II. THE SEXUAL EPOCH OF THE MENACME. (continued 6)

In isolated cases, which deserve always very serious consideration, some pathological condition in the wife may justify the prevention of pregnancy. In certain very serious general disorders, in diseases of the heart or of the lungs, in pelvic deformity, and in pathological changes of the female reproductive organs, it may be right to employ means for the prevention of pregnancy—not merely sexual abstinence, but actual measures to prevent fertilization.

The misuse of medical knowledge for the recommendation or employment of preventive measures, on the ground of humanitarian 396sentiment or social and economic considerations, must, however, be strongly resisted. Even leading gynecologists have erred in this way. Saenger writes, “Scientifically-trained accoucheurs will do much more to promote the health and well-being of women, and to protect them from sexual and other diseases, than the humanitarian efforts of the Neo-Malthusians, who transfer a purely scientific question, such as the disproportion between the number of births and the supply of nutritive material, to the sphere of medicine, regarding themselves as justified in preventing conception whenever they please, independently of considerations relating to the health of the mother * * * * * * * * A woman exhausted by frequent child-bearing, anæmic and suffering, is certainly a figure to arouse everyone’s sympathy; in so far as she is ill in consequence of injury received in childbirth, it is our duty to prevent further injury, and to relieve to the best of our ability that which has already occurred; in so far, however, as she is not suffering from any affection of the reproductive organs, but is ill owing to the lack of sufficient food, or from overwork, it is the duty of society to render assistance. Here we have to do with the social problem; the solution of which will be brought no nearer by the use of the occlusive pessary.” Fehling also maintained that a text-book of gynecology is not the proper place in which to pass judgment on so important a socio-political question. The business of the gynecologist in this matter is merely to say a word of caution against the use of various measures which are so often recommended as harmless, but are in fact dangerous to the woman who uses them.

Kleinwächter, who declares that he is far from recommending the use of preventive measures when a healthy woman wishes to save herself the trouble of child-bearing, gives as legitimate indications for their use: 1, the various forms of severe pelvic deformity; 2, certain tumours in the pelvic cavity; 3, after the removal of malignant tumours of the reproductive organs, certain general disorders, recently arrested pulmonary tuberculosis, organic heart disease, etc. Regarding these cases, Kleinwächter writes: “The wife’s life would be endangered by pregnancy, which must therefore be prevented without forbidding coitus, and avoiding the practice of coitus interruptus, which endangers her health, or of any mode of intercourse repugnant to the feelings of wife or husband.”

The most trustworthy, but unquestionably at the same time the least practicable method, for the prevention of pregnancy, is that of 397Malthus—permanent sexual continence. This recommendation, to which Tolstoi in “The Kreuzer Sonata” gives his adhesion, has recently found an advocate in a modified sense in a distinguished gynecologist, Hegar, who considers that the great fertility of the modern civilized countries of Europe entails many disadvantages—inferior physical development, increased general mortality, emigration, an unfavourable distribution of population in relation to dwelling and occupation, occasional famine—and who sees the only effective remedy in a “regulation of reproduction,” whereby the tendency to marriage and the number of births are to be diminished. The question “when is the number of children in a family too large?” is answered by Hegar as follows “A maximal limit is easy to establish. The most suitable age for child-bearing is from twenty to forty. At an earlier and a later age than this, both the mother and the offspring are liable to suffer. Between two successive births there should be an interval of about two and a half years; this would leave time for the birth of eight children. If we assume that pregnancy lasts nine months, that lactation is continued from nine to twelve months after delivery, (and if the mother does not herself nurse the child, artificial feeding or careful supervision of the wet-nurse will occupy her for a like period), to devote an additional period of six months to nine months to the complete restoration of the mother’s health cannot be regarded as excessive. For this maximum family we assume a perfect state of health on the part of the mother, a pure atmosphere, and a sufficient supply of all the necessaries of life. Illnesses, weakness, or infirmity of the mother, often indicate that the number of children should be further limited. It is easier to provide a suitable dwelling and a pure atmosphere for a small family than for a large one. The same thing is true as regards the means of subsistence.

“If the reproductive function is to be intelligently controlled,” continues Hegar, “above all it is necessary to devote attention to the age and health of the parents; but occupation, dwelling, and general environment, must also not be overlooked. Among the cultured classes of our Fatherland, people are gradually learning to form sound opinions about these matters. Among the working classes, on the other hand, especially among those engaged in factory labour, the heedless gratification of the sexual impulse is responsible for untold misery.” Hegar’s advice may be summarized as follows: If the marriage takes place after the attainment of complete maturity, in the wife at twenty and in the husband at twenty-five, 398and if procreation is discontinued in the wife at forty and in the husband at forty-five to fifty, if between successive deliveries the intervals necessary for the wife’s restoration to health are maintained, if illness and states of debility are taken into account, if sickly, hereditarily-tainted individuals are forbidden to marry—the excessive increase in population, as far as Germany is concerned, will cease to give cause for anxiety. The regulation of reproduction will, however, still be incomplete, unless we enforce a selection too rigorous for our present views. Moderation and continence must aid as far as may be necessary in preventing an undue increase in population. Hegar does not fail to point out the evil effects of an excessive limitation of the family. In a marriage when one child only is born, this child is the object of unceasing anxiety and attention, and real or imaginary dangers assume an excessive importance in the morbidly excited imagination of the parents. Hence we find a continuous excess of watchfulness and over-education in the case of the only child, to whom independent thought and action are entirely unknown. Boys become milksops, girls nervous and hysterical. In the two-children-system, again, one or both of the children may die when the age of the parents is already considerably advanced. Still in those districts of France in which this system obtains the population is well-to-do, and an exceptionally large proportion of the males are fit for military service. The use of various measures for the prevention of conception is considered by Hegar to be harmful, at any rate in the case of young women; this practice gives rise to anæmic conditions, and to nervous weakness and irritability, seldom, however, to more serious disorders, as indeed is apparent from the fact that the mortality of married women as compared with unmarried women is lower in France than in other countries.

Gräfe, with reference to the view that if for any reason conception must be prevented, this should be done by abstinence from sexual intercourse, remarks: “Doubtless an ideal demand, but one which even those with exceptional strength of will are unlikely to satisfy. And the worst of it is, that even a single indiscretion will often result in impregnation. Moreover, it is distinctly contrary to natural conditions, that a healthy married couple united by an intimate affection should live together abstaining completely from sexual intercourse. The question has already been much discussed, both in speech and writing, and this will continue in the future, without altering the fact that the physician will be asked, and will be 399compelled to give, advice regarding the use of means of the prevention of pregnancy.”

Ribbing writes, “Although the sexual impulse is the product of a powerful natural developmental force, still the temporary, and sometimes even the permanent, control of this impulse is a moral civilizing force of enormous importance.” This writer is opposed to the use of artificial preventive measures; he considers them untrustworthy and dangerous to health. Untrustworthy, for the reason that nature has endowed living organisms with a strong impulse toward conjugation and has equipped with very powerful forces the processes by which fertilization is effected. Every physician is familiar with cases in which preventive measures have proved ineffective. This fact is proved also by the statistics of prostitution. Although prostitutes are fully instructed in the use of preventive measures, which they almost universally employ, nevertheless every year a smaller or larger number of prostitutes become pregnant. These measures are dangerous to health, partly because of their interference with natural functions, because many of them are clumsy and ill adapted; and partly, again, because owing to their use the woman fails to enjoy the natural periods of repose which are entailed by pregnancy, parturition, and lactation. Noteworthy also are the psychical considerations adduced by Ribbing against the use of preventive measures. The majority of well-bred women feel deeply wounded if they believe themselves to be regarded merely as a means of enjoyment, not as individuals, as persons with inalienable rights. For the man also there is danger, for it is easy for him to acquire a dislike to the wife who, even though on his own initiative, occupies herself with the technique of the sexual life in a manner which he feels instinctively to be opposed to the chastity and puremindedness demanded by every man from his wife. Ribbing therefore advises a certain measure of sexual abstinence in married life.

Max Nordau also insists on the moral disadvantages of the wide diffusion of the use of preventive measures. “If a race or nation has reached this point in its downward career, the individuals of which it is composed lose the capacity of loving in a healthy and natural manner. The sense of the family disappears; the men will not marry, because they find it inconvenient to burden themselves with the responsibility for another human life, and to care for any other creature than themselves; the women dread the pains and inconveniences of motherhood, and if they marry, they endeavour, 400by the employment of the most immoral means, to ensure barrenness. The reproductive instinct, of which reproduction has ceased to be the aim, is in some annulled, whilst in others it degenerates into the most peculiar and irrational perversities. The act of sexual union, the most sublime function of the organism, is degraded into a profligate act of lust; it is no longer undertaken in the interest of the perpetuation of the species, but exclusively for the pleasure of the individual, and without any relation to the needs of the community.”

Alfred Russel Wallace has advocated sexual continence as a preventive measure during the period of maximum vitality and strength; he advises that the age of marriage of women should be considerably advanced, in order to diminish their fertility. If woman’s average age at marriage were 29, instead of 20 years, the fertility of marriages would be reduced in the ratio of 8 : 5.

The desired goal of artificial sterility will not, however, be reached through the advocacy of moderation and continence. The numerous additional measures employed for this purpose may be classified as physiological and artificial; the latter class may be further subdivided into mechanical and operative.

By physiological means for the prevention of conception, we understand measures which aim at producing sterility by reducing the number of acts of intercourse and by restricting these acts to certain defined periods of time. The physiological preventive measures, apart from the higher ethical value they possess in comparison with artificial measures, have the advantage that they may be regarded as harmless to the general health of the woman and to the integrity of her reproductive organs in particular; they have, however, this very serious disadvantage, that the results of their use are very uncertain, so that they offer no more than a probability, and often a very moderate probability that conception will be prevented.

