Up to the point to which we have so far considered it, the process of detumescence has been mainly nervous and vascular in character; it has, in fact, been but the more acute stage of a process which has been going on throughout tumescence. But now we reach the point at which a new element comes in: muscular action. With the onset of muscular action, which is mainly involuntary, even when it affects the voluntary muscles, detumescence proper begins to take place. Henceforward purposeful psychic action, except by an effort, is virtually abolished. The individual, as a separate person, tends to disappear. He has become one with another person, as nearly one as the conditions of existence ever permit; he and she are now merely an instrument in the hands of a higher power—by whatever name we may choose to call that Power—which is using them for an end not themselves.
The decisive moment in the production of the instinctive and involuntary orgasm occurs when, under the influence of the stimulus applied to the penis by friction with the vagina, the tension of the seminal fluid poured into the urethra arouses the ejaculatory center in the spinal cord and the bulbo-cavernosus muscle surrounding the urethra responsively contracts in rhythmic spasms. Then it is that ejaculation occurs.[[106]]
"The circulation quickens, the arteries beat strongly," wrote Roubaud in a description of the physical state during coitus which may almost be termed classic; "the venous blood, arrested by muscular contraction, increases the general heat, and this stagnation, more pronounced in the brain by the contraction of the muscles of the neck and the throwing of the head backward, causes a momentary cerebral congestion, during which intelligence is lost and the faculties abolished. The eyes, violently injected, become haggard, and the look uncertain, or, in the majority of cases, the eyes are closed spasmodically to avoid the contact of the light. The respiration is hurried, sometimes interrupted, and may be suspended by the spasmodic contraction of the larynx, and the air, for a time compressed, is at last emitted in broken and meaningless words. The congested nervous centers only communicate confused sensations and volitions; mobility and sensation show extreme disorder; the limbs are seized by convulsions and sometimes by cramps, or are thrown wildly about or become stiff like iron bars. The jaws, tightly pressed, grind the teeth, and in some persons the delirium is carried so far that they bite to bleeding the shoulders their companions have imprudently abandoned to them. This frantic state of epilepsy lasts but a short time, but it suffices to exhaust the forces of the organism, especially in man. It is, I believe, Galen, who said: 'Omne animal post coitum triste præter mulierem gallumque.'"[[107]] Most of the elements that make up this typical picture of the state of coitus are not absolutely essential to that state, but they all come within the normal range of variation. There can be no doubt that this range is considerable. There would appear to be not only individual, but also racial, differences; there is a remarkable passage in Vatsyayana's Kama Sutra describing the varying behavior of the women of different races in India under the stress of sexual excitement—Dravidian women with difficulty attaining erethism, women of the Punjaub fond of being caressed with the tongue, women of Oude with impetuous desire and profuse flow of mucus, etc.—and it is highly probable, Ploss and Bartels remark, that these characterizations are founded on exact observations.[[108]]
The various phenomena included in Roubaud's description of the condition during coitus may all be directly or indirectly reduced to two groups: the first circulatory and respiratory, the second motor. It is necessary to consider both these aspects of the process of detumescence in somewhat greater detail, although while it is most convenient to discuss them separately, it must be borne in mind that they are not really separable; the circulatory phenomena are in large measure a by-product of the involuntary motor process.
With the approach of detumescence the respiration becomes shallow, rapid, and to some extent arrested. This characteristic of the breathing during sexual excitement is well recognized; so that in, for instance, the Arabian Nights, it is commonly noted of women when gazing at beautiful youths whose love they desired, that they ceased breathing.[[109]] It may be added that exactly the same tendency to superficial and arrested respiration takes place whenever there is any intense mental concentration, as in severe intellectual work.[[110]]
The arrest of respiration tends to render the blood venous, and thus aids in stimulating the vasomotor centers, raising the blood-pressure in the body generally, and especially in the erectile tissues. High blood-pressure is one of the most marked features of the state of detumescence. The heart beats are stronger and quicker, the surface arteries are more visible, the conjunctivæ become red. The precise degree of blood-pressure attained during coitus has been most accurately ascertained in the dog. In Bechterew's laboratory in St. Petersburg a manometer was introduced into the central end of the carotid artery of a bitch; a male dog was then introduced, and during coitus observations were made on the blood-pressure at the peripheral and central ends of the artery. It was found that there was a great general elevation of blood-pressure, intense hyperæmia of the brain, rapid alternations, during the act, of vasoconstriction and vasodilatation of the brain, with increase and diminution of the general arterial tension in relation with the various phases of the act, the greatest cerebral vasodilatation and hyperæmia coinciding with the moment following the intromission of the penis; the end of the act is followed by a considerable fall in the blood-pressure.