The frequent occurrence of pollutions in women, the so-called vulvo-vaginal crises and clitoris-crises, is regarded by Eulenburg as a striking manifestation of sexual neurasthenia in woman; in such cases a lascivious dream is spontaneously followed by a more or less abundant discharge of the clear gelatino-mucous secretion of Bartholin’s glands. In women who masturbate, and in tribadists, a profuse and even violent secretion of these glands is produced by touching the clitoris or the erogenic zones at the entrance to the vagina, close to the orifices of Bartholin’s ducts.
Dyspareunia, the absence of voluptuous sensation in women during coitus, may be referred to three fundamental causes:
1. Insufficient or completely wanting peripheral stimulation of the sensory nerve terminals in the female reproductive canal: in these cases the conducting tracts to the nerve centres never become active.
2. Diminution or cessation of the excitability of the reflex centre in the lumbar enlargement of the spinal cord: this leads to failure of the sensation of ejaculation.
3. Inhibitory influences proceeding from the cerebral cortex whereby voluptuous sensations and perceptions are checked.
The first-named of these etiological influences is in my experience the commonest. Incomplete or quite inadequate stimulation of the sensory nerves of the genital canal may be due to the maladroit performance of copulation on the part of the male, owing to inexperience, or it may depend on gross disproportion in size between the reproductive organs of the man and the woman; in other cases it may be due to disease of the reproductive organs in either sex, influencing unfavourably the sensibility to stimulation of the nerves of the genital canal. Awkward or incomplete performance of coitus may thus lead to failure of voluptuous sensation, and this may ultimately pass into permanent dyspareunia. Temporary dyspareunia is very common in young wives during the first months of married life, ensuing on the pains of defloration; and very gradually gives place to normal voluptuous sensation. It may be one or two years after marriage before the sensation of ejaculation is first experienced. Not infrequently, dyspareunia depends on incomplete potency in the husband, who is incompetent to arouse voluptuous sensation in his wife. For this reason, dyspareunia is common in young women married to elderly men; but is common also, where (as so frequently among Russo-Polish Jews) the men also marry very young, at an age of from sixteen to seventeen years, and where, moreover, the husband has often before marriage impaired his potency by masturbation: finally dyspareunia is common when girls still undeveloped sexually are married to powerfully built men.
Regarding the pathological conditions of the female reproductive organs which counteract the peripheral sensory excitants of voluptuous sensation, we exclude from further consideration the obvious causes, absence and atrophy of the reproductive organs, and senile marasmus. Of prime importance as a cause of the failure of sexual sensibility in the early period of married life must be mentioned inflammation of the fossa navicularis, due to awkward attempts at intercourse. Other causes of deficient sensibility are: complete or partial persistence of the hymen, lesions of the vaginal inlet, acute or chronic vulvitis in consequence of irritating abundant secretion, especially as a sequel of gonorrhœal vaginitis. The last named infective disorder is especially harmful, because Bartholin’s glands are involved in the associated vulvitis. Even after the cure of the vulvitis, permanent dyspareunia may remain. Perineal fissures may result in the stimulant effect of coitus being insufficient, owing to the slight friction possible at the vaginal inlet in these cases. Not less serious sometimes are small, hardly discernible fissures in the vagina. Additional causes of deficient sexual sensibility are recto-vaginal, and vesico-vaginal fistulæ.
The second cause of dyspareunia, diminution or complete lack of irritability of the reflex centre of the lumbar enlargement of the spinal cord, appears to be less frequently operative. We must, however, assume that certain nervous disorders, such as hysteria and pathological changes in the spinal cord, are responsible in this connection. The activity of the lumbar sexual centre appears in women to be normally subject to variation within certain limits; and seems usually to attain its maximum irritability during menstruation. But normally these variations are never so great as to produce in women complete though merely temporary dyspareunia; in this respect offering a marked contrast to what occurs in other animals at other times than the rutting season, and of which every bitch not on heat furnishes an example when she refuses the sexual advances of the dog.
As regards the third causal influence in the production of dyspareunia, the influence of the brain, this, though important, is less frequently in operation. Diseases of the brain, degenerative processes, may constitute a cerebral cause for the failure of sexual sensation. But more frequently, certain cortical perceptions, such as dislike or hatred of the cohabiting male, an ardent passion for some other lover, grief and trouble, exercise inhibitory influences, which render the occurrence of voluptuous pleasure during the sexual act difficult or quite impossible.
A condition like dyspareunia, our knowledge of which depends entirely upon the subjective sensations of the woman concerned, is naturally one regarding whose existence accurate information is difficult to obtain. Very rarely does it happen that women spontaneously approach the physician with complaints of this condition; indeed, in my experience, they do so only when they are sterile, and when they assume, in accordance with the widespread popular belief, that their sterility is connected with the absence of voluptuous sensation during sexual intercourse. More commonly, however, it is the husband who feels it his duty to confide to the medical man the remarkable apathy of his wife in sexual intercourse. But when once the medical man’s attention has been directed to this question, and when he institutes enquiries among his patients in a scientific, passionless manner, one making due allowance for a woman’s modesty, as the moral importance of the subject demands, he will be astonished at the frequency of dyspareunia, and he will find herein the explanation of many obscure phenomena in the life of women. On the other hand, it must never be forgotten that a certain number of women complain of dyspareunia without any justification whatever, in order to arouse interest and sympathy, by representing themselves as unwilling sacrifices on the marital altar: the experienced gynecologist will readily detect the cases in which he is being misinformed; he can, moreover, always check the wife’s statements by conversation with the husband.
The constant sign of dyspareunia is the failure of ejaculation during coitus. We have previously described the muscular contractions which lead to ejaculation of the secretion of Bartholin’s glands and to the expulsion of the uterine and cervical mucus, as reflex actions evoked by the sensory stimulus dependent on friction of the female genital organs. The voluptuous sensation of ejaculation, associated with these muscular contractions, which the woman whose sensibility is normal experiences as the culminating point of her sexual “gratification,” is either quite unknown to a woman affected by dyspareunia, or is experienced by her only in a voluptuous dream, as a pollution, in which the sexual dream-perceptions act as the psychical stimuli by which the reflex discharge is originated. It has repeatedly happened to me, that on enquiring of women suffering from dyspareunia regarding their experience of the sensation of ejaculation, I have been informed that such sensations are known to them only from the descriptions of their female friends, or occasionally from dreams from which they have awakened with a feeling of moisture in the external genitals. Von Krafft-Ebing refers this process to a peristaltic contraction of the muscular fibres of the Fallopian tubes and the uterus, “whereby the tubal and uterine mucus is expressed;” whereas, for my part, I am of opinion, that ejaculation affects in the first place and principally the glands of Bartholin, the secretion of which is expressed by the contraction of the constrictor cunni muscles, and secondarily only affects the cervical glands of the uterus.