As a physiological measure for the attainment of facultative sterility “without breaking any moral law,” Capellmann advised abstinence from coitus during a period of fourteen days after menstruation and three to four days before the commencement of the flow. Without laying too much stress on the fact that by following this recommendation the period during which the intercourse is permissible would be extremely restricted, it is necessary to point out that, whilst in this way the occurrence of conception may be rendered less probable, its prevention is by no means guaranteed, 401for it is an established fact that a woman may be impregnated by intercourse on any single day of the intermenstrual interval. Capellmann’s advice, embodying, as he expresses it, the “only morally permissible” means for the prevention of conception, was not original, for the same recommendation was given at an earlier date by Raciborski, who, however, regarded the measure as very uncertain. Capellmann is of opinion that it is sufficiently trustworthy for practical purposes.

Bebel, who is a declared opponent of Malthusianism, none the less lays down positive rules for the diminution of procreative capacity and of fertility by regulation of the diet. He refers to the example of the bees, which, by a change of nutriment, can produce a new queen-bee at will. “Thus the bees,” he says, “are in advance of human beings in their knowledge of sexual development. Presumably they have not been compelled, for a couple of thousand years, to listen to sermons informing them that to occupy themselves about sexual matters is ‘improper’ and ‘immoral.’ There is no doubt whatever that the mode of nutrition has an influence on the composition of the male semen, and also on the susceptibility to fertilization of the female ovum; hence the increase in population must to a very important extent depend on the mode of nutrition. If this could be definitely established, we should have, in the supply of nutriment, a means of regulating the population. As an example of the effect, in this connection, of the mode of nutrition in the human species, it is reported that in consequence of the fatty and nutritious diet of the old Bavarian peasants, who lived chiefly on very rich puddings, the marriages of the well-to-do peasants were frequently childless. However, it must not be forgotten that pre-conjugal intercourse, which was customary in that part of the world, and was somewhat promiscuous in character, may have contributed to cause this sterility.” Finally, Bebel points out that the woman of the future “will be unwilling to bear a large number of children. She will wish to enjoy a measure of personal freedom and independence, and will not consent to pass half or three-quarters of the best years of her life either pregnant, or with a child at her breast. From this it will result that the population will be regulated, without unwholesome sexual abstinence, and without the employment of unpleasant preventive measures.” However, Bebel gives us no details as to the precise manner in which this regulation is to be effected.

Tolstoi, in his widely celebrated book “The Kreuzer Sonata,” 402condemns absolutely the gratification of the sexual impulse. He demands the recognition of the fact that “sexual congress, in which a man either avoids the natural consequences—the birth of children,—or else throws the whole burden of these consequences on the woman, is opposed to the simplest demands of morality, is in fact utterly base.” To render possible the sexual abstinence he regards as morally necessary, men must not only endeavour to live in a natural way, but they must consume no alcohol, eat with great moderation, abstain from meat, and not be afraid of hard work. Tolstoi even demands that men and women shall be so brought up “that both before and after marriage they may regard love, and the sensual passion associated therewith, not as they do at present, as a sublime and poetical state, but as a bestial condition degrading to humanity.” Tolstoi is, however, utterly opposed to the use of preventive measures: “first, because they liberate men from the cares and sorrows entailed by having children, which must be regarded as the penance to be paid for sensual love; and, secondly, because their use is closely allied to the crime most repugnant to the human conscience, the crime of murder.” Chastity is no less a duty after marriage than before; after marriage man and wife must “continue to pray to be delivered from temptation, and must endeavour to replace sensual love by the pure relationship of brother and sister.”

Eulenburg regards the modern diffusion and the continuous increase in the use of preventive measures as signs of decadence; Löwenfeld, on the other hand, regarding the social conditions of the present day as the principal source of the use of preventive measures, sees therein no moral decay, but on the contrary rather a rise in the moral standard of life.

Another physiological means of prevention is to be found in avoiding cohabitation in that season or month in which, judging by the woman’s previous deliveries, she would appear to have been peculiarly susceptible to impregnation. Cohnstein maintained that in woman, as in the lower animals, the capacity for conception was associated with a particular season of the year, that there was, in fact, an individual time of predilection for impregnation. The assumption that there is such a time of predilection is, however, traversed by the fact, familiar to all who have recorded the birthdays of children in large families, that these occur in the most diverse months of the year. It has, indeed, been statistically proved that certain months and seasons are especially favourable to conception, that a maximum of conceptions occurs in the spring, and 403a second much smaller maximum in the winter; but these variations in the number of conceptions depend mainly on social factors, as, for instance, upon the customary season for marriage, opportunity for intercourse between the sexes, common labours in the house or in the open, etc. This alleged time of predilection for conception cannot, therefore, seriously be considered in the discussion of measures for the prevention of pregnancy.

As a physiological means for preventing conception, passivity of the woman during sexual intercourse has also been recommended. It is well known that an active participation on the part of the woman in the sexual act, by increasing her voluptuous sensations, gives rise to certain reflex actions, viz., descent of the uterus, rounding of the os uteri, induration of the portio vaginalis, and, finally, ejaculation of the secretion of the cervical glands and of the glands of Bartholin; these changes accelerate the entrance of the semen into the cavity of the uterus, and increase the motility of the spermatozoa. Upon this fact is based the assumption, that, in consequence of deficient sexual excitement during intercourse, either spontaneous, or when the woman intentionally remains “cold,” the reflex actions by which the upward passage of the spermatozoa is favoured, fail to occur; there is a good deal of evidence in favour of the truth of this view. Riedel reports regarding the women of the Island of Buru, that they often have sexual intercourse with strange men, “but during sexual congress in such cases they maintain a passive and indifferent state, for the purpose of avoiding impregnation.” Von Krafft-Ebing points out that prostitutes, when having sexual intercourse with men to whom they are attached, experience voluptuous excitement, whilst in intercourse with men to whom they are indifferent they remain entirely passive. From this it would appear that these uterine reflexes are under the dominion of the conscious will; but sufficient dependence cannot be placed on this fact in all circumstances for it to be possible to employ such voluntary control as a trustworthy means of prevention. Allied to this is previously-mentioned Chinese practice of Kong-fou, a kind of hypnosis, in which during sexual intercourse the thoughts are concentrated on some other matter, and thereby conception is supposed to be prevented.

Artificial protraction of the period of lactation is an old and well-known method, practised by many savage peoples, for the prevention of fertilization. As a general rule, as long as lactation continues, amenorrhœa persists, and sexual intercourse remains unfruitful. But this rule also is not universally valid.

404Artificial means for the attainment of facultative sterility are those by which the attempt is made to prevent pregnancy by some mechanical hindrance to the contact of the semen with the ovum, since without this contact conception cannot possibly occur.

The oldest of these means is that described in the book of Genesis (ch. xxxviii, verses 9, 10), congressus interruptus, where, however, the practice was punished by death, “And Onan knew that the seed should not be his; and it came to pass, when he went in unto his brother’s wife, that he spilled it on the ground, lest that he should give seed to his brother. And the thing which he did displeased the Lord, wherefore he slew him.” This mode of preventing pregnancy, in which the membrum virile is completely withdrawn from the vagina before the ejaculation of the semen takes place, is at the present time a very widely diffused practice; and, when properly carried out, it is thoroughly efficacious in the production of sterility. Thompson relates that this practice is employed by the Massai youths, who are allowed free intercourse with the girls, but if a girl becomes pregnant she is put to death.

The prolonged practice of coitus interruptus leads in my experience—in addition to the injury to the nervous system as a whole in consequence of the intense hyperæmia of the uterus and the uterine annexa, unrelieved by the occurrence of the orgasm—to a condition of stasis in the female reproductive organs; and this ultimately passes on into chronic metritis (with relaxation of the uterus, retroflexion or anteflexion, catarrhal disease of the mucous membrane, erosions, and follicular ulceration of the portio vaginalis), oöphoritis and perimetritis. As a result of certain remarkable observations, I must even regard it as not improbable, although actual proof is still lacking, that the recent striking increase in the frequency of neoplasmata of the female reproductive organs is causally dependent on the ever-increasing employment in all circles of society of means for the prevention of pregnancy.

The evil effects of coitus interruptus for a woman are dependent on the fact that the woman fails to obtain complete sexual gratification, and that this has an important influence upon her entire organism. Owing to the failure of ejaculation to occur, the blood, which during the stage of sexual excitement has accumulated in the erectile structures and cavernous spaces of the genital passage, does not, as in normal conditions, flow rapidly away; but the congestion persists for an indefinite period, and is said by von Krafft-Ebing to give rise to functional disorders, and also to serious tissue 405changes. The functional disorders take the form of hyperæmia of the pelvic organs, and probably also of the lumbar portion of the spinal cord (dull pain in the sacral region, a sensation of pain and dragging in the pelvis and in the lower extremities, lassitude); these symptoms often continue for several hours after intercourse. If this ungratifying coitus is frequently repeated, in a voluptuous woman, disorders of the reproductive organs ensue; and even more frequently, nervous disorders, in the form of neurasthenia sexualis. This author considers that, more especially in women, coitus interruptus, and unphysiological modes of sexual intercourse in general, are extremely potent causes of sexual neurasthenia—as potent as masturbation.