[[111]] I am not acquainted with any precise observations on the blood-pressure in human subjects during detumescence, and there are obvious difficulties in the way of such observations. It is probable, however, that the conditions found would be substantially the same. This is indicated, so far as the very marked increase of blood-pressure is concerned, by some observations made by Vaschide and Vurpas with the sphygmanometer on a lady under the influence of sexual excitement. In this case there was a relationship of sympathy and friendly tenderness between the experimenter and the subject, Madame X, aged 25. Experimenter and subject talked sympathetically, and finally, we are told, while the latter still had her hands in the sphygmanometer, the former almost made a declaration of love. Madame X was greatly impressed, and afterward admitted that her emotions had been genuine and strong. The blood-pressure, which was in this subject habitually 65 millimeters, rose to 150 and even 160, indicating a very high pressure, which rarely occurs; at the same time Madame X looked very emotional and troubled.[[112]]
Some authorities are of opinion that irregularities in the accomplishment of the sexual act are specially liable to cause disturbances in the circulation. Thus Kisch, of Prague, refers to the case of a couple practising coitus interruptus—the husband withdrawing before ejaculation—in which the wife, a vigorous woman, became liable after some years to attacks termed by Kisch neurasthenia cordis vasomotoria, in which there was at daily or longer intervals palpitation, with feelings of anxiety, headache, dizziness, muscular weakness and tendency to faint. He regards coitus as a cause of various heart troubles in women: (1) Attacks of tachycardia in very excitable and sexually inclined women; (2) attacks of tachycardia with dyspnœa in young women, with vaginismus; (3) cardiac symptoms with lowered vascular tone in women who for a long time have practised coitus interruptus without complete sexual gratification (Kisch, "Herzbeschwerden der Frauen verursacht durch den Cohabitationsact," Münchener Medizinisches Wochenschrift, 1897, p. 617). In this connection, also, reference may probably be made to those attacks of anxiety which Freud associates with psychic sexual lesions of an emotional character.
Associated with this vascular activity in detumescence we find a general tendency to glandular activity. Various secretions are formed abundantly. Perspiration is copious, and the ancient relationship between the cutaneous and sexual systems seems to evoke a general activity of the skin and its odoriferous secretions. Salivation, which also occurs, is very conspicuous in many lower animals, as for instance in the donkey, notably the female, who just before coitus stands with mouth open, jaws moving, and saliva dribbling. In men, corresponding to the more copious secretion in women, there is, during the latter stages of tumescence, a slight secretion of mucus—Fürbringer's urethrorrhœa ex libidine—which appears in drops at the urethral orifice. It comes from the small glands of Littré and Cowper which open into the urethra. This phenomenon was well known to the old theologians, who called it distillatio, and realized its significance as at once distinct from semen and an indication that the mind was dwelling on voluptuous images; it was also known in classic times[[113]]; more recently it has often been confused with semen and has thus sometimes caused needless anxiety to nervous persons. There is also an increased secretion of urine, and it is probable that if the viscera were more accessible to observation we might be able to demonstrate that the glands throughout the body share in this increased activity.
The phenomena of detumescence culminate, however, and have their most obvious manifestation in motor activity. The genital act, as Vaschide and Vurpas remark, consists essentially in "a more and more marked tension of the motor state which, reaching its maximum, presents a short tonic phase, followed by a clonic phase, and terminates in a period of adynamia and repose." This motor activity is of the essence of the impulse of detumescence, because without it the sperm cells could not be brought into the neighborhood of the germ cell and be propelled into the organic nest which is assigned for their conjunction and incubation.
The motor activity is general as well as specifically sexual. There is a general tendency to more or less involuntary movement, without any increase of voluntary muscular power, which is, indeed, decreased, and Vaschide and Vurpas state that dynamometric results are somewhat lower than normal during sexual excitement, and the variations greater.[[114]] The tendency to diffused activity of involuntary muscle is well illustrated by the contraction of the bladder associated with detumescence. While this occurs in both sexes, in men erection produces a mechanical impediment to any evacuation of the bladder. In women there is not only a desire to urinate but, occasionally, actual urination. Many quite healthy and normal women have, as a rare accident supervening on the coincidence of an unusually full bladder with an unusual degree of sexual excitement, experienced a powerful and quite involuntary evacuation of the bladder at the moment of orgasm. In women with less normal nervous systems this has, more rarely, been almost habitual. Brantôme has perhaps recorded the earliest case of this kind in referring to a lady he knew who "quand on lui faisait cela elle se compissait à bon escient."[[115]] The tendency to trembling, constriction of throat, sneezing, emission of internal gas, and the other similar phenomena occasionally associated with detumescence, are likewise due to diffusion of the motor disturbance. Even in infancy the motor signs of sexual excitement are the most obvious indications of orgasm; thus West, describing masturbation in a child of six or nine months who practiced thigh-rubbing, states that when sitting in her high chair she would grasp the handles, stiffen herself, and stare, rubbing her thighs quickly together several times, and then come to herself with a sigh, tired, relaxed, and sweating, these seizures, which lasted one or two minutes, being mistaken by the relations for epileptic fits.[[116]]