a. The propagation of offspring and the protection and support of the young and defenseless always involve sacrifice on the part of the parents and the stronger members of the race.
b. Sacrifice made consciously for the race is, in the natural order of things, compensated.
The period of a young man's life from about fifteen to twenty-five years, when he is growing from boyhood to mature adult life, is called the period ofadolescence. The period of adolescence is ushered in by a series of physical and psychical changes which make a well defined initial period calledpuberty. The period of puberty is about two years in length, and in the average case among American boys, covers the period between the fifteenth and seventeenth years, and is completed when the youth can produce fertile semen capable of fertilizing the human ovum. It is now universally recognized, however, that when the youth reaches this point in his development, while he may be called a man, he represents manhood in its lowest terms. He has not reached either a physical or mental development or maturity which justifies him in undertaking the responsibilities incident to procreating his kind. It requires in the average case a period of eight more years to develop the young man to the full stature of adult manhood, possessing his full physical and mental powers and the strength required of one who should assume the responsibilities of parenthood, so that at the age of twenty-five in the average case the young man may be said to havereached this period of complete development and to have finished the adolescent period. We may profitably now consider more in detail some of the changes incident to this most important period.
a.Pilosity.—The human being belongs to the vertebrate class, mammalia, and as a member of that class he possesses over the cutaneous surface of the body, excepting the palms of the hands and soles of the feet, hair follicles which produce the hairy covering typical of mammals. A careful study of the distribution of the hair on the surface of the human body, comparing it with that of the anthropoid apes, demonstrates that the distribution is identical; and the "lay" of the hair in any one region of the human body corresponds exactly with that of the same region in the ape. For example—the hair on the forearm points outward and upward; on the upper arm down-ward and outward and so on throughout in the human and simian types. Every child comes into the world with a coat of rudimentary hair which is shed at once. Aside from the growth of hair on the head, including the brows and the lashes, the skin is quite free from any noticeable growth of hair for months or even years. Beginning at the age ofpuberty, however, the growth of hair is very much accelerated over the whole pilous surface of the body, particularly upon the face, in the axilla and over the pubic region. It is a generally recognized law of biology, that, at the period of sexual development, the hairy mammalian character becomes accentuated. The increase in the growth of hair at this time can have only one interpretation, viz., that the ancestors of man represented a very much higher degree of pilosity than is the case with man at the present time. It is interesting to note in this connection the almost universal attempt of men to rid the face of this hairy growth by various devices, either pulling the beard or shaving it. The origin of this custom of depilation probably dates back to the remote past and has been observed as a custom among both savages and civilized peoples.
b.The Voice.—In all animals the voice plays an important part in sexual and social relations. In many animals the voice seems to have almost no other function than as a sex call, or a communication between mates and between parents and young. The human subject illustrates this general biological principle in the profound changes which the voice undergoes at the time of puberty. These changes in the male subject consist in increasing the depth of the larynx, thereby increasing the length of the vocal cords which inturn modifies the pitch of the voice, usually about an octave, making it not only lower but much more pleasing in quality and greatly increased in volume.
c.Bone, Muscle and Gland.—Of incalculably greater importance than the changes described above though perhaps less noticeable to the casual observer, are those physical changes which the body undergoes during the first half of the period of adolescence. I refer to the growth of bone, of muscles and of those internal organs associated with nutrition.
The first step in these profound physical changes is a rapid growth in height that makes itself manifest about the fifteenth year. It is not at all unusual for a boy to grow from four to six inches in a year. This increase in height is very largely due to a lengthening of the thigh and leg bones. In serial homology with the thigh and leg are the bones of the arm and we find that these are undergoing an increase in length commensurate with the increase of the legs. So the boy outgrows his clothes; his coat sleeves are drawn up half way to his elbows and his trousers half way to his knees. The muscles scarcely keep pace with the bones in their growth, and tend to be flabby and to lack usual tonicity. It is difficult for the youth to hold his back straight and his shoulders back; he is awkward and ungainly in his movements and becomes easily fatigued because of the condition of his muscles.But the muscles follow immediately in their development and rapidly gain volume and tonicity, filling out the arms, legs, back and shoulders with large masses of firm muscular tissue. The growth of these muscle masses changes the dimensions of the youth and he fills out in his girths as rapidly as, in the previous period, he increased in length measurements.