As a second sign of dyspareunia, I recognize a remarkably rapid outflow of the male semen from the female genital canal, immediately after coitus (profluvium seminis). The woman thus affected complains, when suitably questioned, that she is unable to retain the semen, and that it flows out of the vagina immediately after ejaculation. The cause of this remarkable phenomenon no doubt lies in the fact, that, owing to the absence of the voluptuous sensation, the reflex contractions of the muscles of the female genital organs, normally accompanying this sensation during intercourse, fail to occur. At the vaginal inlet, in normal conditions, the constrictor cunni muscle contracts, and farther up in the vagina a peristaltic contraction of the circularly disposed muscular fibres of the tunica media occurs: in this way the semen ejaculated into the vagina is for a time retained under a certain pressure. But in the absence of these muscular contractions, as well as of the muscular contraction of the pelvic floor, retention of the semen fails to occur. Cattle-breeders and horse-breeders have made similar observations regarding cows and mares, namely, that these animals are sometimes unable to retain the semen after coitus, and it is suggested that in these cases the animals are not properly on heat. Experienced cattle-breeders recommend in such cases that the retention of the semen should be promoted by douching the root of the tail and the external genitals with cold water. It is well known that by stimulating the peripheral sensory nerves in the neighbourhood of the genital organs, a reflex excitement of the lumbar sexual nerve centre is produced, as is seen, for example, in the practice of flagellation of the buttocks, for the increase of sexual desire.
Passing to the consideration of the pathological changes to be found in the reproductive organs of women suffering from dyspareunia, the nature of these will for the most part be obvious in relation to the etiology of the disorder. Most frequent, in my experience, were chronic inflammatory states of the vulva and of the vaginal and uterine mucous membrane, chronic metritis and parametritis. A very frequent appearance, and one practically characteristic of dyspareunia when of long standing, is a marked total relaxation of the reproductive apparatus. The uterus is extremely mobile, usually retroverted and partially prolapsed, thin, with lax walls, and usually an enlarged cavity; the portio vaginalis is flaccid, and runs to a point; the vagina is roomy; there is marked hypersecretion of the mucous membrane of the entire genital canal; there is great flaccidity of the constrictor cunni and levator ani muscles, and of the perineum. In several women with dyspareunia, I found old unhealed lacerations of the perineum. In some cases, the very small size of the clitoris is noteworthy. In one case amenorrhœa was present with an infantile uterus. In a large proportion of the cases I was able to detect a diminution both of the tactile and algic sensibility of the vaginal mucous membrane. The women were for the most part anæmic; many were extremely obese, and of lymphatic constitution. In some cases, however, no pathological changes whatever could be detected in the reproductive apparatus.
Dyspareunia is a condition which affects a woman’s whole nature, powerfully influences her mental life, and thus gives rise to greater psychical than physical damage. The consciousness of being deprived of the greatest joy of physical love produces great emotional depression, even in a woman by no means sensually inclined, and gives rise to a hypochondriacal state, at times even to melancholia. In other cases, the idea, not infrequently suggested by more happily situated women friends, that the woman herself is not to blame for this condition, has a demoralizing effect upon her, and destroys the happiness of married life. (It has been confessed to me, in isolated cases, that the dyspareunia was relative only.) Apart from this, the absence of sexual gratification gives rise to a series of nervous troubles, presenting either the variable characters of hysteria, or else the symptoms of neurasthenia. Finally, the frequently repeated incomplete coitus, incomplete inasmuch as the woman does not experience the sensation of ejaculation, induces chronic hyperæmia in the female reproductive organs, passing on into blood stasis, and ultimately into chronic inflammatory tissue changes; in this way arise metritis, perimetritis, and parametritis, salpingitis, oöphoritis, disorders of menstruation, menorrhagia, and atypical uterine hæmorrhages. The possibility cannot be disproved, that in this way new-growths of the reproductive organs may also originate. The act of sexual intercourse, which at first may be to the woman a matter of comparative indifference, and in which she plays her part merely from a sense of duty, becomes, in cases of long-standing dyspareunia, something to which she feels a positive dislike, and is recognized by her as the actual cause of the troubles that ensue upon intercourse, such as sacrache, sensations of weight and pressure in the pelvis, strangury, fluor albus, a feeling of exhaustion, etc.
At times, perverse sexual sensation is associated with dyspareunia. Women who find no enjoyment in normal sexual intercourse with a male, sometimes masturbate, sometimes indulge in amor lesbicus, etc.
Of great importance appears to me the relation between dyspareunia and sterility in women. As already pointed out, dyspareunia comes chiefly under medical observation in cases in which it is associated with sterility. The husband, seeking advice concerning his wife’s failure to conceive, complains of her frigidity in sexual intercourse as the probable cause; or the wife comes to seek advice, saying that she never experiences sexual gratification, and that for this reason she has failed to become pregnant. As a matter of actual fact, dyspareunia and sterility are associated with such remarkable frequency, that my own experience leads me to believe in the existence of an etiological connection between the two conditions, at least in a certain proportion of the cases. Among 69 sterile women whom I questioned regarding dyspareunia, the latter condition was present in 26, that is to say, in 38% of the cases. Matthews Duncan reported that of 191 sterile women, 62 did not experience sexual enjoyment. Sexual excitement of the woman during copulation would certainly appear to have a definite bearing upon the occurrence of conception, for we know that by the voluptuous sensation reflex actions are aroused in the genital canal, favouring the retention of semen and its passage through the os to the interior of the uterus, and perhaps also giving rise to reflex changes in the cervical secretion which favour the passage of the spermatozoa into the uterine cavity.
In cases of relative dyspareunia, the influence of this condition in producing sterility is also manifested, the unfaithful wife being impregnated by her lover though she has remained sterile in intercourse with the husband to whom she is indifferent. To dyspareunia of this nature (dependent upon sexual disharmony), we may also refer the sterility of a married pair who have for some time lived together in unfruitful intercourse, whereas, after divorce and the contraction of fresh unions, both the man and the woman prove normally fertile. Such cases have been personally known to me; and similar instances aroused the attention of the natural philosophers of antiquity, for instance, that of Aristotle. The importance of voluptuous sensation in promoting conception is also manifest from the fact that in the majority of women, after the pains of defloration, dyspareunia usually persists for a season during the early period of married life; and, corresponding with this, the first conception is usually deferred for some little time after marriage, to a period corresponding with the awakening of the sensation of ejaculation. In this connection, Courty reports the case of a lady who, although in blooming health, remained sterile during the first fifteen years of her married life; she then gave birth to a child whose father was unquestionably her lover; and after this in succession to two other children whose progenitor was the legal husband. This lady had never experienced voluptuous sensation in intercourse prior to the time of her first conception. Similar circumstances with an even clearer significance have been frequently observed among the lower animals; and Darwin records several striking observations of this character. Taking all the evidence into consideration, we are compelled to regard dyspareunia as a condition capable of causing sterility in women, although the sequence is not an absolutely necessary or invariable one.