Beard, in his work on sexual neurasthenia, maintains that the sudden interruption of coitus (and also the use of condoms and similar appliances) is not only far more deleterious than unduly frequent normal intercourse; but he points out that it is necessary also to take into account the fact that (inasmuch as, owing to the unnatural mode of sexual intercourse, the possibility of fertilization is almost completely prevented) sexual intercourse is apt, in such cases, to be indulged in far more frequently, and often to gross excess. More particularly in such circumstances are evil effects on the nervous system likely to ensue, since we have a combination of excessively prolonged and frequent sexual intercourse, and of interference with complete sexual gratification.

Mantegazza believes that organic diseases of the spinal cord may actually result from congressus interruptus.

Hirt considers that even when marital intercourse is carefully regulated in respect of frequency, congressus interruptus may lead to neurasthenic manifestations.

Von Hösslin believes it to be indisputable that preventive methods of sexual intercourse may cause nervous troubles, and more particularly neurasthenic disorders, manifesting themselves chiefly in the sphere of the reproductive organs.

Eulenburg also declares that coitus interruptus is already a frequent cause of sexual neurasthenia in women, and that its evil influence in this respect is becoming more and more frequently manifest. He publishes two typical cases, in which, from this cause, in the one case, functional neuropathy, and in the other, local disorder of the reproductive organs, ensued.

Freud describes an “anxiety-neurosis,” which is due to incomplete gratification of the woman during sexual intercourse. Coitus 406interruptus is almost invariably harmful to the man; to the woman it is harmful if the man thinks only of himself, and interrupts the coitus as soon as ejaculation is imminent, without concerning himself about the woman’s state of sexual excitement. If, on the other hand, the man waits until the woman’s sexual gratification is complete, the significance of such an interrupted coitus as far as the woman is concerned is that of normal intercourse.

Isolated authorities, as for instance Stille and Thompson, have contested the alleged evil consequences of preventive methods of sexual intercourse. “It is habitual excess,” says Fürbringer, “which does the mischief, not the unnatural character of the isolated act.” Löwenfeld, who considers the opposition of medical men to “Malthusianism” not wholly justified, and believes that the dangers to health “which occur in isolated cases” are not very serious, maintains none the less that the medical man must advise his patients not to practise coitus interruptus. The mode in which conception is prevented is not, he thinks, a matter of indifference to the woman. The use of occlusive pessaries and similar appliances does not in any way interfere with the normal development of sexual gratification and cannot, therefore, have any direct influence in the production of nervous disturbances. A forgotten occlusive pessary, however, has in many cases caused local disorder in the vagina. When the man is fully potent the use of condoms can do no harm to the woman, since the only effect of the condom (in a very excitable woman) is to render the development of the orgasm a little more difficult, but not to prevent it. Congressus interruptus itself is, according to Löwenfeld, harmful to the woman only when, owing to deficient potency in the male or to deficient excitability in the female, the interruption takes place before the occurrence of the orgasm.

Valenta declared that coitus interruptus was one of the chief causes of chronic metritis. Elischer saw perimetritis result from this practice; Gräfe enumerates, as consequences of frequently repeated coitus interruptus, chronic hyperæmia of the uterus and oöphoritis; Goodell observed elongation of the cervix uteri; Mensinga, infarction of the uterus, œdema of the portio vaginalis, ulceration of the cervix, hysterical paroxysms, convulsions, cephalalgias, cardialgias, etc. Lier reports a case in which, after three years’ continued practice of coitus interruptus, the menopause set in, with atrophy of the uterus; Ascher, in a similar case, saw chronic metritis ensue. According to Kleinwächter, coitus interruptus is 407harmful to the woman to an extent by no means trifling, whereas the man, in whom ejaculation occurs, suffers comparatively little. Fehling believes that when coitus interruptus is practised only a small proportion of women experience sexual excitement. Neugebauer states that among the very numerous cases of uterine carcinoma he has treated, the majority of the patients admitted having practised coitus interruptus. Pigeolot makes a similar statement.

It must, however, be admitted that a certain number of medical men absolutely deny the dangers of coitus interruptus, whilst others consider them altogether trifling. Just as the trend of modern opinion is to believe that in normal men and women the dangers of masturbation are far less serious than was formerly maintained, so also many are now found to maintain that coitus interruptus is harmful only to those with hereditary neuropathic predisposition. Still more unwilling are many to admit that other preventive methods do women any harm. Thus Wille maintains that the continued fear of pregnancy will in most instances do more injury to the feminine nervous system than all the preventive measures in the world. To the nervously weak woman a trustworthy preventive of pregnancy is therefore often necessary and most helpful.

An artificial method for the prevention of the ejaculation of semen was communicated to me by a celebrated anatomist. It is practised in Transylvania and in France. During intercourse the woman, just before the male ejaculation begins, presses forcibly with her finger on the base of the erect penis just in front of the prostate; the urethra is occluded by this digital compression, the semen regurgitates into the bladder and is subsequently evacuated with the urine.

This practice may be compared with the mechanical expulsion of the semen from the female genital passage immediately after coitus. Tairi reports that women of the poorer classes in Italy sit upright in bed immediately after intercourse, and by coughing, in conjunction with pressure on the abdomen, effect the expulsion of the semen. Morton informs us that the native women of Northern Australia, when they have had intercourse with a white man and wish to avoid impregnation, likewise deliberately effect the outflow of the semen post actum. The woman squats upright, with the legs widely separated, and by a sinuous movement of the perineum and a simultaneous powerful bearing-down pressure she expels the semen on to the ground.

Another way in which the attempt is made to avoid impregnation 408is by the use of vaginal injections; a fluid lethal to the spermatozoa being used for this purpose immediately after coitus. Douches of cold water, ½ to 1% solution of copper sulphate, 1% solution of alum, ¼% solution of sulphate of quinine, are the fluids most commonly employed; but all these are quite untrustworthy, for it is impossible to be sure that all the spermatozoa will be acted on and destroyed. Allbutt, who as medical secretary of the Malthusian League in London has unquestionably had a very wide experience, agrees with Haussmann in denying that the widely advocated cold water douche can be relied on for the prevention of pregnancy. The sudden driving of the blood out of the vessels of the genital passage at the very moment when they are intensely congested, which must inevitably result from a cold douche, is, moreover, likely to give rise to metritis, perimetritis and oöphoritis.

More trustworthy are the various apparatus, the aim of which is to prevent the contact of the semen with the ova by the interposition of an artificial wall. Although even as regards these we must bear in mind the observation of Lott, who found that spermatozoa were capable of passing through the intact membrane in favourable regions in as short a time as ten minutes. The commonest of all these apparatus is the article known as a condom, which envelops the penis with a membrane, variously consisting of isinglass, the lamb’s cæcum, or caoutchouc. Condoms, if made of suitable material, and if carefully used, are the most trustworthy of all preventives. Moreover, the injury caused by their use to the woman’s health is trifling, for they do no more than diminish to a degree the intensity of the stimulus, thus necessitating a somewhat longer duration of its action in order to effect the most intense orgasm, and thus to induce the natural physiological termination of the nervous excitement. In fact, though somewhat delayed, the normal reaction takes place in the reproductive organs. The evil effect of the use of the condom bears no comparison with that of coitus interruptus. There is, however, some justification for Ricord’s well-known epigram, that the condom is “a spider’s web for the prevention of danger, and a cuirass for the prevention of voluptuous pleasure.”

When the gynecologist, from well-considered reasons based on some pathological condition affecting his patient, feels justified in recommending the prevention of pregnancy, it is my opinion that the most trustworthy and least harmful measure at present available, and one preferable to all other mechanical apparatus, is a carefully selected and well-made condom.

409The condom was already in use in Italy in the middle of the sixteenth century, in the form of a linen investment adapted to the shape of the penis; subsequently, according to Grünfeld, condoms were made from the cæcum of the lamb; while later still, isinglass was employed for this purpose. According to Hans Ferdy, the cæcal condom is made from the connective-tissue layer of the cæcum of the sheep or of the calf (a very young animal); to a less extent, also, the cæca of the goat, the stag, and the roe-deer, are employed for this purpose. The different varieties of cæcal condom are distinguished chiefly by variations in the thickness and the softness of the membrane. Ferdy states that the four best kinds are made from the cæcum of the sheep; these have a thickness: I. 0.008 to 0.01 mm. (0.00032 to 0.0004 in.); II. 0.012 to 0.015 mm. (0.00048 to 0.0006 in.); III. 0.017 to 0.023 mm. (0.00068 to 0.00092 in.); IV. 0.025 to 0.03 mm. (0.001 to 0.0012 in.) Next in quality come four varieties obtained from the calf, varying in thickness from 0.015 to 0.04 mm. (0.006 to 0.016 in.) Finally we have three varieties obtained from the three other animals already mentioned. Thus there are in all eleven varieties of cæcal condom, and in so far as during the process of manufacture the membrane has remained free from any injury, they are sold as “undamaged.” But if in the process of preparation a hole has been made in the membrane, this aperture is closed by sticking on a small patch of membrane. Such patched condoms are naturally quite useless, since the patch is readily loosened by the moisture to which it is exposed, and falls off, when the protective and preventive functions are entirely destroyed; nevertheless, such defective condoms are often sold. Rubber condoms, continues Ferdy, are prepared from a caoutchouc membrane 0.03 to 0.1 mm. (0.0012 to 0.04 in.) in thickness; but these, he says, are not hygienic, for “such a rubber membrane, which both in the man and in the woman completely covers the erogenic zones normally stimulated in coitus, deadens the necessary stimulation, so that the sensations during coitus are seriously dulled by the interposition of this foreign body; by nervously predisposed individuals, this kind of condom cannot be used regularly for a long period, without rendering probable the onset of serious functional disturbances of the genital apparatus.” This opinion appears to me to be unfounded. We must also mention the “glans-condom,” made of rubber membrane, which serves to cover the glans penis only during coitus, and to retain the seminal secretion; its grave defect, however, consists in 410this, that in the act of withdrawing the penis, the condom is very likely to be peeled off, when the semen will, after all, pass into the vagina.