All of this increase in bulk can only be accomplished by increased activity of all the nutritive processes. The appetite is practically insatiable; the boy can eat three square meals in the day and lunches between meals. If he wakes up in the night he is hungry. To accomplish the digestion and absorption of this food material, the alimentary tract throughout, and particularly the stomach is greatly increased in size. To accomplish the distribution of the food (blood) the heart also is increased in size and strength. With increased bulk of muscle and increased quantity of food we have increased oxidation in the tissues. This requires increased respiration, which demand is satisfied by rapid development of the respiratory system. The thorax increases in dimensions in all directions; it becomes deeper, broader and longer. Not only does the thorax become more capacious but also more mobile and more responsive to the varying requirements of the system.
If we are interested in the biology of all thesechanges, we need not go far to discover the natural causes at work to produce them. Nature is preparing in the youth a home builder; it is preparing an individual who can support and protect not only himself, but also a family. This equipment in the case of primitive man must necessarily be one of bone and brawn. While under the conditions of modern society the necessity for bone and brawn is somewhat less marked, the plan of nature is no less evident and no less interesting.
a.Structural Changes.—The external genitals, besides showing the pudendal pilosity referred to above, are all greatly increased in size. The penis is increased in all of its dimensions, the testes become very much increased in size, the scrotum, probably because of the increased weight of the testes, is also lengthened.
b.Functional Changes.—The testes and associated glandular bodies gradually develop the power of forming perfect semen, capable of fertilizing the human ovum. When these organs thus become capable of procreation, the period of puberty is complete.
In this connection it is important to note that the development of the testes produces a profound effect upon both the physical and mental characteristics of the young man. This effect is produced through asubstance formed in the testes and reabsorbed into the body, thus gaining access to the blood where it exerts its mysterious but profound influence. Just how this affects the mind and body will be discussed in detail in a subsequent chapter.
a.Sports.—Most of the higher animals, particularly man, and all races of men, devote a large part of the energies of the adolescent period to sports or games in which individuals contend with each other or teams of individuals contend with opposing teams in games that bring into play the various powers of the neuro-muscular system: such as alertness of all the senses, readiness and correctness of judgment, agility, speed and strength of movement. Sports might be criticised by some because they represent non-productive expenditure of energy. On the other hand, no energy ever expended by man is so highly productive of so precious a material as results from manly athletic sports. The products of these games are the substances consumed by them, paradoxical as that may at first appear. The use of brain, muscle and glands and the consumption of the cell substances of these tissues results in the development of the nerve, muscleand gland cells into a condition larger, better equipped and more responsive than before such use.
Thus, athletic sports, while they make draughts upon the nerves, muscles and glands, develop all of these tissues to a high degree of efficiency. The plan of nature in this instinctive indulgence in sports must be evident. Nature is educating and developing the male animal (man) to the highest possible degree of efficiency, so that sports, instead of being non-productive, lead to the development of structures possessing a high degree of value, not only to the individual, but also to society.
Furthermore, those qualities of mind that are encouraged on the athletic field between contestants in a game are the qualities that in the later serious struggles of life make most for success.
b.Productive Employment.—Hardly less important than the influence of sports is that of productive employment for the adolescent. That the adolescent youth should not be assigned tasks that overtax his physical or mental powers goes without saying, nor should he be assigned tasks that consume so much of his time that he is unable to take an active part with his fellows in field sports. However, experience demonstrates that the youth undergoes a more wholesome all around development if he takes some active part in a productive employment, than if allowed to devoteall of his energies to play. The simple fact that he is held responsible for some duty about the home or the shop develops in the youth not only a knowledge of how to do things and a sympathy with the adults who are devoting their strength largely to similar tasks, but—more important than either of these considerations—these tasks develop in him the ability to accomplish promptly and efficiently some piece of work as a duty—to do it regularly and promptly because it is a duty without any reference to a personal enjoyment in the task. If this important lesson in life is learned during the early adolescent period, it will make the path of life much less rugged than some seem to find it.
Incident to the activities of the athletic field, the youth is brought into more or less intimate contact with fellows of his kind, both of the same and of the opposite sex. While the boy of ten to fifteen delights in the forming of "cliques, gangs and crowds," the boy of seventeen delights equally in widening his circle of acquaintances. The athletic contest gives him an opportunity not only to measure his powers with those of the other young men, but also to win the respect of his young lady acquaintances. There is no doubt but that the approbation of his young lady friends for his prowess and strength as manifested insports, serves as a strong factor in the stimulation of athletic contests and in bringing the sexes together in a purely social capacity.