In order to excite voluptuous sensation during intercourse, savage races make use of various means, some of which we here transcribe from the work of Ploss-Bartels. In Abyssinia, and on the Zanzibar coast, young girls receive instruction in certain rotary muscular movements known by the name of duk-duk, which they employ during coitus for the increase of sexual pleasure. Many Daiaks perforate the glans penis with a silver needle from above downwards; this needle is kept in place like a seton, until a permanent canal is formed through the glans: in order during coitus to stimulate the woman more powerfully, into this canal, just before coitus, various small articles are inserted, such as little rods of brass, ivory, silver, or bamboo, or silver instruments ending in small bundles of bristles; these project from the surface of the glans, and exercise a more powerful friction of the vagina, thus increasing the sexual pleasure of the woman. Men without such an apparatus are rejected by the women, whilst those who have made several such canals in the glans, and can therefore insert several instruments, are especially sought after and prized by the women. Such an apparatus is known as an ampallang, and in a symbolic manner the woman indicates to a man of her choice her desire that he should make use of one; he finds in his bowl of rice a rolled-up leaf, enclosing a cigarette which represents the size of the desired ampallang. Among the Alfurs of North Celebes, in order to increase the voluptuous pleasure of the woman during intercourse, the men bind round the corona glandis the eyelids of a goat, beset with the eyelashes, thus forming a bristly collar; in Java and in Sunda, before coitus, the men surround the penis with strips of goat-skin, leaving the glans free. In China they wind round the corona glandis torn fragments of a bird’s wing; these also project like bristles and increase the friction. Among the Batta of Sumatra, travelling medicine-men perform an operation by means of which they insert, beneath the skin of the penis, small stones, sometimes to the number of ten, at times also angular fragments of gold or silver; these heal in beneath the skin, and increase the stimulus of coitus for the women. Among the Malays of Borneo the penis is perforated, and some fine brass wire with the ends turned inwards is inserted: before coitus, the sharp ends of the wire are drawn out so as to project from the skin.
In our own part of the world, voluptuaries make use of an india-rubber ring beset with spines, which before coitus is passed over the corona glandis, in order to promote sexual gratification in the woman during intercourse. In cases of diminished potency in the male, in order to produce sufficient sexual excitement in the female by more powerful erection of the penis, various mechanical means are now employed. For instance, in such a partially impotent man, a constricting band of india-rubber may be passed over the root of the penis, whereby the reflux of blood from the corpora cavernosa is hindered, and a more complete and more enduring erection is induced. Elderly men have frequently declared to me that they were well satisfied by the employment of this simple measure, whilst behind their backs, their wives have assured me that the results were far from satisfactory. The apparatus described by Roubaud for the enlargement of the penis is no longer employed. Partially impotent men make use, however, of an instrument known by the name of “schlitten,” made of gold, silver, or white-metal; it consists of two delicate laminæ, united at the base by a metal ring, and at the upper end by an india rubber ring. This small apparatus, which must be made exactly to measure, renders possible the introduction of the imperfectly erect penis into the vagina; it supports the penis, and readily accommodates itself to the change in size of the organ as it slowly becomes erect.
Fertility in women is the basis of the fecundity of a nation, of its growth, its power, and its importance. It is especially the fertility of married women which enters here into consideration, and forms the source of the statistical data of fertility; these are usually obtained by drawing a ratio between the number of marriages contracted in a given period, and the number of children born in the same period.
The fertility of women is a function beginning at an age varying in dependence on many conditions, and undergoing extinction at a definite period of life. It is, in fact, associated with the duration of the sexual life of woman, and, generally speaking, extends from the sixteenth to the fiftieth year of life. Climate, race, constitution, and morbid conditions, influence alike the first appearance of menstruation and the first pregnancy; and as they influence the duration of menstrual activity, so also do they influence the duration of fertility.
In the Bible are recorded numerous instances of the early commencement of fertility. At the present time also, in warm climates we meet with many examples of early motherhood. From the great work of Ploss-Bartels, from which we have already frequently quoted, we extract and summarize the following ethnographical details. Among the wives of the Bosjesman, mothers aged ten are frequently seen; travellers in New Zealand often saw mothers of eleven years, and mothers of the same age among the Samoyedes and in Palestine; mothers of twelve in British Guiana, in Jamaica, among the Schangallas, at Shiraz in Persia, among the Copts in Egypt; mothers aged thirteen in Cuba, among the Sioux and the Dakotas, and in New Caledonia; mothers aged fourteen among the Negroes of Gaboon.
According to the observations of Robertson, of sixty-five Indian women there gave birth for the first time:
| At the age of 10 years | 1 |
| At the age of 11 years | 4 |
| At the age of 12 years | 11 |
| At the age of 13 years | 11 |
| At the age of 14 years | 18 |
| At the age of 15 years | 12 |
| At the age of 16 years | 7 |
| At the age of 17 years | 1 |
Moreover, in the records of European countries, we find numerous instances of very early motherhood. Molitor’s case, a girl nine years old giving birth to a vesicular mole with an embryo; von Haller’s case, pregnancy in the ninth year of life; Carus’ case, pregnancy at the age of eight. Caspar saw a girl in Berlin who became pregnant at the age of twelve, and was delivered of a living child. Rüttel saw a girl nine years of age pregnant. King attended the confinement of a girl who at the time of her delivery was not yet eleven years old. Taylor reports the case of a girl twelve years and six months of age who was then in the last month of pregnancy. Koblanck attended a girl of fourteen who was delivered of a child weighing four and a half pounds.
In most of these cases the premature fertility is followed by a premature cessation of fertility. And there is more or less truth in Bruce’s statement regarding the Arab women in Africa, that those who began to bear children at the age of eleven were seldom still fertile at the age of twenty.
At times we may observe a remarkable extension of fertility beyond the average age, that is, beyond the age of fifty years.
In northern Europe pregnancy at a comparatively advanced age is by no means rare. From the official statistics of Denmark we learn that among 10,000 women, 465 were delivered at ages between 50 and 55 years. In Sweden, of 10,000 mothers, 300 gave birth to children when more than 50 years of age. In Ireland, the proportion of mothers over 50 was 345 per 10,000. In England the official figures dealing with the delivery of 483,613 women, showed that 7,022 were between 45 and 50 years of age, and 167 over 50 years of age.
