathetic ganglia brought to it on the walls of the blood-vessels.  Each visceral organ requiring it has its own established cycle initiated in primordial life.  The rhythm becomes strengthened by differentiation into special organs, and by repetition.
    It seems to me that knowledge of the various visceral ganglia will render the function of those organs and their diseases more intelligible.  To intelligibly minister to an organ diseased one must know its pathology.  The treatment of any disease comprehends part if not all of its pathology.  To me the action of the heart under varying states and pressure of the blood is more intelligible with some knowledge of the automatic ganglia which control its rhythm and motion.  A knowledge of the functions of the cardiac ganglia clears many an obscure problem and explains the heart's action under varying conditions.  The same may be said of the ganglia of Meissner and Auerbach in rendering intestinal peristalsis intelligible.  So a study of what may be termed the automatic menstrual ganglia will perhaps throw more light on the action of the oviducts and uterus-organs around which woman is built both mentally and physically.  We suggest that the rhythmic function of the endometric gland, its nidation and denidation, should not be neglected as a part of menstruation.
    The ganglia in the uterus and oviducts of woman generally induce a cycle once a month during their functional activity.  The ganglia explode monthly.  In the lower animals the automatic uterine and oviductal ganglia explode in periods which correspond to the cycle of the rut.  It is here concluded that whether rut and menstruation be the same or different processes, they are governed in their rhythm by the automatic uterine and oviductal ganglia.
    Will these automatic ganglia aid in explaining the function of the uterus, oviducts or ovary after surgical or other destructive procedures on any one of the three?  I think they will.  That menstruation is closely connected with the nervous system, and that, too, with the sympathetic (as it has rhythm) is a common observation.  Nerve disturbances disturb menstruation and its rhythm.  A sprain in the wrist has checked menstruation.  I knew a patient who, while menstruating, became frightened by a whistle from a train and did not menstruate for a year.  Sudden changes in temperature will alter its rhythm.  The mere expectation of marriage will occasionally make its rhythm regular.  Marriage, by mental and physical stimulation to the genital apparatus, will often induce regular menstruation.  When the nervous system is impaired in strength by wasting disease, there may not be enough vital energy to induce and sustain menstrual rhythms.  Tubercular girls cease to menstruate.  It is a common observation that fleshy persons have weak resisting powers, and fleshy women often menstruate irregularly.  In a precocious, abnormally developed girl we may see early menstruation.  In pregnancy and nursing, menstruation is arrested because the nervous vitality is expended in nourishment.  The miserable and painful failure of an infantile uterus in menstration is rather from a deficient endometrium.  If vital energies are directed into different channels, or vitality gets to a low ebb, the remaining powers may be insufficient to initiate and sustain the regular menstrual rhythm.  Non-development occurred from insufficient blood.
    From the views entertained in this paper, that menstruation and ovulation are separate processes, and that the automatic ganglia are situated along the oviducts and uterus and probably closely related with the ovary, it would not be expected that removal of the ovaries would always cause menstruation to cease suddenly.  The automatic ganglia of the oviducts and the uterus are still intact and will execute their rhythm.  Many gynecologists testify that this theory agrees with the facts.  Ovaries are extirpated and oviductal motion continues.  However, the destruction of a part of a connected complex organ soon destroys the nice balance, and nourishment of the ganglia would in time deteriorate, and then insufficient nerve vitalitv with lack of ganglionic harmony would fall in starting and maintaining a menstrual rhythm.  Also, it may be considered that the chief, central, sexual organ of woman is the ovary and the uterus and oviducts are appendages of the ovary.  Extirpation of the oviducts would quite effectually aid in arresting menstruation, though not entirely, as many ganglia would remain in the uterine wall.  Yet in the very plan of the machinery the oviduct is no doubt designed to execute more motion than the uterus, which could perform its function while remaining quite still.  By the German gynecologists, during several years' residence abroad, I was informed that a removal of the oviducts in a vast majority of cases caused a rap'd checking of menstruation.  Mr. Lawson Tait writes that the total removal of the oviducts arrests menstruation in 90 per cent of cases.  Is it not strange that an oviduct cut off two inches from the uterus will maintain the rhythm?  Actual cases prove that when only the diseased ovaries are removed from women, with inflammation existing in the oviducts, they are but little helped in their misery.  The active organ in menstruation is the oviduct, and it will execute its rhythm unless removed.  Ligating the oviducts is not a rational method, as it will not check the rhythm.  Nine years ago I began ligating the uterine artery at the neck of the uterus after removing its appendages.  This effectually and immediately checked menstruation and rapidly atrophied the organ.
    Finally, the oviducts and most of the uterus being removed, menstruation will nearly always stop.  The ovary, left without an oviduct, would not sustain menstruation.  Cases are reported where the oviducts and ovaries and most of the uterus were removed, but menstruation continued.  In such cases, no doubt, a sufficient number of automatic ganglia were left to start and sustain a menstrual rhythm.  In such cases I suggest that investigation of total removal of the organs and also of the reality of continued menstruation should be carefully done.  Patients often call any bleeding menstruation.
    The ovary is the central, essential, sexual organ of woman (requisite not only for ovulation but internal secretion) and should be removed for malignancy and grave disease only.
    Other theories have been advanced as to the cause of menstruation.  Dr. Christopher Martin claims that the nerve centers are located in the lumbar cord.  This is doubtless based on the labors of Budge, who located the center of the bladder in the lumbar cord.
    I wish to thank Dr. C. S. Miller, of Toledo, Ohio, who worked long with me on this subject.