While in his social relations the young man is seeking points of tangency with those in his own plane, in his religious experience he seeks to come into relation with his God; that is, with the power that exists in the plane above his own. In the researches of Coe and of Starbuck, made several years ago they discovered the following truth and demonstrated it as a general principle:(1) A vast majority of professing Christians acknowledged their allegiance to God during the early part of the adolescent period; and (2) a vanishingly small percentage of professing Christians became so after the age of twenty-five.
The external genitals of the human male consist of the penis and scrotum, the latter containing the testes.
Thepenisof the young man who has completed the stage of puberty consists (1) of the two corpora cavernosa, as they are called, or erectile bodies, called cavernosa because they contain numerous blood sinuses which when filled cause the organ to erect. (2) Between and beneath the corpora cavernosa lies the corpus spongiosum which consists principally of the urethra. Around these three cylindrical bodies there is a sheath of loose connective tissue, outside of which is the skin.
About one inch of the distal end of the organ is differentiated into a sort of head which is called theglansover which, in the young child, the skin is redoubled and called theprepuceor foreskin. The glans is covered and the prepuce is lined by mucous membrane. Over the glans the mucous membrane is red, thin and moist and possesses numerous nerve papillæ. The prepuce, as stated above, usually covers the glans penis in young children and may do so throughout life. It is sometimes adherent to the glans. This isabnormal, and as soon as it is discovered the adhesions should be broken up by a physician. The normal prepuce of the adolescent male should be free from the glans and should be sufficiently loose easily to retract back of the glans, a position it is likely to take in erection. If the prepuce extends half an inch or more beyond the glans penis as a little flap of skin, or if it is constricted at the opening so that it is difficult to clear the glans or to replace the prepuce when it is once back of the glans, the condition is not normal, and should have the attention of a competent surgeon.
One can easily understand the need of a prepuce in the case of primeval man, who was practically unprotected by clothing, but in the present condition of civilized races the prepuce is certainly an unnecessary appendage, and there are several good reasons why the prepuce should be removed. This operation [circumcision] is not, in any sense, to be looked upon as a mutilation, but simply a hygienic measure made advisable, if not necessary, by the unnatural conditions under which we are now existing.
Beneath the prepuce cheesy secretions from the glands back of the head of the penis collect, and if the organ is not frequently cleansed these accumulated secretions may serve as an irritant. Such local irritation is one of the most prevalent causes of masturbation in boys.
The removal of the prepuce in young children is an exceedingly simple operation and not by any means difficult or dangerous in the adult. If the prepuce is removed the organ will need no especial care, as contact with the clothing will remove the secretions as they appear. Furthermore, the glans penis becomes less sensitive and therefore less subject to local irritation thus simplifying the young man's problems in sexual hygiene.
The penis in its flaccid state varies considerably in size, due not only to varying conditions of temperature but also to individual peculiarities. The organ may vary between 2½ inches and 6 inches in length in the flaccid state and between 5 inches and 8 inches in the erected condition. The size of the generative organs is not an index of virility in the male.
Thetestesare the male generative glands and are described as about 1½ inches in length, 1¼ inches in width and nearly 1 inch in thickness. The testes are contained within the scrotal sac, the outside coat of which is a thin wrinkled skin, within which are four thin coats. Next to the testes and enveloping the spermatic cord is a thin covering which is carried down into the scrotum when the testicle leaves the abdomen, where it is formed. This descent of the testes from the abdomen takes place normally in the later weeks of intrauterine life. The testes may, however, through some unusual condition, be retained and make their descent months or even years later. If the testes have not descended by the end of the age of puberty, the advice of a competent surgeon should be sought.