The Surgical Academy of Paris, in an authoritative statement regarding the late age at which conception could take place, alluded to the fact that Cornelia, of the family of the Scipios, gave birth to Volusius Saturninus when sixty years of age, that the physician Marsa in Venice recorded the existence of pregnancy in a woman of sixty, that de la Motte recorded pregnancy in a woman of fifty-one, and that he believed it to be true that another Parisian woman had given birth to a girl at the age of sixty-three, and had herself suckled the infant.
In an important case, however, which came before the Court of Chancery in England, the court held that there was no definite evidence of the possibility of pregnancy in a woman sixty years of age; but that the greatest age at which, in England, pregnancy had indisputably occurred, was 54.
Among 4,925 deliveries occurring in the Prague Maternity Hospital, Schwing reports that there were 9 women delivered for the first time when over 40 years of age. Of these:
Haller reports the cases of two women who gave birth to children, one at the age of 63, the other at the age of 70 years. Meissner delivered a woman of 60 years of her seventh child; Rush attended the delivery of a woman aged 60; Dewees that of a woman aged 61. Mende and Bernstein report cases of delivery at the age of 60. Marion Sims saw, in the state of Alabama, a negro woman 58 to 60 years of age, who gave birth to a child at this age, at an interval of twenty years since her last pregnancy. Nieden reports a case in which the first pregnancy occurred 26 years after marriage. When married, the wife was 18 years of age, the husband 30; during their first twenty-five years of married life there was no sign of pregnancy, but when the wife was 44 years of age, menstruation, hitherto regular, suddenly ceased; the cause of the cessation proved to be pregnancy, and at term a healthy girl weighing nine pounds was born; the mother was able to nurse the child herself. Smith attended a woman aged 52 who was delivered of twins; the youngest of her eight other children, who were then all living, was ten years of age.
Rodzewitsch collected from the Russian literature of the years 1872 to 1881, eleven cases in which women aged 50 to 55 had given birth to children. Talquist reports that in Finland, in the year 1883, a woman 58 years of age was delivered; whilst Ansell records the case of an Englishwoman who became a mother when 59 years of age. John Kennedy records the case of a woman of 62 who was normally delivered at this age; she had begun to menstruate at the age of 13, and since the age of 20 had previously given birth to 21 children, the last five when she was 47, 49, 51, 53, and 56 years of age, respectively. Prior even reports the case of a woman 72 years of age, who not only menstruated, but had an abortion(!)
The ideal of fertility in women is that the first completed act of sexual intercourse should be followed immediately by conception, that the pregnancy should terminate after the normal lapse of time in the birth of a child, and that the same process should be repeated at intervals of about ten months until the end of active sexual life. In actual experience, however, this never occurs. Fertilization as an immediate consequence of the first act of sexual intercourse (which in the lower animals is regarded as the rule) is a very rare occurrence in human beings. Moreover, in no single marriage is the reproductive capacity of the wife utilized to the full, up to the time of extinction of her generative faculty; either because the potency of the male partner undergoes a gradual decline, or, it may be, because, after a while, sexual intercourse becomes less frequent, or because precautions against procreation are taken.
The number of children to which during the three decades of her sexual life, from the menarche to the menopause, a woman might theoretically give birth, is never actually born. If we assume that, during the period of active sexual life, a woman requires a period of fifteen months to two years for each pregnancy, parturition, and lactation, a woman could easily during this period have fifteen or sixteen children, and this figure would represent the normal product of the normal fertility of the human female. There are indeed, women who, it may be in consequence of an exceptionally long period of sexual activity, or through giving birth repeatedly to twins or triplets, or because they have married several husbands in succession, have given birth to twenty-four children or even more. In Berlin, in the year 1901, there lived a woman 41 years of age who had had 23 children; there were three women, aged respectively 40, 43, and 46 years, who had had each 21 children; 246 women with families numbering 13 to 20; and 169 women each of whom had given birth to 12 children. In the very great majority of cases, however, the fertility of the wife of the present day is never fully developed. It is modified in various ways by the conditions of marriage, by social circumstances, by considerations relating to the health of husband or wife, by actual illnesses, and by voluntary limitation of fertility. Generally speaking, according to the investigations of Quetelet, Sadler, and Finlayson, the fertility of women is greatest in marriages in which the husband is as old as the wife, or a little older, but without marked difference in age. Marriages contracted at a very early age are less fruitful; the highest fertility is found in marriages contracted when the husband is 23 and the wife 26 years of age.
Conception does not generally take place until sexual intercourse has been frequently repeated. As the result of a statistical enquiry of my own, relating to 556 fruitful marriages, I ascertained that in these the first delivery occurred:
Thus we learn that in 35.5% of the cases the first delivery occurred within 1¼ years after marriage; in 15.6% within 10 months; and in 19.9% within 15 months after marriage; and 11.5% of the cases, the first delivery was more than 1¼ years and less than 2 years after marriage; in 6.0% it was between 2 and 3 years after marriage; and in 2.6%, the first delivery did not occur until more than 3 years after marriage.
From examination of the birth registers of Edinburgh and Glasgow, Matthews Duncan determined the mean interval between marriage and the birth of a living child to be seventeen months. In the majority of cases, the first delivery does not occur until a complete year has elapsed since marriage; in fact, in nearly two-thirds of the instances the first delivery occurs during the second year of married life.
The interval between two successive births is, according to Matthews Duncan, on the average 18 to 24 months, according to Goehlert, 24 to 26 months; the latter, however, points out that in cases in which the child dies very soon after birth, the birth of the next child ensues on the average in 16 to 18 months. In this connection, we must not fail to take into consideration the influence of lactation, inasmuch as mothers who do not suckle their children become pregnant considerably earlier, on the average, than those who undertake this duty. In reigning families, for instance, it is by no means uncommon for the consort to be delivered twice within a single year. The degree to which lactation hinders conception is so widely known, that women often suckle their infant for a very long period, with the definite aim of preventing the speedy recurrence of pregnancy. A high official from the Dutch Indies informed me that for this reason the native women were accustomed to suckle their infants for several years, and that it was by no means uncommon to see a small boy running about smoking a cigar, and then hurrying to his mother in order to be suckled.
The age at which a woman contracts marriage has also to this extent an influence upon her fertility, inasmuch as it appears that those who marry very young are far less fertile than those who marry between the ages of 20 and 25 years; the latter moreover have, on the average, a shorter time to wait for their first conception than women who marry before the age of 20. Women who marry after the age of 25 have to wait longer after marriage for their first delivery; in fact the older the woman after 25, the greater, on the average, the interval between marriage and the first delivery.