Passing now to the consideration of apparatus which are inserted into the woman’s genital canal, in order to prevent impregnation, we may first mention sponges, which have long been in use; after thorough cleaning, these may be rendered aseptic by immersion in carbolic acid or lysol solution. These sponges should be very soft; they are cut into balls of 3 to 7 cm. (1.2 to 2.8 in.) in diameter; before coitus they are introduced into the vagina and after coitus they are withdrawn by means of the tape which should always be attached to them. This method is, however, quite untrustworthy, for the sponge offers no impermeable wall to the passage of the spermatozoa, and on its withdrawal, some of the semen may very likely be left in the vagina. The same objection must be made to the similarly constructed anti-conceptional cotton-wool plugs; sometimes these are moistened with a fluid intended to destroy the spermatozoa. Recently Gunzburg has recommended the introduction into the vagina of a cotton-wool plug moistened with a three per cent. solution of carbolic acid in glycerine; he considers this method safe, because the spermatozoa are immediately destroyed on contact with the weakest carbolic acid solutions.

To destroy the vitality of the spermatozoa, vaginal suppositories made of cocoa-butter medicated with hydrochlorate of quinine have also been employed; these, the so-called “security-pessaries” or “security-ovals,” are inserted into the vagina half an hour before coitus; the cocoa-butter is melted by the body heat, and the vaginal mucous membrane and the os uteri are covered with the medicated fatty material, by which the spermatozoa are (or should be) destroyed. This method is one easy to employ, but it is extremely uncertain.

Even more uncertain are the insufflators charged with various powders (boric acid, citric acid, thymol, etc.); the tube of the insufflator having been passed into the vagina, the powder is blown over the vaginal mucous membrane and the portio vaginalis. This procedure may sometimes be followed by symptoms of intoxication; and in any case, owing to the desiccative effect which the powder has upon the vaginal mucous membrane, it exercises a disturbing influence on coitus.

Kleinwächter, in cases in which pregnancy must be prevented in the interest of a woman’s health or her life, has recommended the 411introduction into the vagina of globules of which the active constituent is boric acid.

A rationally constructed apparatus, and one which in general appears to fulfil its purpose very well, is the pessarium occlusivum constructed by Mensinga, and now manufactured in various modifications. The occlusive pessary is a hollowed hemisphere of rubber membrane, around the margin of which passes a steel ring. The size of the pessary must be adapted to the individual case. It is introduced into the vagina in such a way that the outer surface of the hemisphere occupies the vaginal fornix, while the steel ring touches the vaginal wall all round; by this means, the vaginal fornices and the os uteri are completely shut off from the lower part of the vagina. The disadvantage of this instrument is, that either the woman must wear it continuously, which involves numerous inconveniences, or else it must be introduced by the skilled hand immediately before coitus—and not every woman becomes competent to adjust it herself, even after careful explanation, since the pessary must be accurately placed with the anterior margin of the ring immediately behind the pubic symphysis, and the posterior margin of the ring behind the os uteri. Moreover, the instrument may easily be displaced by violent movements, coughing, sneezing, etc. In any case, the pessary must be carefully selected to correspond within the configuration of the vagina, as otherwise it may exercise a deleterious pressure upon the vaginal walls, and may give rise to other bad consequences, such as are apt to attend the wearing of any pessary for a prolonged period—excoriations, erosions, fluor albus, etc. In the majority of cases it will be found that the woman herself is not competent to introduce the occlusive pessary. The skilled hand is needed for the proper adjustment of the surrounding ring.

Gall’s balloon-occlusive-pessary consists of a soft elastic rubber disc, surrounded by a thin-walled rubber ring, the interior of which is connected by means of a fine tube with an inflating rubber ball. The woman can herself insert the instrument and inflate the ring; it occludes the vaginal passage without exercising any deleterious pressure.

Other pessaries consist of hollow rubber balls containing some fluid lethal to the spermatozoa, which can be discharged into the vagina on opening a valve by pulling a string. These, however, are as insecure as the above-mentioned vaginal discs and the insufflators. The duplex-occlusive-pessary has the form of a truncated cone 412with double walls; in its base are a number of rounded apertures, and a single elongated aperture; through this latter a boric acid tablet is introduced into the cavity of the cone. By means of the cone the passage to the uterus is mechanically occluded; the semen passes through the apertures in the base into the interior of the instrument, and as the boric acid tablet is dissolved by the moisture to which it is now exposed, the vitality of the spermatozoa is destroyed. The management of this apparatus is, however, not easily effected by the woman herself. The “Matrisalus-Pessary” differs but little from other occlusive pessaries. The latest instrument for the prevention of impregnation is known as the “Venus-Apparatus;” it consists of a syringe with two balls, a large and a small one, at either end of a rubber tube; by pressure on the larger ball, and subsequent relaxation of pressure, the smaller ball is filled with a fluid for the destruction of the spermatozoa (prepared by the solution of one of the “Venus-powders” sold with the instrument); when filled, this smaller ball is introduced into the vagina and remains connected by means of the tube with the larger ball, which lies between the woman’s thighs. At the moment of the male ejaculation the woman presses on this ball, and by this means the fluid filling the smaller ball is expressed into her vagina.

All these mechanical occlusive pessaries are open to the objection that they are apt to give rise to irritative conditions of the genital organs, causing offensive discharges, pruritus, etc. (Recently in order to diminish this drawback, the pessary has been constructed of vulcanized cambric, instead of rubber, and appears then to have a less irritating effect.) Still worse is the injury to the uterus and to the cervical mucous membrane caused by certain intra-uterine instruments which have been recommended for the prevention of conception. The latest of these is an “obturator,” consisting of a silver or silver-gilt tube, which is passed through the os uteri into the interior of the uterus, and left in situ. It is claimed for it that “it allows the menstrual discharge to flow freely away, but renders the entrance of the spermatozoa extremely difficult.” Biermer reports five cases in which serious injury to health followed the use of one of these obturators. In one of these cases in which there were very severe pains and a discharge from the uterus, Biermer removed from the interior of the uterus a broken wing of the obturator; the patient died, however, and the autopsy disclosed perforation of the uterus. In another of the cases the apparatus was also broken.

413Less dangerous is the recently invented tampon-speculum. This is passed into the vagina by the woman herself, in order that through it she may, by means of a special introducer, insert a tablet of boric acid, hydrochlorate of quinine, citric acid, or some other substance lethal to the spermatozoa. Without some such instrument, the introduction of these “ovals” to the proper place is often found difficult by women.

A very remarkable means of bringing about artificial sterility, one resembling the operative procedures sometimes adopted in western countries, is employed in various parts of the world, and notably in the East Indies and in the Sunda Islands, namely, the induction of an artificial malposition of the uterus, more especially of anteversion. Thus, van der Burg writes from the Dutch Indies: “In the girls the sexual impulse develops very early, and is gratified without fear of consequences, when the services of certain skilled elderly women have been requisitioned.” These women appear, in fact, to understand, by means of pressure, rubbing, and kneading, through the abdominal walls (not by the vaginal route), how to induce anteversion or retroversion of the uterus, to such an extent as to prevent the occurrence of conception. It is said that the only inconvenient consequences of this procedure are trifling pains in the lumbo-sacral and inguinal regions, and some trouble in passing water during the first few days after the manipulations have been effected. Later, when a girl who has been treated in this way wishes to marry and become a mother, by a reversal of the manipulations the uterus is restored to its natural position. It is said that these skilled women have been called in by European women in the Dutch Indies, who did not wish to have many children; but it appears that in a woman who has once given birth to a child, the result of the manipulations is less to be depended upon, than in the case of a virgin.

A means of ensuring artificial sterility, which in all civilized states is punishable as a criminal offence, and which is nevertheless very frequently practised, is the artificial induction of abortion. Especially in North America it would appear that there exist regular professional abortionists. In this connection, Thomas, the well-known American gynecologist, writes as follows: “Statistics showing the frequency of criminal abortion are not, and probably never will be, available, for this crime cannot be adequately controlled by human society, and commonly eludes legal punishment. It seems a hard saying, but it is a true one, to assert, that the law pursues 414unremittingly him who has killed his fellow-man, while it leaves immune him who has killed the embryo in the mother’s womb. On my table there lies at this moment one of the most widely circulated, most respected, and most carefully edited daily newspapers of New York—a paper which finds its way into the best circles of society, and also into the hands of girls and women throughout the country. In its columns I find fifteen advertisements which emanate beyond all question from professional abortionists—from men and women who gain their livelihood by child-murder.”

O. Reyher remarks also that in American newspapers advertisements such as the following are of every-day occurrence: “Pills for the regulation of the periods. Ladies expecting to be confined are warned not to use them on any account, for if they do so abortion will infallibly ensue.”

Emmet, in his “Textbook of Gynecology” also complains of the terrible frequency of criminal abortion, so that “every day we see more unhappiness and misery result from the misuse of conjugal relationships than we see in an entire month as a result of births which take place in a natural manner.”

Pomeroy also says that “The prevention of conception and the destruction of the unborn life are pre-eminently American sins;” and he adds that if no bounds are set to their spread, “they must, sooner or later, lead to universal misfortune. In the course of our practices we come into contact with women who would hesitate to kill a fly, but who think nothing of having destroyed half a dozen or more of their own unborn children.”

The American Medical Congress offered a prize for a brief and readable essay, suitable for diffusion among women, showing the criminality and the physical harmfulness of artificial abortion. The prize was awarded to Storer’s essay, entitled “Why Not?”