SEMENTESTICULAR CONTRIBUTION.SPERMATOZOASEMINAL GRANULESMUCIN AND WATERVESICULAR CONTRIBUTION.(In quantity greater than all the rest.)ALBUMINALKALINE SALTSWATERPROSTATIC CONTRIBUTION.(Viscid and opalescent.)PROTEINSALKALINE SALTSWATER
Plate IIPlate IIMale Sexual Apparatus
Plate IIMale Sexual Apparatus
The outer coat of the testis is called the tunica albuginea. [See Plate 2.] This tunic or coat sends fibrous partitions into the testis which divide the organ into lobules, each one being conical in shape with the apex directed towards the epididymis, which is that mass of blood vessels and tissues which one can feel on one side of each testis. Within these lobules the spermatozoa are formed by a complex process of cell division and cell germination upon whose description we need not enter here.
Thespermatozoonmay be described as the male sexual cell whose function is to fertilize the female ovum. The spermatozoon is about1/20of an inch in length and consists of a head, body and a vibratile tail. In the human spermatozoon the head is ovoid, appearing pear-shaped or pointed in one view and elliptical in another.
Theepididymisreferred to above, consists of a mass of coiled tubes and blood vessels. After the secretion passes through the tortuous coils of ciliated tubes of the epididymis, it is collected into a single tube called thevas deferens, which passes as a part of the spermatic cord from the scrotum, up through thegroin and over the pubic arch into the pelvic cavity, passing down back of the bladder where it is slightly dilated into anampulla, beyond which the duct is again contracted into a narrow tube, and the two ducts, one from either side, converge and pass into theprostate gland, where they empty into theurethra.
The seminal vesicles.—The seminal vesicles are small bladder-like organs supposed originally to contain the secreted semen collected from the testes. There are two of these vesicles, from each a small duct joins the vas deferens making up what is known as theejaculatory duct. The two ejaculatory ducts coming together in the prostate gland open into the urethra.The seminal vesicles possess glandular walls and secrete the substance which they contain, no part of the secretion of the testes normally finding its way into the vesicles.
The prostate gland, a portion of which is homologous with the female uterus and called uterus masculinus, is situated around the neck of the bladder and is traversed not only by the urethra (prostatic portion), but also by the ejaculatory ducts. There are numerous gland ducts which—collecting the secretion of the prostate gland—open into the urethra in the prostatic portion.
Just beyond the prostate are two small glands calledCowper's Glandswhose ducts enter the urethra some distance beyond the prostate, at the root of the penis.
In the treatment of the physiology of the various structures just described, we may well reverse the order of treatment, thus leading up step by step to a consideration of the more important organs.
a.Urethra.The canal or duct of the penis is called the urethra, and it is important in considering its physiology to remember that it has not only a double function to perform, but that the performance of one function in a measure temporarily unfits it for performance of the other and makes it necessary for a special measure of preparation.
The urinary excretion from the kidneys collecting in the urinary bladder is passed out periodically through the urethra. This same channel must transmit periodically secretions from the sexual apparatus.
b.Cowper's Glandssecrete only under sexual excitement, and usually they secrete only when the sexual excitement reaches a stage which induces an erection. The secretion is composed of a clearalkaline mucus.
The purpose served in the natural economy by this alkaline mucus is a very important one and it is essential that every young man should understand it.
It will be remembered that the male urethra affords passage not only for the urine, but also for thegenerative products. The urine is acid in reaction and the frequent passage of urine along the urethra leaves that duct acid in reaction under usual conditions. The spermatozoa are very sensitive to acid and their vitality is seriously impaired by acid of any kind, particularly the acid of the urine. Nature has provided that the secretion from Cowper's glands should precede the generative products along the urethra, thus neutralizing the acid and insuring for the spermatozoa an alkaline passage from the body.
Besides this important function of the secretion from Cowper's glands, the slimy transparent mucus appearing at the glans penis under sexual excitement serves as a natural lubricant covering the glans of the male organ. A secretion from the female similarly prepares her organs for sexual contact so that the delicate mucous membrane, particularly of the female organs, shall not suffer abrasion.
Many young men have experienced the appearance of the secretion from Cowper's glands and wholly misunderstanding its nature have feared that they were losing some vital fluid. This misunderstanding of the nature of this fluid makes the young man especially subject to the misrepresentations of the advertising quack and charlatan who allege that he is losing vital fluid and will, if not treated, undergo general debility and loss of procreative power. This briefexplanation of the significance of the secretion of Cowper's glands will protect the young man from any such misrepresentations.
c.The Prostate Gland.—That the prostate gland is intimately associated with reproduction is evident from the fact that in those male animals that have suffered castration before puberty, the prostate gland withers and practically disappears. What then is the role that this gland plays? Like Cowper's glands, it secretes only during sexual excitement. Under such excitement its ducts become gorged with a secretion peculiar to it and at the moment of the emission or the ejaculation of the semen the numerous ducts empty their contents into the urethra to be mingled with and made a part of the semen.