Arranging the data already referred to, regarding 556 fruitful women, in relation to this point of view, it appears that the first birth ensued:
| Within 10 months of marriage. | 10 to 15 months after marriage. | 15 months to 2 years after marriage. | 2 to 3 years after marriage. | More than 3 years after marriage. | |
|---|---|---|---|---|---|
| In 163 women marrying at ages 15 to 20 years | 36 | 53 | 46 | 18 | 10 |
| In 313 women marrying at ages 20 to 25 years | 98 | 113 | 56 | 32 | 14 |
| In 70 women marrying at ages 25 to 33 years | 18 | 30 | 12 | 9 | 1 |
| In 10 women marrying at ages over 33 years | 4 | 3 | 1 | 1 | 1 |
To give percentages, the first birth occurred,
| Within 10 months of marriage. | 10 to 15 months after marriage. | 15 months to 2 years after marriage. | 2 to 3 years after marriage. | More than 3 years after marriage. | |
|---|---|---|---|---|---|
| Women marrying at ages 15 to 20 years, in | 22.0% | 32.5% | 28.2% | 11.0% | 8.1% |
| Women marrying at ages 20 to 25 years, in | 31.3% | 36.1% | 17.8% | 10.2% | 4.4% |
| Women marrying at ages 25 to 33 years, in | 25.7% | 42.8% | 17.1% | 12.8% | 1.4% |
| Women marrying at ages over 33 years, in | 40.0% | 30.0% | 10.0% | 10.0% | 10.0% |
Thus whereas in women who contracted marriage between the ages of 15 and 20 years, only 54.5% were confined for the first time within 15 months after marriage, in women who contracted marriage between the ages of 20 and 25 years, in 67.4% the first delivery occurred within 15 months of marriage. And whereas in those who married at the earlier age, the percentage of first deliveries occurring between 15 months and 2 years after marriage was 28.2, in those who married between the ages of 20 and 25, the percentage of first deliveries after the stated interval was only 17.8.
The figures compiled by Whitehead and Pfannkuch give similar results. Of 700 women who married between the ages of 15 to 20 years, there were 306 only who gave birth to a child within the first two years after marriage; whereas of 1,835 women who married between the ages of 20 and 25 years, no less than 1,661 gave birth to a child within two years after marriage—a percentage of 43.7 in the former case, and 90.6 in the latter case. Pfannkuch, as the result of a very large collection of figures relating to this question, found that in women marrying before the age of 20 years, the average number of months before the first delivery was 26; whereas in women marrying after the age of 20 years, the average number of months before the first delivery was 20.
According to Matthews Duncan
| Of Every 100 Women Who Marry | There Become Mothers | |
|---|---|---|
| In the 1st year of married life. | In the 2d year of married life. | |
| Between the ages of 15 and 20 years | 13.71 | 43.70 |
| Between the ages of 20 and 25 years | 18.48 | 90.51 |
| Between the ages of 25 and 30 years | 12.41 | 75.80 |
| Between the ages of 30 and 35 years | 11.44 | 62.93 |
| Between the ages of 35 and 40 years | 9.27 | 40.97 |
Sadler examined the relationship between the age at which marriage was contracted and the number of offspring in the case of the wives of English peers. He obtained the following results:
| Age at marriage. | Births per marriage. |
|---|---|
| 12 to 16 years | 4.40 |
| 16 to 20 years | 4.63 |
| 20 to 24 years | 5.21 |
| 24 to 28 years | 5.43 |
From exact statistical data of births in the Scandinavian countries of Europe (Denmark, Sweden and Norway), Goehlert compiled the following table, showing the percentages of fertility at various ages:
| Ages. | Married Women. | Unmarried Women. | ||||
|---|---|---|---|---|---|---|
| Denmark. | Sweden. | Norway. | Denmark. | Sweden. | Norway. | |
| Under 20 years. | 1.0 | 1.0 | 0.7 | 9.1 | 7.0 | 4.9 |
| From 20 to 25 years. | 13.9 | 12.8 | 11.9 | 43.9 | 35.1 | 37.0 |
| From 25 to 30 years. | 26.5 | 24.7 | 24.7 | 28.1 | 27.9 | 32.4 |
| From 30 to 35 years. | 26.7 | 26.1 | 25.3 | 11.4 | 16.8 | 14.9 |
| From 35 to 40 years. | 21.0 | 21.6 | 21.3 | 5.4 | 9.0 | 7.1 |
| From 40 to 45 years. | 9.9 | 12.0 | 13.0 | 2.1 | 4.2 | 3.7 |
| Over 45 years. | 1.1 | 1.8 | 3.1 | |||
From this table it appears that the fertility of married women increases steadily up to the age of 35 years, but after this age it begins to decline. What a marked influence the age at marriage has upon fertility is shown by the comparison of the figures relating to married women with those relating to unmarried women; the fertility of unmarried mothers attains its maximum at the ages of 20 to 25 years. In the countries under consideration the average age of women at the time of marriage is 25 to 27 years.
In order to obtain a still clearer picture of the fertility of women in relation to age, Goehlert has combined the figures relating to the married and the unmarried, and then calculated the percentages, with the following results:
| Ages. | Married and Unmarried Women. | ||
|---|---|---|---|
| Denmark. | Sweden. | Norway. | |
| Under 20 years. | 1.7 | 1.6 | 1.1 |
| From 20 to 25 years. | 16.6 | 15.1 | 14.1 |
| From 25 to 30 year | 26.6 | 25.0 | 25.3 |
| From 30 to 35 years. | 25.3 | 25.1 | 24.4 |
| From 35 to 40 years. | 19.6 | 20.4 | 20.0 |
| From 40 to 45 years. | 9.2 | 11.2 | 12.2 |
| From 45 to 50 years. | 1.0 | 1.6 | 2.9 |
| Over 50 years. | |||
If, finally, we combine into a single table the figures relating to all three of these countries, we obtain the following results:
| Under 20 years | 1.5% |
| From 20 to 25 years | 15.3% |
| From 25 to 30 years | 25.6% |
| From 30 to 35 years | 24.9% |
| From 35 to 40 years | 20.0% |
| From 40 to 45 years | 10.9% |
| Over 45 years | 1.8% |
From these figures it appears that the maximum fertility of married women is attained, in Denmark at the age of 31, in Norway at the age of 31.7, and in Sweden at the age of 32 years. In the case of unmarried women, the maximum fertility is at the ages of 24 to 26 years. In the Austrian Empire, the maximum fertility of women is attained at about the age of 30 years; in England it is attained between the ages of 20 and 25 years.