Among the ancient Greeks, the fear of over-population led to the practice of homosexual intercourse. The states of ancient Greece were in most cases of a very small area, so that a very moderate increase in population would render the means of subsistence insufficient. Hence intercourse with women was avoided, and the sexual impulse was gratified in unnatural ways. Inspired by this fear of over-population, Aristotle urged upon men that they avoid women, and should indulge in the love of men and boys, and at an earlier date, Socrates had celebrated the love of boys as a mark of higher culture. The most notable men of classical Greece practised homosexual intercourse; authors and poets celebrated the love of boys. Stimulated by their example, Sappho of Lesbos became 415the inspired poetess of the love of women for members of their own sex (Lesbian love).

Among the Romans it was rather satiety in consequence of sexual excesses which led in that country to the diffusion of the Greek love of boys; the consequent childlessness diminished to such an extent the numbers of the Roman burghers and patricians, that Augustus, in the year 16 B. C., enacted the Julian law, by which the procreation of children was rewarded, whilst celibacy became a punishable offence.

At the present day the fear of an excessively large number of children, in relation to the property possessed by the parents and in regard to nutritive possibilities, has led among whole classes, and even among entire nations, to the adoption of preventive measures in sexual intercourse; these measures have, in fact, been developed into a system, which finds adherents among all strata of the population, but more especially, as it is easy to understand, among certain well-to-do sections of the community. In France this system has been adopted to such an extent as to amount to a national calamity.

In few countries of the civilized world, remarks Bebel, are marriages so frequent, relatively to the population, as they are in France, whilst in no country is the average number of children per marriage so small, or the increase of population so slow. The French bourgeoisie long ago adopted this system, and the peasantry and the artizan classes are following their example. In many parts of Germany the same causes have led to the same results. In France, in addition to the prevention of pregnancy and the practice of artificial abortion, infanticide and the exposure of children are also actually employed to keep down the population.

Operative measures for the production of artificial sterility have been practised from very ancient times, and by civilized and savage peoples alike. According to Strabo, the ancient Egyptians and Lydians were acquainted with the art of removing the ovaries from girls and women. The kings of Lydia, Andromytes and Gyges, had the women of their harems castrated, ut iis semper ætate et forma florentibus uteretur. Von Micklucho-Mackay reports that in some parts of Australia the indigens remove the ovaries of certain girls, in order to provide their young men with hetairæ who cannot possibly become pregnant. M. Gillirray saw at Cape York a native deaf and dumb woman whose ovaries had been removed, to prevent her procreating deaf and dumb infants.

416We cannot refrain from reference to the astounding proposal of C. A. Weinhold, contained in his work upon the over-population of Central Europe and its consequences to the countries concerned and to civilization in general. He advises, “as a general and urgently required measure, the widespread practice of a sort of infibulation, which is to be undertaken at the age of fourteen and preserved until marriage, and is to be performed in the case of all those individuals who can be proved not to possess sufficient property for the upbringing of an infant, if they should become pregnant as a result of extra-conjugal intercourse. And in those who never attained a financial position in which they might be able to bring up a family, the infibulated condition should be allowed to persist throughout life!”

This proposal is, in fact, no novelty, inasmuch as the bringing about of an artificial adhesion of the labia with a view to the prevention of conception—the operation of infibulation—is practised by many savage peoples. According to the detailed account given by Ploss-Bartels, this operation, in which the inner surfaces of the labia majora are freshened, stitched together, and allowed to adhere, is practised by the Bedschas, the Gallas, the Somalis, the inhabitants of Harrar, at Massaua, etc. The purpose of this practice is to preserve the chastity of the girls until marriage, when the reverse operative procedure is undertaken. If the husband goes away on a journey, in many cases the operation of infibulation is once more performed upon his wives. Slave-dealers also make use of this operation so as to prevent their slaves from becoming pregnant. It is reported, however, that the operation does not invariably produce the desired effect. Hartmann informs us that in Nubia, in Senaar, and in part of Kordofan, the præputium clitoridis or the entire clitoris is cut away, and the margins of the nymphæ are then freshened and stitched together, so that the only aperture left is one sufficiently large for the outflow of the urine.

Brehm states that the operation is performed by old women, who make the necessary incisions with razors; shortly before marriage, the bridegroom sends the girl’s relatives a model of his penis, carved in wood, according to the size of which an aperture is made between the adherent nymphæ; when the woman becomes pregnant, the incision is still further enlarged. In the kingdom of Darfur, the labia majora as well as the nymphæ are freshened and stitched together. In the Berber country, Werne became acquainted with a young widow whose husband had had her submitted to the operation 417of infibulation no less than seven times. Another somewhat less brutal method of performing infibulation is described by Ploss, as being practised by many Eastern races; a ring is fastened through the labia in such a way as to guard the introitus vaginæ In Europe, during the Middle Ages, such and similar apparatus (“girdles of chastity”) are said to have been employed for the protection of the honour of an absent husband.

Of gynecologists who have advised operative measures for the prevention of pregnancy, in women in whom that condition involved serious dangers, the first, as far as I know, was Blundell. As a result of experiments made on rabbits, he suggested division of the Fallopian tubes as the best way of attaining this end. Later, Froriep and Kocks also endeavoured to induce artificial sterility in women by occlusion of the Fallopian tubes. Froriep’s idea was to bring about obliteration of the lumen of the tubes by means of cauterization with nitrate of silver; Kocks constructed for the same purpose a galvano-caustic uterine sound. But, in the first place, both the methods advocated are too uncertain to be relied upon; and, in the second place, their application is neither easy, nor devoid of serious risk.

Much more effective, however, is the method recommended by Kehrer for the sterilization of women, namely, division of the Fallopian tubes by the vaginal route. Kehrer considers that the physician is justified in preventing the occurrence of pregnancy in a number of morbid conditions—incurable nervous, cardiac, pulmonary, gastric, and renal disorders; various constitutional affections; and, finally, in cases of pelvic deformity of such a degree that the delivery of a living child is impossible except by means of Cæsarean section, but the patient does not wish to be exposed to the risks of this operation. He believes, moreover, that all the methods commonly recommended for the prevention of pregnancy are untrustworthy. So powerful, however, is the sexual impulse, that, as experience shows, the mere prohibition of sexual intercourse, however earnestly made, invariably proves ineffectual. For coitus interruptus to be effective, the interruption must occur at the right moment; and this does not always take place. Cold water douches after coitus are unhygienic; douches of warm water, medicated with sublimate, alcohol, and other drugs lethal to the spermatozoa, are indeed rationally conceived, but often fail of their effect, either because they are deferred until too late, or else because they fail to irrigate all parts of the vagina. Plugs of cotton wool, 418sponges, etc., are not always introduced in such a way as effectually to occlude the vaginal passage. A suitable and properly introduced occlusive pessary is, indeed, a relatively trustworthy preventive apparatus, but if worn continuously it is apt to become very foul. A thorough douching of the genital passage with an antiseptic solution, performed by the skilled hand, immediately after coitus, would doubtless destroy the spermatozoa with the like certainty with which the same procedure destroys micro-organisms when performed prior to a gynecological operation—but when carried out by the layman, the value of the method is more than doubtful. The operation, for a time actually fashionable, of extirpation of the uterine annexa, certainly gives rise to sterility, but entails the serious disadvantage that the consequent premature menopause is attended by the same disturbances as the natural change of life. On the other hand, section and ligature of the Fallopian tubes is considered by Kehrer to induce sterility without in any other way disturbing the functions of the female reproductive organs. By means of anterior colpotomy we obtain a suitable route for the ligature and section of both tubes at the isthmi. When carried out with the proper antiseptic precautions the operation is almost entirely free from risk; and when the organs are healthy the closure of both the upper and the lower segments of the tubes is effected, and no retention of secretions need be feared as a result of the operation.

With regard to the indications for the performance of this operation, Kehrer insists that it should be undertaken only in cases of serious disease, and when the pros and cons have been conscientiously weighed. A consultation is also indispensable. Moreover, it is essential that husband and wife should both fully understand the nature of the proposed operation, and should form an unbiassed judgment regarding its advisability. To avoid any possibility of subsequent reproaches, Kehrer advises that a written report should be drawn up, giving the reasons for undertaking the sterilization, and that this should be subscribed by the physicians in consultation, by the patient herself, and by her husband.

Arndt considers that in cases in which there already exists serious constitutional disease, the performance of this operation may lead to fever, severe hæmorrhage, injury to adjacent organs, and even death. He holds, therefore, that in such cases the physician should advise the use of some of the more ordinary methods of preventing conception (if simple abstinence from intercourse cannot be practised). Only in women with pelvic contraction of the 419second or third degree, in whom previous children have been still-born, or subjected to craniotomy, is operative sterilization by Kehrer’s method justifiable. But in preference to anterior colpotomy, as recommended by Kehrer, he prefers the longitudinal incision in the posterior vaginal fornix advised by Boileux. If the uterus is drawn down firmly, and the portio vaginalis then pushed forward against the pubic symphysis, it is easy, at any rate with the assistance of a little abdominal pressure, to draw part of the Fallopian tubes into the vaginal incision.

Recently Pincus has recommended the cauterization of the uterine cavity with superheated steam (atmocausis, castratio uterina). He advises it only in women who are incurably ill (tuberculosis, morbus Brightii, hæmophilia), so that pregnancy and parturition would involve almost certain death.

Kossmann considers that when pregnancy and parturition will endanger a woman’s health and life, it is the physician’s duty to acquaint both husband and wife with this fact; but having done so his duty is fully discharged. “If, after being warned, the married pair choose to indulge in sexual intercourse, they have knowingly and voluntarily run into danger, and for this the physician is in no way responsible.”