The secretion of the prostate is composed of a watery solution of protein and of alkaline salts and so closely similar to the secretion of the seminal vesicles that we will consider its action along with that of the secretion from the vesicles.
d.The Seminal Vesicles.—The seminal vesicles secrete continuously.The secretion is composed of an aqueous solution of albumin and of alkaline salts. This secretion together with the secretion from the prostate gland is poured into the urethra at the moment of sexual orgasm; they become mixed in their transit through the urethra with the secretion from the testes. This mixture is known as semen. [See pg. 42.]
It used to be supposed that the semen was secreted wholly by the testes; that the testes were secreting continuously and that the seminal vesicles were receptacles for the gradually accumulating semen from the testes. The researches of Steinach and others have made the old theory untenable and demonstrate that the semen is a mixture from three distinct sources; that the testicles secrete their contribution to the semen only during sexual stimulation; while the seminal vesicles secreting their products continuously become periodically filled and distended.
Let us inquire regarding the function of this alkaline albuminous secretion from the vesicles and prostate. For what purpose does Nature prepare such a secretion? The spermatozoa frequently remain several days in the organs of the female before the ovum is found and fertilized. During these several days the spermatozoa are exerting no small amount of energy in their vigorous flagellate movement. For such an expenditure of energy they must receive nourishment and stimulation. The nourishment is supplied by the albumin and proteid of the vesicular and prostatic secretions. The stimulation is supplied by the salts also secreted by these glands. The recent researches of Loeb and others have demonstrated the importance of mineral salts in stimulating the activity of living cells. One can cite no better example of this stimulantaction than the influence of these vesicular and prostatic salts upon the activity of the spermatozoa.
The vesicles and prostate may be looked upon as the commissariat of the army of spermatozoa; the vesicles accumulating a stock of supplies to be drawn upon at short notice; the prostate representing a factory where a considerable quantity of supplies can be prepared at short notice.
Thisperiodic distention of the seminal vesiclesis a matter of very considerable hygienic importance and must be thoroughly understood by every young man who would lead a normal sexual life.
These organs in common with all other organs of the body are supplied with two sets of nerves, one set passing away to the spinal cord and carrying messages which indicate the condition of the organ or the presence and character of any local stimulus; the other passing away from the spinal cord to the organ and carrying secretory and motor impulses. The secretory impulses are more or less continuous and as a result, these glands secret continuously and become periodically distended as described above. The motor impulses pass to the muscles within the walls of the vesicles, causing a strong spasmodic contraction of these muscles at the moment of emission of semen, thus throwing the contents of the vesicles into the urethra at the same moment when the epididymis the vasdeferens and the ducts of the prostate are emptying their secreted contents into the urethra.
Now the sensory nerves passing from the seminal vesicles up to the erection and emission centers are stimulated by any unusual pressure within the vesicles. Unusual pressure may be caused either by distention due to accumulated secretion or by pressure upon the vesicles from over-distended rectum or bladder. It sometimes happens that two or more of these influences are acting at the same time. These impulses are most likely to be effective when the subject is asleep, and particularly if he is lying upon his back. The result of the stimulus is to cause an erection, accompanied usually by an erotic dream, the whole phenomenon culminating in an emission of the contents of the seminal vesicles and followed, of course, by a relief of the pressure which was the cause of the condition. This phenomenon has been variously callednocturnal emission, "pollution" and "dreaming-off."
Vecki, a specialist in physiology, hygiene and pathology of the sexual apparatus, says that the nocturnal emission is a normal physiological phenomenon, the object of which is to relieve pressure in the seminal vesicles, and that in normal cases it occurs in fairly regular periods, these periods varying in length with different individuals, according to their physical condition and habits, the period being two to four weeks,usually; though a considerably longer or shorter period would not be looked upon as pathological. Vecki describes the normal nocturnal emission as being accompanied by an erection, erotic dreams, and an orgasm, the subject being wholly unconscious of the condition until he is awakened at the moment of orgasm. Normally, the subject experiences on the following day a feeling of relief and well-being and should, normally, be wholly free from headache, depression or languor.