Divergent results as regards the fertility of married women at different ages were obtained by Goehlert from the examination of 5,290 cases from the reigning families of Europe. In the favourable position as regards means of subsistence occupied by the members of these families, marriage naturally occurs, in most cases, much earlier in life, the mean age at marriage being between 19 and 22 years—the youngest mother (in the Capet dynasty) was only 13 years of age—and for this reason the figures relating to the younger age-classes are larger than in the previous tables. But as a result of this, the reproductive capacity also undergoes an earlier extinction, so that of these women, not one gave birth to a child when she was over 50 years of age. Goehlert gives the following table, compiled from these 5,290 instances:
| Under 20 years | 8.8% |
| From 20 to 25 years | 25.4% |
| From 25 to 30 years | 29.4% |
| From 30 to 35 years | 21.6% |
| From 35 to 40 years | 11.5% |
| Over 40 years | 3.3% |
In these cases the maximum fertility was obtained at the age of 27.
The physiological fertility of women is much more clearly manifested when we compare the fertility of women who have been married a few years only, with the fertility of women in the later years of married life. In the earlier period, the effective fertility more nearly approaches the physiological fertility, because at this time the various influences by means of which fertility is later so greatly diminished have not yet come into operation. In this connection the following data, published by Körösi, regarding the percentage fertility of recently married women, and that of married women in general, will be found of interest:
| Recently-married women. | All married women. | |
|---|---|---|
| At ages 20 to 35 years. | 32.9% | 20.6% |
| At ages 35 to 40 years. | 32.7% | 14.7% |
| At ages 40 to 45 years. | 21.4% | 5.9% |
Inasmuch as we learn from this table that in the case of women aged 40 and upward, the newly married exhibit a fertility of four times as great as that of married women in general, in whom pregnancy has already become rare, we can infer the influence upon fertility of abstinence and of artificial measures for the prevention of conception.
On the average, the maximum fertility of woman, that is, the maximum of effective fertility, is attained at the age of 18 to 20 years. Extreme youthfulness, and also the opposite condition, too advanced an age, when marriage is entered on, impair a woman’s fertility; whereas the conditions most favourable to fertility are that, at the time of marriage, the uterus should have attained its fullest development, and the ovaries also should be completely mature; this is not usually the case at puberty, but rather at the age of 20, 21, or 22 years. In Austria-Hungary, of 100 marriages in which the wife’s age at marriage was less than 18 years, the average offspring in the course of a single year were 36 to 38 children; in the case of 100 marriages in which the wife’s age at marriage was 18 to 20 years, the average offspring in a year were 40; this being the maximum fertility, the number of offspring in a year per hundred marriages (i. e., the percentage fertility), now undergoes a regular decline as the wife’s age at marriage increases; at an age of 25, the percentage fertility is 32; at the age of 30 years, the fertility is 24%; at the age of 35, 17%; at the age of 40 years barely 10%; at the age of 45, 7%; at ages 45 to 50, 0.1%. Thus, from the last figure, we see that of a thousand women marrying at the age of 50 years, one only gives birth to a child. Men obtain their maximum fertility (i. e., procreative capacity) at the age of 25 or 26 years; at this age their fertility amounts to 35% (that is, of 100 marriages at this age, 35 children will on the average be born within a single year); at the age of 35 years, the percentage fertility of men falls to 23; at the age of 45 years, it is 9½%; at 55, 2.2%; at 65, ½% (Körösi-Blaschko).
Whereas hitherto we have considered only the monogenous fertility of married women, we must remember that the figures relating to their biogenous fertility are also of interest—that is to say, the changes which a woman’s fertility experiences in married life in respect of the peculiarities of her husband; and of these peculiarities, the easiest to make the object of statistical investigation is the husband’s age. The age of the husband exercises an important influence upon the fertility of the wife, as is proved by the following figures published by Körösi:
| Age of the Father. | Age of the Mother. | ||
|---|---|---|---|
| 25 years. | 30 years. | 35 years. | |
| 25 to 30 years | 35.6% | 25.0% | 21.2% |
| 30 to 35 years | 31.2% | 23.6% | 19.9% |
| 35 to 40 years | 27.5% | 21.8% | 19.4% |
| 40 to 45 years | 16.7% | 14.0% | |
| 45 to 50 years | 14.4% | 10.9% | |
| 50 to 55 years | 10.9% | ||
Also:
| Age of the Mother. | Age of the Father. | |||
|---|---|---|---|---|
| 25 years. | 35 years. | 45 years. | 55 years. | |
| Under 20 years | 49.1% | |||
| 20 to 25 years | 43.0% | 31.3% | 16.0% | |
| 25 to 30 years | 30.8% | 27.3% | 18.5% | |
| 30 to 35 years | 33.5% | 23.7% | 14.4% | 8.1% |
| 35 to 40 years | 18.9% | 11.8% | 6.7% | |
| 40 to 45 years | 6.6% | 6.1% | 3.0% | |
We learn from these figures that the maximum fertility is exhibited by a woman 18 years of age, when married to a man 25 years of age; less fertile is a woman 25 to 30 years of age married to a man 28 years of age; still less fertile is a woman 35 years of age married to a man 29 years of age. Neither the age of the mother alone, nor that of the father alone, is determinative of the fertility of the marriage, for the fertility of young wives married to elderly husbands is quite different from that of young wives married to young husbands. Very various age-combinations are possible, and each exhibits an average fertility peculiar to itself.
We can also regard the question from the standpoint of the difference between the ages of husband and wife respectively. In this connection, Körösi is led by his tables to the conclusion that wives between the ages of 18 and 20 years attain their maximum fertility when married to men 7 years older than themselves; women of 25 years when married to men 3 years older than themselves; women of 29 years when married to men of the same age; women of 30 years and upward attain their maximum fertility only when married to men younger than themselves. Men, on the contrary, always attain their maximum fertility when married to women younger than themselves. The age of maximum fertility differs in the two sexes, and those marriages will be most fruitful in which husband and wife are each of the age most favorable to fertility. This will be the case when the age of the wife is 18 to 20 years, and that of the husband 24 to 26 or perhaps 29 years.
In connection with the question of fertility, we have also to take into consideration the vitality of the children born, that is, what proportion of those born survive. According to Körösi’s interesting papers regarding the fertility of the inhabitants of Buda-Pesth, we learn that for every 100 marriages which have persisted for thirty years and upward, there were born, on the average, 539 children, of whom during this period 241 died, so that the percentage of survivals was 55.28. Parents who have lost one only of several children must, therefore, regard themselves as exceptionally favoured by fortune.