As indications for facultative sterility Levy enumerates tubercular disease of the lungs, mental disorders, severe organic or functional diseases of the central nervous system, active syphilis (in certain circumstances), pernicious anæmia, hæmophilia, diabetes mellitus, severe heart disease, chronic disease of the kidneys or liver, certain pelvic deformities, and the tendency to habitual abortion.

I have myself before now stated my opinion that it is the duty of the physician, in the case of a married woman suffering from heart disease, with due regard to the danger which pregnancy will entail upon her, to give needful advice in the matter of the prevention of conception. In women affected with valvular heart disease, and in whom there are serious disturbances of compensation, conception is absolutely to be avoided; also in conditions of marked cardiac degeneration, and when there are distinct symptoms of insufficiency of the heart muscle. When, on slight exertion, palpitation, increased frequency of the pulse, and respiratory need (“air-hunger”), ensue; when there is extensive œdema of the lower extremities which persists even after confinement to bed; when the pulse readily becomes arhythmical both in respect of the strength and the temporal succession of the beats; when the urine 420is scanty and contains varying quantities of albumen; when there are frequent attacks of heart-weakness, with a small irregular pulse, coldness of the extremities, a cyanotic tint of complexion, nausea, dyspnœa, sense of faintness, or actual syncope—in all such cases, whether dependent upon valvular disease, on pathological changes in the arteries, or upon disease of the myocardium, the occurrence of pregnancy is a true disaster, giving rise in most cases to a grave aggravation of the heart trouble and often enough costing the patient her life. I further regard it as a sound medical axiom that in cases of cardiac disorder of a less severe type than that just described the woman thus affected should not have more than one or two children. This is the more necessary because with each successive pregnancy the functional capacity of the diseased heart decreases in geometrical progression and the danger to life proportionately increases. But in such cases of heart disease the prevention of pregnancy must never be effected by the interruption of coitus by the man before ejaculation, for the reason that this procedure gives rise to manifold reflex cardiac troubles, and especially to paroxysms of tachycardia, with simultaneous diminution in vascular tone, vasomotor disturbances, and states of mental depression—and these entail exceptional dangers in women suffering from heart disease.

The Determination of Sex.

The problem of the determination of sex in the human species is one which has occupied natural philosophers from the very earliest times, and has always greatly interested all classes of the population.

The interest awakened by the subject depends principally on the fact that female children have usually been less desired than male in all periods of history and among almost all races. In the uppermost circles of society the truth of this statement is manifested by the fact that the birth of a prince is announced by a salute of 101 guns, that of a princess by a salute of 35 guns only.

It would serve no useful purpose to transcribe here the opinions, or rather guesses, which were ventured on this topic in earlier days when the very nature of the reproductive process was still entirely unknown, and we shall merely mention that the curious will find various references to the determination of sex in the works of Hippocrates, Aristotle, Plutarch, Soranus, Susruta and Galen.

421Broadly speaking, the earlier theories may be said to diverge in two main directions, some holding that the sex of the infant was in some way determined by the mode of intermixture of the male and the female elements in the act of generation, and others maintaining that sex was already inalterably predetermined at the time of intercourse either in the male or in the female sexual elements.

Pari passu with the modern development of the theory of evolution, and with the enormous increase in recent days in anatomical and physiological knowledge, the theory of the determination of sex has been very widely extended. The rival views may be briefly arranged in the four following categories:

I. That sex is already inalterably predetermined in the ovum, upon the constitution of which it solely depends; there are therefore male and female ova, and the process of fertilization exercises no influence whatever upon the determination of sex. The alternative theory to the above, that sex is determined solely by the constitution of the fertilizing spermatozoon—i. e., that the spermatozoa, and not the ova, are male and female, respectively—is one which in recent years has tended more and more to disappear from the field.

II. That sex is determined in the moment of fertilization by the reciprocal interaction of male and female, of zoösperm and ovum. One variant of this theory maintains that each reproductive element strives for the reproduction of its own sex; that a struggle takes place and that the victor in the contest stamps its own sex-likeness upon the fertilized product. According to another view, however, sex is not directly transmitted in this manner; it is supposed that the more powerful the proper reproductive element (according to this theory the ovum) the more strongly does it tend to determine the reproduction of a stronger, i. e., a male organism; thus the greater potency of the female element in the act of reproduction tends to favour the determination of the male sex.

III. That sex is not determined until after fertilization, during the early stages of the development of the embryo; the determining causes are supposed to be various factors capable of influencing the developing organism during this period, and more particularly the nutritive conditions of the mother.

IV. That the determination of sex is not dependent solely upon the action of any single one of the factors above enumerated, but arises as a resultant effect of the operation on the germ of all three of these acting in temporal succession.

422Modern physiology has endeavoured to solve this problem by statistical investigations, by anatomical demonstration, and finally by experiment.

I. Statistical Investigations.

Statistical data have been collected showing the ratios between male and female births in the most varied conditions possible, and from these data the attempt has been made to draw valid conclusions regarding the causes of the determination of sex. Now in the first place it is above all necessary to bear in mind that such statistical data cannot possibly have any value unless they relate to very numerous instances, and even then they are liable to be invalidated by various sources of fallacy. We may with advantage quote in this connection the remarks of Hensen in his work on the “Physiology of Reproduction:” “Each individual instance is rendered unique in kind by the interaction of certain incommensurable elements; for instance the state of health of the individual organs in their innumerable combinations, variations in the general health of the parents, the frequency of coitus and the time at which it took place, the desire of the parents to have a son and then no more children, their social position—in these ways innumerable complications are introduced into the problem, and the difficulty of drawing valid conclusions is rendered almost insuperable, unless the number of instances dealt with is enormously large.”

One fact definitely established is that more boys are born than girls, the proportion between the two, known as the sexual ratio, being 106 : 100. Statistics relating to the half of Europe (Oesterlen) and dealing with 59,350,000 births, showed a ratio of 106.3 male to 100 female births; in individual countries variations from this mean are found to occur, but these are not very extensive, the highest ratio being 107.2 : 100, and the lowest ratio 105.2 : 100.

From the works of Hofacker (“Ueber die Eigenschaften welche sich bei Menschen und Tieren von den Eltern auf die Nachkommen vererben”—Concerning the Qualities transmitted from Parents to Offspring in Men and Animals—Tuebingen, 1828) and Sadler (“Law of Population,” London, 1830) conclusions have been drawn regarding the effect of a variation in the age ratio of the parents on the determination of sex. The deductions in question, known as Hofacker and Sadler’s law, are as follows:

1. If the husband is older than the wife more boys are born than girls.

4232. If husband and wife are the same age somewhat fewer boys are born than girls.

3. If the wife is older than the husband the excess of female births is larger still.

Hofacker’s actual figures were the following:

Father younger than mother 90.1 boys to 100 girls.

Father same age as mother 93.3 boys to 100 girls.

Father 4 to 6 years older than mother 108.8 boys to 100 girls.

Father 6 to 9 years older than mother 124.7 boys to 100 girls.

Father 9 to 12 years older than mother 143.7 boys to 100 girls.

Sadler’s results were closely similar:

Father younger than mother 86 boys to 100 girls.

Father same age as mother 94 boys to 100 girls.

Father 1 to 6 years older than mother 103 boys to 100 girls.

Father 6 to 11 years older than mother 126 boys to 100 girls.

Father 11 to 16 years older than mother 147 boys to 100 girls.

Father 16 years and more older than mother 163 boys to 100 girls.

Goehlert found that the offspring of marriages in which the husband was younger than the wife were 71 boys and 86 girls; of marriages in which husband and wife were of the same age, 263 boys and 282 girls; and of marriages in which the husband was older than the wife, 2,017 boys and 1,865 girls.

Wappaeus, combining the data supplied by these three investigators, Hofacker, Sadler and Goehlert, obtained the following sexual ratios for the entire 8,000 cases (i. e., the number of boys born to each 100 girls born): When the husband was younger than the wife, 88.2; when husband and wife were of the same age, 93.5; when the husband was older than the wife, 113.0.

It will be observed that the mean sexual ratio of these 8,000 cases is 109.6; whilst, as we saw above, when a sufficiently large number of instances is taken, the sexual ratio always closely approximates to 106.3. From this it appears that the numbers dealt with by Hofacker, Sadler and Goehlert in their investigations were too small for the deduction of trustworthy averages.

The same criticism is applicable to the observations of Ahlfeld, Breslau and Noirot, whose results conflict with those just given. According to Ahlfeld, in the case of 1,376 births where the father was at least 10 years older than the mother, the sexual ratio was only 98.2. According to Noirot’s data, in cases in which the father was older than the mother, this ratio was 99.7.

424Oesterlen gives the following brief summary of the researches made for the establishment and confirmation of the law of Hofacker and Sadler:

Author. Father older than mother. Father and mother same age. Mother older than father. Sexual ratio. Number of instances.

Hofacker 117.8 92.0 90.6 107.5 1,996

Sadler 121.4 94.8 86.5 114.7 2,008

Goehlert 108.2 93.3 82.6 105.3 4,584

Noirot 99.7 116.0 103.5 4,000

Legoyt (Calais) 109.9 107.9 101.6 107.9 6,006

Legoyt (Paris) 104.4 102.1 97.5 102.9 52,311

Breslau 103.9 103.1 117.6 106.6 8,084

The law of Hofacker and Sadler cannot be regarded as possessing universal validity, although the figures on which it is based seem to show pretty clearly that we are justified in regarding the mutual interaction of the male and female reproductive elements at the moment of fertilization as effective in the determination of sex. In the investigations to which we have hitherto alluded it is only the relative ages of husband and wife that have been taken into account; but other researches have shown that the absolute age alike of the husband and of the wife has an influence in the determination of sex.