Inquiry among a large number of normal healthy men convinces the author that it is not at all unusual for these emissions to occur as infrequently as once in two months in normal healthy men. On the other hand, it is not unusual for them to occur as frequently as once in ten days or even once a week and still be within the physiological limit. However, when the emission occurs as frequently as once per week, it should be looked upon as abnormal if it is followed by depression, headache or lassitude. Cases are not unusual in which the nocturnal emission is experienced as often as three times in a week after which there will be a period of two to four weeks without an emission, followed again by very frequent emissions, and a free period. This phenomenon is an individual peculiarity, and is not to be looked upon as abnormal.
Cases of too frequent nocturnal emissions accompanied by languor and headache are usually caused byirritability or lack of tonicity of the sexual apparatus, particularly of the seminal vesicles and the ducts. This irritability and loss of tone is not infrequently caused by masturbation, though it may also be caused by excessive sexual intercourse, making itself manifest, of course, in either case, on cessation of the habit of masturbation or the excessive sexual intercourse.
Another cause of too frequent nocturnal emissions and one wholly separate from any abuse of the sexual function is irritability and mechanical irritation of the sexual apparatus—perhaps especially the membranous and prostatic portion of the urethra—caused by the presence of an excessive amount of oxalates in the urine. Oxalates occur in the urine in sharp angular crystals and would seem to be in a high degree irritating to the tender mucous membrane of the upper part of the urethra. The almost invariable presence of these crystals in excess in those cases that have not been accounted for by abuse of the sexual function leads one to adopt the plausible theory that the crystals are the cause of the irritability. However, we must not lose sight of the fact that these crystals may be simply an accompaniment of the too frequent emissions, and that the presence of oxalates in the urine may be caused by some disturbance in the nutritive processes that go on in the body, which disturbance causes not only the irritability of thesexual apparatus, but also the presence of the crystals.
When the seminal vesicles are much distended it occurs not infrequently that the passage of a hard mass of fecal material through the rectum will, by simple mechanical pressure on the seminal vesicles, force out a few drops, perhaps as much as a teaspoonful, of the contents of the vesicles. This would be called aninvoluntary emission, but the liquid passed out must not be looked upon as semen. It is simply the secretion of the seminal vesicles, and in losing it, one is not losing a vital fluid or a fluid, any portion of which would be reabsorbed; he is simply losing a fluid which would, in the natural course of events, have passed away within the next few days as a nocturnal emission.
These details have been explained in order that the young man may fully understand the physiology of his sexual apparatus and not be disturbed by the advertisements or the pamphlet literature of charlatans who make a business of frightening young men into the belief that in these experiences they are losing "vital fluid"—that they are victims of "lost manhood," or that they are entering into a condition of "general debility" and "impotence." As an actual fact, involuntary loss of vital fluid (spermatorrhea), is a rare case even in the practice of specialists in genito-urinary diseases, and in these rare cases, thecondition is usually a result of very great excesses, sexual debauchery or one of the sequelæ of venereal disease. [Read: Appendix 1, 13 and 17.]
e.Testes.No rational idea of the physiology of the testes can be given without laying down as a fundamental physiological law, thatthe testes secrete under sexual stimulation only. This same general principle applies to all glands, i.e., that they secrete only under the influence of some special stimulation. In harmony with that law, the testes secrete only under the influence of sexual stimulation.
The sexual stimulation may be sub-divided into two general categories, i.e., conscious sexual stimulation and subconscious sexual stimulation.
Conscious sexual stimulationis partly psychical and partly physical. The physical stimulation is produced by physical proximity of a member of the opposite sex. The physical and psychical phases of conscious sexual stimulation are so intimately interwoven that it is exceedingly difficult to discuss one without constant reference to the other, and it may be said in this connection that the psychical attitude of the two individuals of opposite sex who are brought into close physical proximity will modify very greatly their local sexual responses.
Reverting to the lower animals: when a female in rut or heat is brought into proximity to the male,there seems to be on the part of each animal a consciousness of the character and attitude of the other animal and both animals are step by step excited by various physical contacts and probably also psychical conditions to a high state of sexual excitement, leading to the natural ultimate result, coitus, in which event the sexual excitement culminates in the orgasm of the male, which empties the secreted semen into the organs of the female.