Social position, occupation, and religion, have, according to the last-quoted author, a notable influence on fertility. His investigations showed that the Roman Catholics and the Jews exhibited the greatest fertility; among the Catholics there were 541 children, and among the Jews 557 children, per 100 marriages. Amongst 100 Protestant families, on the other hand, only 479 children had been born. It will be seen that the theory of the comparatively enormous fertility of the Jewish race is not supported by these statistics. The Jews do, however, exhibit a greater power of rearing children, for among them the marriages of more than 30 years’ duration had 61⅔ % of the children still living; among the Protestants 57¾% survived; and among the Catholics only 52–⅗%. It thus appears that the surviving offspring per 100 marriages of 30 years’ duration were, among the Catholics 278, among the Protestants 252, and among the Jews 349.
The question whether, and to what extent, the age of the parents has an influence on the vitality of the children, is answered by Körösi’s mortality statistics in the sense that mothers below 20 years of age give birth to a larger proportion of children deficient in vital power. Where the mothers had married at the age of 16, the mortality of their offspring was, among Catholics 43%, among Jews 33%; married at 17, Catholic mortality 44%, Jewish 30%; married at 18, Catholic mortality 42%, Jewish 32%; married at 19, Catholic mortality 41%, Jewish 29%; married at 20, Catholic mortality 40%, Jewish 26%. Of the children whose fathers had married at the age of 24, 32% had died; of those whose fathers had married at 23, 37% had died; of those whose fathers had married at 20, 42% had died; and of those whose fathers had married before 20, actually 44% had died. It thus appears that the children alike of very young mothers and of very young fathers have a lessened chance of survival.
Inasmuch as the fertility of the wife is a product of two factors, her own peculiar fertility, and that of the procreating male, the question of the fertility of women cannot be accurately treated independently of this second consideration; hereby, however, is introduced a multiplicity of obscure combinations, by which the value of all the statistical data of fertility in women is seriously impaired.
These data give as the measure of fertility, the number of children per marriage actually brought up, embracing fruitful marriages, sterile marriages, and those not yet fruitful. In Berlin, in Copenhagen, and in Buda-Pesth, the average thus attained was slightly less than three births to each family, whilst the number of children actually living averaged two per family. A more accurate representation of fertility is obtained by ascertaining the number of children born, and the number of children living in relation to the duration of marriages reckoned in years, that is beginning with marriages of one year’s duration, and proceeding year by year to the highest recorded duration of marriage. In this way interesting statistics have been obtained; for example, one who has completed thirty years of married life may count on the average that five or six children will have been born to him, but may also reckon on having buried two or three at least of these. (Körösi.)
Fertility is, as many facts indicate, also dependent on nutrition. A distinct proof, says Spencer, writing on the “Coincidence between high Nutrition and Genesis,” that abundant nutriment increases the number of births, and vice versa, is found among the mammalia; compare, for instance, the litter of the dog with that of the wolf and the fox. Whilst the dog’s litter numbers 6 to 14, that of the wolf numbers 5 to 7, that of the fox 4 to 6. The wild cat gives birth to 4 or 5 kittens once a year, the domesticated cat to 5 or 6, twice or thrice annually. The most remarkable contrast, in this respect, exists between the wild and the domesticated breeds of swine. The wild sow gives birth once a year to a litter of 4, 8, or 10 pigs (the number increasing in successive litters); the domesticated sow has often as many as 17 in a single litter, whilst in two years five litters, each numbering 10 pigs, are commonly born.
Darwin also draws attention to the fact that animals under domestication, being fed more abundantly and regularly than their wild allies, procreate at shorter intervals and are markedly more fertile than the latter. He states that the wild rabbit has four litters annually, each numbering 4 to 8 young; whereas the tame rabbit reproduces its kind six to seven times annually, and gives birth to litters numbering 4 to 11. Among birds, analogous phenomena are observed. The wild duck, for instance, lays 5 to 10 eggs in the course of the year, whereas the tame duck lays from 80 to 100; the wild grey goose lays 5 to 8 eggs, the domesticated goose 13 to 18.
It must be added that this exceptional fertility is manifested in animals that are quite inactive in comparison with their wild allies; not only are they richly fed, but they get their food without working for it. Moreover, it is easy to observe that among the domesticated mammals the well-fed are more fertile than the ill-fed.
That in the human species also, fertility is influenced to a notable degree by nutritive conditions, is shown by statistical investigation. After years distinguished by an exceptionally good harvest the number of children born is considerably greater than in normal conditions; whereas after a famine the opposite is observed. Malthus’s law of population states, inter alia, that the population increases when the amount of available nutriment increases, that is, that favourable nutritive conditions cause an increase, that unfavourable nutritive conditions cause a decrease, of population. Hardships and exhausting occupations diminish the fertility of women. The remarkable fertility of the Kaffirs is referred to the fact that this people, possessing large herds of cattle, lead a life comparatively free from care; it is no less true that the Boer women, who lead a life of well-fed leisure, have very large families; whereas the Hottentot women, poor, ill-nourished, and hard working, seldom bear more than three children.
Generally speaking, it may be said that fertility of the soil, in connection with an easily gained livelihood, favours also human fertility, notwithstanding the fact that certain statistical data seem to conflict with this proposition. Sadler, for instance, concludes that an increase in the price of the necessaries of life does not per se check fertility, but, indeed, rather increases it; he considers that the apparent decline in fertility is due to the fact that the number of marriages diminishes, owing to the rise in prices. We must, however, point out, that an increase in price of the necessaries of life is often associated with a rise in wages, and is therefore not necessarily identified with deficient nutrition; when, however, such a rise in prices leads to actual want, a limitation of fertility will certainly result; this has been proved by Legoyt and Villermé with regard to failure of the crops. Famine and disease lower the number of births; a less severe deficiency of nutriment often lowers only the quality of those born. Malthus was of opinion that the population of a country at any time was related to the quantity of nutriment produced or imported therein, on the one hand, and, on the other, to the liberality with which this nutriment was distributed to the individual. In countries where corn forms the principal crop, we find a thicker population than in pasture lands; and where rice is the principal crop, the population is even more abundant than it is in corn growing countries.
Passing to the consideration of the individual nutritive elements, we find that these also influence fertility. Above all, it has been proved that alcohol notably diminishes the fertility of women. Lippich states that of 100 women in Kärnten and Krain suffering from chronic alcoholism, 28.3 were barren. In England, where the abuse of alcoholic beverages is also very frequently observed in women, the same phenomenon has been noted. Matthews Duncan held that alcohol exercised a specific deleterious influence on fertility. Moreover, in addition to the constitutional disturbances produced by the abuse of alcohol, this beverage also exercises a well-known pathogenetic influence upon the female reproductive organs; with especial frequency, chronic oöphoritis may be shown to depend on this exciting cause.