The influence of the absolute age of the mother in the determination of sex has been very clearly established. Ahlfeld was the first to draw attention to the fact that among the children of elderly primiparæ there was always to be found an excess of boys, and that there was an increase in this excess proportionate to the greater age of the mother. Among 102 children born to primiparæ over 32 years of age the sexual ratio was 137 : 100; and a later investigation made by the same author in conjunction with Schramm showed that among 1,038 children born to primiparæ over 28 years of age the sexual ratio was 124 : 100.

Hecker obtained similar results. Among 432 children born to primiparæ over thirty years of age the sexual ratio was 133 : 100. Winckel, dealing with primiparæ of the same ages, found a sexual ratio of 136.8 : 100.

Düsing, examining the records of the lying-in hospitals of Leipzig, 425Dresden and Jena and thus obtaining a very large number of instances whereon to base his conclusions, confirmed the view that elderly primiparæ give birth to an excess of boys, and further that the older they are the larger the excess of male births. He drew up the following table:

Age of primiparæ. Leipzig. Boys. Girls. Dresden. Boys. Girls. Jena. Boys. Girls. Total Nos. Boys. Girls. Sexual ratio.

15 1 : − 1 : 2 1 : − 3 : 2 549 : 494 = 111.1

16 4 : 4 6 : 10 2 : 2 12 : 16

17 23 : 13 20 : 15 9 : 7 52 : 35

18 67 : 55 103 : 100 17 : 13 187 : 168

19 110 : 103 152 : 141 33 : 29 295 : 273

20 148 : 147 187 : 185 32 : 45 367 : 377 807 : 781 = 103.3

21 157 : 145 241 : 201 42 : 57 440 : 404

22 120 : 133 191 : 207 48 : 53 359 : 393 903 : 962 = 93.9

23 106 : 108 168 : 149 51 : 51 325 : 308

24 71 : 105 111 : 118 37 : 38 219 : 261

25 79 : 57 73 : 72 35 : 27 187 : 156 531 : 469 = 113.2

26 45 : 35 30 : 43 20 : 20 125 : 98

27 31 : 35 52 : 55 10 : 12 93 : 102

28 32 : 33 26 : 33 19 : 16 77 : 72

29 19 : 10 26 : 18 4 : 13 49 : 41

30 9 : 15 30 : 13 9 : 6 48 : 34 155 : 104 = 150.0

31 3 : 8 15 : 11 3 : 3 21 : 22

32 5 : 6 12 : 9 7 : 3 24 : 18

33 2 : 2 5 : 5 5 : 2 12 : 9

34 4 : − 8 : 5 2 : − 14 : 5

35 2 : − 9 : 3 2 : 1 13 : 4

36 1 : − 3 : 3 1 : 1 5 : 4

37 4 : 1 4 : 3 1 : − 9 : 4

38 − : − − : 1 1 : − 1 : 1

39 − : − 4 : − 1 : − 5 : −

40 1 : 1 2 : 1 1 : − 4 : 2

41 − : − − : 1 − : − − : 1

As an explanation of this statistically proved fact, that elderly primiparæ gave birth to a large excess of boys, Düsing suggests that these women who conceive for the first time comparatively late in life, are, prior to the conception, in a state corresponding with that of a lower animal species suffering from a deficiency of males, and for this reason exhibit a tendency to procreate a larger number of individuals of the deficient sex. In multiparæ also it is possible to trace the influence of a deficiency of male individuals. When there is such a deficiency the interval between successive births is unduly protracted. Düsing found (once more from the records of the lying-in hospitals of Dresden, Leipzig and Jena) that the longer 426the interval between one parturition and the next the longer, that is to say, the mother has had to wait for her next conception, the greater is the excess of male births. Düsing therefore lays down the law: “Delayed impregnation gives rise to an excess of male births.”

Age of primiparæ. Leipzig. Boys. Girls. Dresden. Boys. Girls. Jena. Boys. Girls. Total Nos. Boys. Girls. Sexual ratio.

1 162 : 158 194 : 178 58 : 45 414 : 381 108.6

2 366 : 307 374 : 361 168 : 145 908 : 813 111.6

3 198 : 196 207 : 194 116 : 94 521 : 484 107.7

4 127 : 109 132 : 106 59 : 45 318 : 260 115.7

5 59 : 54 55 : 54 38 : 38 152 : 146

6 61 : 62 52 : 49 49 : 24 162 : 135 121.9

8, 9 and 10 18 : 16 41 : 23 16 : 24 75 : 63

11 and more 5 : 15 12 : 9 4 : 6 41 : 30

Totals: 4,903 births, 2,591 m.; 2,312 f.; sexual ratio = 112.06.

Bidder considers that his own observations entitle him to modify Ahlfeld’s dictum regarding the influence of age in primiparæ in giving rise to an excess of male births. He tabulates his results as follows:

Age of Mother. Number of cases. Sexual ratio.

17 to 20 80 122.2

20 to 22 405 130.1

22 to 24 369 109.9

24 to 26 1,138 104.6

26 to 30 2,049 105.5

30 to 32 878 112.5

32 to 36 1,120 119.6

36 to 39 676 123.1

40 and upward 215 131.5

and formulates the following thesis: Very young primiparæ give birth to an excess of boys; primiparæ in the first bloom of womanhood give birth to an excess of girls; later, however, as the age of the primiparæ increases the excess of male births soon reappears and rapidly increases.

Hofacker’s data and the researches of Hampe agree with those of Bidder in showing that to very young primiparæ, as well as to 427elderly primiparæ, an excess of boys is born. Among the offspring of 363 mothers, at ages varying from 16 to 26 years, Hofacker found the sexual ratio to be 121; among the offspring of 1,056 mothers, at ages 26 to 36, the ratio was 101; and among the offspring of 567 mothers at ages 36 to 46, the ratio was 111. Hampe tabulated 5,992 instances as follows:

Age of Mother. Number of instances. Sexual ratio.

Below 20 years 56 107.7

20 to 25 years 871 90.6

25 to 30 years 1,633 114.9

30 to 35 years 1,631 108.3

35 to 40 years 1,185 117.1

Over 40 years 616 124.0

We learn, therefore, that if the age of the progenitors is to be regarded as one of the causes by which sex is determined, we must take into consideration not only the relative ages of husband and wife but, in addition, the absolute age of the wife.

Goehlert undertook a statistical investigation in which the absolute age of the husband was taken into consideration as well as that of the wife. From this it appeared that the maximum sexual ratio was exhibited when the father was between the ages of 30 and 35 years. When the age of the mother is treated as the determining influence, we find the maximum sexual ratio in the offspring of mothers between the ages of 25 and 30 years. Goehlert believes, however, that the paternal influence is more powerful than the maternal in the determination of sex. The respective influences are compared in the following table:

Age of Father. Age of Mother.

20 to 30 years. 30 to 40 years. Over 40 years. Totals.

25 to 35 years 105.76 107.87 109.14 106.6

35 to 45 years 102.8 105.1 105.3 104.7

Over 45 years 104.3 103.9 109.1

In general 105.25 105.97 104.9 105.5

428Geissler, studying the data obtainable regarding the sexual ratio during a 10–year period in the Kingdom of Saxony, ascertained that in families possessing two children or more there was a very definite distribution of the possible sex-combinations. Where there was an even number of children those families were in the majority in which the number of boys and girls was identical. If the number of children in the family is an unequal one, those combinations are most frequent in which the number of boys exceeds the number of girls by one; next in frequency are those combinations reversed to this, i. e., in which the number of girls exceeds the number of boys by one. All other combinations are comparatively infrequent in proportion as the discrepancy in number between boys and girls is larger. Rarest of all are families in which the children are all of the same sex; and among these, again, the most unusual are those consisting of boys only.

This distribution of the sex-combination is believed by Geissler to depend upon the fact that in the first birth and all the subsequent births there is generally speaking a slight advantage in favour of the male sex. It has not been proved that the sex of the first-born exercises a determining influence on the sex of the subsequent children. It does, however, seem clear that in the case of parents who have given birth in succession to several children of one sex only, there exists some definite obstacle to the procreation of children of the opposite sex. Putting these exceptions out of consideration, there seems to exist a tendency in the later births of a series toward the procreation, more especially of that sex which has been absent or deficient in the earlier births of the series. The strength of this equalizing tendency increases as soon as it has for the first time manifest itself. It is always greater when the sex deficient in the earlier births of the series has been the male.

I have myself undertaken a statistical investigation of the births occurring in the reigning families of Europe and in the families of the leading members of the aristocracy. The necessary particulars are to be obtained from the genealogical court calendars; and it is my belief that the data obtained regarding these uppermost strata of society are comparatively free from many sources of error by which the ordinary statistics of the subject are apt to be invalidated. For 556 marriages there were 1,972 births, comprising 1,023 boys and 949 girls, and thus exhibiting a sexual ratio of 107.7.

In relation to the relative ages of the parents, the following table was drawn up:

429

Boys. Girls. Sexual ratio.