It will be easily understood that, in human subjects whose social relations permit them to indulge in coitus, close physical proximity, and various caresses lead, step by step in the normal course of nature to sexual excitement and sexual desire which culminates as described above for the lower animals.
To revert to the function of the testes, we may say that during these various stages of sexual stimulation and excitement the testes are actively secreting thousands upon thousands of nascent spermatozoa, which being released, are hurried along, partly by their own flagellate movements and partly by the action of the cilia in the ducts of the epididymis and the peristaltic contractions of the vas deferens—hurried along the vas to the ampulla. If the period of sexual excitement extends over fifteen to thirty minutes, the whole duct system from the epididymis to the ampulla becomes gorged with the secreted testicular product. Thissecretion consists of active motile spermatozoa, of spermatic granules and of mucus. The latter is secreted by the ducts of the epididymis and the vas deferens, the testicle itself furnishing only spermatozoa, spermatic granules and a small amount of liquid, just sufficient in quantity to float the spermatozoa out of the testes into the ducts.
At the moment of sexual orgasm occurs what is known as, the emission of semen. In this act the whole contents of the ampulla, vas deferens and ducts of the epididymis, the contents of the seminal vesicles, and the contents of the ducts of the prostate gland are all poured out by spasmotic muscular contractions into the urethra and by contraction of the walls of the urethra, ejected from that tube through the mouth of the urethra. Thus, in the act of emission, there is an intimate mixing together of the three contributions to the semen, i.e., thetesticular, vesicular and prostatic.
Sub-conscious Sexual Stimulation.—Sub-conscious sexual stimulation is not accompanied by erection or any mental or physical manifestation of sexual excitement.
When a sexually mature individual is brought into more or less intimate relations with a sexually mature individual of the opposite sex under conditions where the secondary sexual qualities may have free and unrestricted play, there can be no reasonable doubt thatboth individuals experience a sub-conscious sexual stimulation which will influence them both physically and psychically through sub-conscious response of their sexual apparatus. One can easily imagine, for example, that a young man may meet upon the skating rink in winter a young lady for whom he has a very sincere admiration and respect; she on the other hand entertains for him a similar admiration and respect. They may skate together the whole afternoon and converse upon politics, art or philosophy, the young woman feeling herself swung along—almost actually carried on her companion's strong arm. The whole experience is, in the highest degree, pleasurable and exhilarating to her, yet she may be conscious of absolutely no sexual stimulation. On the other hand, the young man experiences most exalted pleasure in the company of his young lady friend—through the pressure of her hand upon his arm, the lithe, graceful movement of body and limbs, the smile, the light in the eye and the soft voice. All of these give him an exquisite pleasure that he will be unable to analyze, even if he were inclined to do so.
In his case, as in the case of the young woman, there has been absolutely no conscious sexual stimulation; in the case of neither individual has there been a thought of sex as such or of their sexual apparatus, yet without a shadow of doubt, the sexual organs ofboth individuals have been more or less active during this period—they have been subject to sub-conscious sexual stimulation.
In the case of the male, his testes have been awakened into an activity of probably considerably less degree than in the case of conscious sexual stimulation, and during this activity of the gland a certain amount of the secretion has been formed.
The most natural question at this point is—What becomes of this secretion? It is not likely that any great number of spermatozoa are released, those that are probably make their way along the vasa deferentia to the ampullæ. The liquid secretion of the testes probably does not leave the testes but is reabsorbed. While there are many features of this mysterious influence of the testes which have never yet been cleared up, this seems certain, that the testes elaborate what may be called an internal secretion, and that the elaboration of this internal secretion is influenced by such stimulation as has just been described above, under the head of sub-conscious sexual stimulation.
Aninternal secretionis a secretion formed by a gland, to be poured into the blood or lymph system, while anexternal secretionis poured out through ducts to the exterior. The thyroid and adrenal glands form internal secretions only, which secretions, poured into the blood and lymph, profoundly affect thenutrition of the body. The salivary glands and gastric glands form external secretions only; which, when poured upon the food, digest it. The liver, pancreas and testes form both external and internal secretions. The external secretion of the testes is that which is poured out in a sexual emission, as described above; the internal secretion of the testes consists of substances formed by the testes of sexually mature individuals, which substances, poured into the blood, profoundly affect the development of the individual and his whole physical and psychical character.