A diet consisting mainly of fish is known to increase the sexual impulse, and is said also to increase fertility. Further, a diet consisting mainly of potatoes or rice is said to favour reproduction; compare, for instance, the fertility of the Hindoos, who abstain entirely from animal food, and of the Chinese, who live chiefly on rice. Davy maintained that the women of races living chiefly on fish were handsomer and more fertile than others: and Montesquieu suggested that there was an association between the abundant population of sea-ports and also of Japan and China, and the large quantity of fish consumed in those places. On the other hand, a diet consisting chiefly of meat is said to have an unfavourable influence in this direction; in support of this view it is pointed out that races living by the chase, and living therefore almost entirely on meat, have very small families. This generalization is invalidated by the fact that Englishwomen, who eat far more meat than the women of the Latin races, are nevertheless distinguished by their great fertility.
In his “History of Civilisation in England” Buckle writes: “The population of a country, although influenced by many other conditions, unquestionably rises and falls in proportion as the supply of nutriment is abundant or the reverse.” Herbert Spencer also states that “every increment in the supply of nutriment is followed by an increment in fertility.”
It must not be forgotten that, in addition to the more or less abundant supply of nutriment, there are always other influences affecting fertility; the general mode of life, race, climatic conditions, etc., may, in various ways, co-operate with or countervail the influence of nutritive conditions. If, with the best possible supply of nutriment, there is associated a luxurious and enervating mode of life, the abuse of alcohol, severe intellectual exertion, or sexual excesses, the general result will be a diminution in fertility. And it is easy to understand why Cros, although perhaps with little justification, goes so far as to regard easy circumstances as an active cause of depopulation. “It is the poor,” he writes, “and the less wealthy departments of France, in which we find the most children.” In estimating fertility, however, we must never fail to take into consideration the more extensive employment of means for the prevention of pregnancy among the upper classes of society.
To a certain extent we can trace the influence of climate and of season upon fertility. Heat appears to favour fertility; Haycraft’s figures for the eight largest towns of Scotland show clearly how the number of conceptions rises and falls pari passu with the temperature. Lower animals also, when brought from a colder to a warmer neighbourhood, exhibit an earlier and more frequently recurring “heat.” In Europe, however, the Northern races appear more fertile than those of the south.
Of the seasons, spring is the one especially favourable to fertility. Quetelet, who proves by numerous statistical data that the maximum of conceptions occurs in May, attributes this fact to a general increase in the vital forces occurring in spring, after the cold of winter. Villermé, however, goes back to the older explanation, that the increase in the number of conceptions in May and June is due to social and economic conditions. The return of spring, especially the end of spring and the beginning of summer, a time of year in which the means of subsistence are provided in exceptional quantity, and of especially good quality, the season also of festivals and social reunion, when the two sexes are brought into more intimate contact and when the majority of marriages occur—these are the conditions associated with the season of greatest fertility. The figures of Wappaeus also confirm the influence of spring in favouring fertility. He found, however, that there were two seasons of maximal fertility. The first at the end of spring and the beginning of summer; the second in winter, especially in December. Mid-winter is for most people a period of domestic amusement and relaxation, one of exceptionally good nutrition, and of social reunion; the spring increase in fertility is a part of the awakening and increase of the reproductive forces of nature at large, which recurs every spring-time.
Every marked and sudden change in the mode of life has an unfavourable influence on fertility. Darwin reports that mares who have for some time been stall-fed with dry fodder and are then put out to grass are at first infertile after the change. Europeans going to reside in the tropics experience a notable decline in fertility as a result of the change of climate. According to Virchow, the fertility of European women who become acclimatized in the tropics declines very gradually, but in the course of a few generations is almost completely annulled.
The marriage of near kin is believed also to diminish fertility. As regards inbreeding in the lower animals, it is well known that when nearly related animals copulate, the number of the offspring is below the average. Nathusius paired a sow with its own uncle, the boar having proved productive in intercourse with other sows; the litter numbered five to six only. This sow, which belonged to the great Yorkshire race, was then paired with a small black boar, which in intercourse with sows of its own variety had procreated litters numbering six or seven; as a result of her first pairing with the black boar, the sow cast a litter numbering twenty-one whilst the second attempt produced a litter of eighteen. Similar results were obtained by Crampe, in his experiments in the inbreeding of rats.
Some authorities declare that the results of inbreeding are similar in the human species, that the marriages of near kin are less fruitful than the average. Darwin writes in this connection: “With regard to human beings, the question whether breeding in-and-in is also deleterious, will probably never receive a direct answer, for man reproduces his kind so very slowly, and cannot be made the object of experiment. The very general disinclination of nearly all races to the marriage of near kin, which has existed from the very earliest times, is of weight in relation to this question. Indeed we appear almost justified in applying to the human race the experience gained by experiment on the higher mammals.”
Darwin’s assumption regarding the effect upon fertility of the marriage of near kin in the human species, cannot, however, be accepted without qualification. In ancient times there was no uniformity of opinion on this topic. It is well known that among the Phœnicians, a son might marry his mother, and a father his daughter; and among the ancient Arabs it was the legal duty of the son to marry his widowed mother. Moses, on the contrary, forbade marriages between parents and children, between brothers and sisters, also marriage with a father’s sister, with a wife’s mother, and with an uncle’s widow.
Darwin considered that the marriage of first cousins was not unfavourable to fertility. Of 97 such marriages, 14 were sterile, whilst of 217 marriages of those not akin, 35 were sterile; the percentage in both cases being almost identical. Mantegazza, who regards kinship in marriage as unfavourable to fertility, found nevertheless that among 512 marriages of near kin, only 8 to 9% were sterile. It is widely believed that the dying out of many aristocratic families is dependent on the inbreeding so common in this class—but it must be admitted that scientific evidence in support of this belief is lacking. Incest in the human species may certainly result in fertilization. Among the Jews, marriages of near kin are very common, and often prove extremely fruitful.
Göhlert made a statistical investigation of the fertility of the reigning families of Europe, in order to throw light on this question. In the Capet dynasty, 118 marriages of near kin took place, and of these 41 were sterile; in the Wettin dynasty (Saxony), there were 28 such marriages, of which 7 were sterile, and 1 produced one child only; in the Wittelsbach dynasty (Bavaria), 29 such marriages, of which 9 were sterile, and 3 produced only one child each. Thus of 175 marriages of near kin, 57, or 32.6% remained sterile. Further, in the Habsburg-Lothringen dynasty, of 110 marriages, 25 were marriages of near kin, and of these 33% remained sterile.