Husband older than wife by one to five years 294 283 103.8

Husband older than wife by more than five and less than ten years 327 306 106.8

Husband older than wife by more than ten and less than fifteen years 190 167 113.7

Husband older than wife by more than fifteen years 138 113 122.1

Husband same age as wife 34 42 80.9

Husband younger than wife 40 38 105.2

From these figures we may deduce the following conclusions, which are not wholly concordant with the law of Hofacker and Sadler: When the husband is older than the wife the excess of male births among the offspring is greater than it is in the case of an average drawn from the offspring of all marriages (in my cases the difference was 111.8 as compared with 107.7). But a closer analysis shows the difference to be less simple than at first sight appears. If the husband is older than the wife by one to five years, the excess of male births among their offspring (103.8) is less than in the average of all marriages (107.7); the same is true of the offspring of marriages in which the husband is more than five and less than ten years older than the wife, though the difference here is very trifling (106.8 as compared with 107.7). It is not till we come to the offspring of marriages in which the husband is from ten to fifteen years older than the wife that the increase in the excess of male births becomes notable (113.7 as compared with 107.7); and when the husband is more than fifteen years older than the wife the excess of males is higher still (122.1).

If we arrange these data so as to show, in cases in which the husband is older than the wife, the additional influence of the absolute age of the wife, we obtain results which partially conflict with those of Bidder, as follows:

Husband Older than Wife. Boys. Girls. Sexual ratio.

Wife’s age, 15 to 20 years 280 287 97.6

Wife’s age, 20 to 26 years 595 513 116.0

Wife’s age, 26 to 33 years 74 69 110.1

430Thus we see that when the wife is very young, i e., less than twenty years of age, even though the husband is older than the wife, there is among their offspring no excess of male births, but the contrary—a sexual ratio of 97.6 only. Most marked is the excess of boys in cases in which the husband is older than the wife, and the age of the wife is from twenty to twenty-five years. When the husband is older than the wife, and the wife’s age lies between twenty-five and thirty-two years, the excess of male births is not so great, though still considerable.

Hence it appears that the law of Hofacker and Sadler, which cannot be regarded as fully valid in the terms in which it was originally expressed, must be modified as follows: If the husband is at least 10 years older than the wife, and the latter is at an age when her reproductive capacity is at its maximum (twenty to twenty-five years), the offspring exhibit a notable excess of male births. There is still a considerable excess of male births in the offspring of marriages in which the husband is at least ten years older than the wife, and the wife is more than twenty-five years of age. On the other hand fewer boys are born than girls as the offspring of marriages in which, although the husband is older than the wife, the wife has not yet attained the age of maximum reproductive capacity—i. e., is less than twenty years of age. The excess of female births is most marked when the husband and wife are of the same age. When the wife is older than the husband there is a moderate excess of male births.

I admit, however, that the figures upon which I have based these conclusions are, like those of Hofacker, too few in number for the foundation of trustworthy inferences. The instances in my computation number 1,972; those in that of Hofacker, 1,996; but, as I have already remarked, there are reasons for believing that the data I have employed admit of the introduction of fewer sources of error.

The influence of the absolute age of the mother in the determination of sex having been statistically proved, many have inferred that this determination is not effected during the instant of fertilization, but occurs at a later stage of intra-uterine life, and is influenced by the manner in which the embryo is nourished by the maternal organism. It is suggested that elderly and immature mothers are unable to furnish the embryo with nutriment so well as those mothers who are at the age of maximum reproductive capacity, and that upon this fact depends the excess of male births 431in the latter case. (We shall return to this matter—the influence of deficient nutrition in relation to the excess of male births). But the proof of the fact that the absolute age of the father has also an influence in the determination of the sex of the offspring offers a ground for opposing this assumption that the sex of the embryo is determined during intra-uterine life subsequent to fertilization, and suggests that the father also exercises a determining influence in the origination of sex during the act of fertilization.

The absolute age of the husband seems also to have some influence upon the sexual ratio. The absolute age, like the relative age, of the father appears favourable to the procreation of a greater excess of boys. Thus, Hofacker found in 1,193 cases, in which the age of the father was from twenty-four to thirty-six years, that the sexual ratio was 100; in 683 cases in which the age of the father was from thirty-six to forty-eight years, the sexual ratio was 114; and in 105 cases, in which the age of the father was from forty-eight to sixty years, the sexual ratio was 169.

In investigations based upon larger collections of cases Schumann and Düsing have endeavoured to determine the variation in the sexual ratio according to the absolute age of the father.

Düsing examined the statistics of births in Norway, Alsace-Lorraine and Berlin, and from the data thus obtained he compiled the following table:

Age of Mother. 30 to 35 Years. 25 to 30 Years. 20 to 25 Years.

Age of Father. Boys. Girls. Sexual ratio. Boys. Girls. Sexual ratio. Boys. Girls. Sexual ratio.

15 to 30 years 8,525 7,887 108.1 27,389 25,843 106.0 21,560 20,330 106.0

30 to 35 years 23,283 21,823 106.9 23,394 23,486 103.9 7,954 7,469 106.5

35 to 40 years 17,885 17,070 104.7 10,272 9,838 104.2 2,426 2,416 100.4

40 to 45 years 7,972 7,681 103.8 3,165 3,058 103.5 1,154 1,100 105.0

Over 45 years 4,220 3,997 105.6 1,734 1,525 113.8

In this table we find the births arranged in relation to varying ages of the fathers and in relation to mothers whose ages are tabulated in three classes, the ages of the latter being those at which they are most prolific. The table shows clearly that the excess of boys is larger at the beginning and at the end of each column. Thus, the age of the mother remaining constant, young fathers and elderly fathers procreate a larger proportion of boys than do fathers of intermediate age.

432But I find in this table, which is based upon a very large number of instances indeed, a confirmation of the thesis which I stated above, for the highest sexual ratio of 113.8 is in this table found in the case of fathers over forty-five years of age who are married to mothers of ages twenty-five to thirty years; this is, as I said, the case in which “the husband is at least ten years older than the wife, and the latter is at the age at which her reproductive capacity is at its maximum.”

From such figures as these, which seem to show the influence of the absolute age of the father upon the determination of sex, it has by many been inferred that the man exercises a preponderating influence upon the determination of the sex of the embryo, impressing his own sex upon it, and that the greater the sexual potency of the begetter the more powerful also is the influence exercised by the latter; that the point of first importance in this connection is the sexual capacity of the man; and that the excess of male births increases pari passu with the increase in the potency of the procreating male.

Two additional considerations have been adduced to demonstrate the influence of the father in determining the sex of the offspring. The first of these is a comparison of the ratio between male and female births in towns and in rural districts, respectively; and the second is a comparison between the ratio of males to females in the offspring of married and of unmarried parents, respectively.

In towns the excess of male births is smaller than it is in the country. The average sexual ratio in Prussia during the five-year period, 1875 to 1880, is given by Düsing as follows:

In Berlin 105.70

In other large towns 105.72

In medium sized towns 105.44

In small towns 106.17

In rural districts 106.62

The indisputable fact that in towns more girls are born than in rural districts is referred to the fact that in the country the husband usually enters on marriage with his virile powers completely unimpaired, whereas in towns many men only marry after they have for many years expended their best forces in irregular sexual intercourse, and thus reserve for their wives only the dregs. But, as we shall show presently, the difference between town and country in this respect is susceptible of a different interpretation.

It has also been asserted (Horn) that extra-conjugal sexual intercourse is favourable to the procreation of boys, the suggestion 433being that the greater sexual vigour in the former case determines a preponderance of males in the offspring; but this assumption is invalidated by the statistical evidence which now accumulates, that among illegitimate offspring there is a smaller excess of boys than among legitimate offspring. Babbage, for instance, came to this conclusion as a result of the comparison of 1,000,000 illegitimate births with 14,000,000 legitimate births. On the other hand, the following utterance of Ploss appears extremely artificial: “In a country in which illegitimate births are very numerous, in which the illegitimate children are for the most part begotten by enervated debauchees, the excess of male births is smaller; but in a country in which the illegitimate births are less numerous, and in which the illegitimate infants are for the most part the fruit of love and are begotten by youthful lovers, the excess of male offspring is larger.”

Next to the age of the progenitors, their nutritive condition is shown by statistical investigations to exercise an important influence in the determination of sex. The following proposition has, in fact, been established: Where the supply of nutriment is deficient, the offspring contains an excessive proportion of boys.

Ploss, in an article on “The Causes of Variations in the Sexual Ratio,” published in twelfth volume of the “Berliner geburtsh. Monatsheft,” has collected a number of statistical data to demonstrate that the determination of sex is principally dependent upon the nutritive condition of the mother. In his opinion the determination of the sex of the embryo depends neither upon the quality of the ovum nor upon that of the spermatozoon, nor again upon the reciprocal influences exerted by ovum and spermatozoon on one another. During the earliest time after fertilization the embryo is sexually neutral and only later, as a result of some new influence acting upon it, does it receive an impulse toward the formation either of the male or of the female sex. Among all the external conditions which are capable during this period of exercising a determinative influence the most important are the nutritive conditions, for nutrition is the most important factor in determining the form of the young animal, and most of the other outward conditions, such as light, heat, and chemical changes, affect the embryo in a mediate manner only, through the changes they are respectively capable of inducing in its nutrition and metabolism. But Ploss is not content with asserting that the nutritive condition of the mother is of great importance in determining the sex of the embryo; he goes further than this, and declares that it is scanty 434nutrition of the mother which especially gives rise to the birth of males, whereas abundant nutrition of the mother tends to give rise to the birth of females. He refers to observations made in respect of other animals than man. St. Hilaire observed that among the underfed animals in menageries there was an excess of male births. Hofacker and Girou de Bazarcingues have noted similar phenomena in the case of domestic animals; they found that when these were richly fed they gave birth to an excess of females, but that when they were poorly nourished they gave birth, on the contrary, to an excess of males. Among sheep, with whom the number of male and of female births is approximately identical, Martegoute found that those animals which had given birth to female lambs had on the average a greater weight than those ewes which had given birth to male lambs. During the period of lactation, also, the former lost weight more than the latter.