Another slight obstacle to conception on the part of a woman which is not infrequent is the position of the mouth of the womb and the relation of the vaginal canal, which may be such that the spermatic fluid tends to be lost without any of it penetrating the orifice of the womb itself. To overcome this it is often sufficient for the woman to turn over directly the act of union is complete and lie face downwards for a few hours.

Without any question, all women have times of greater or less reproductive vitality, but in some women this is less marked than in others, and with some conception may take place at almost any date in the menstrual month; but with other women there is a group of days ranging from three or four to a dozen or more, in which conception seems to be impossible; while, on the other side of this group of neutral days, the days grade upwards towards a date of greater reproductive potency. Therefore, a woman and her husband who desire children, but have not after some years of marriage had the good fortune to attain parenthood, should choose for their acts of union those days on which conception is most likely. It is generally found that the most certain date for conception is--with very few exceptions-- about the last day of the monthly period, or the day or two immediately after it; so that the husband who ardently desires his wife to conceive should, with her consent, concentrate their unions so far as possible on such dates.

On the other hand, it must not be forgotten that the effect on the whole nervous system of the desire to conceive is very great. A too frantic desire, which leads to too frequently repeated unions, will probably defeat itself, because it is not the mere coalescence of the sperm with the ovum which completes conception, it is also the attachment of that impregnated ovum to the wall of the womb, and intense nervous excitement may prevent that. Indeed, it has been stated by a medical man of considerable weight in the last century that there are women among those races to whom sex-knowledge is not taboo who can voluntarily control conception at will and consciously expel an impregnated ovum by mere exercise of nervous force. A woman in modern society who is in a highly nervous condition, which may find expression in her constant need of cigarettes or excitement, may be (though this is by no means universally true) frequently impregnated and at the same time continually throwing off the impregnated ovum before the settling down of that ovum, which results in true conception, can take place. If, therefore, the woman who urgently desires to be a mother finds herself continuously smoking, or notes in herself any other indication of a lack of placidity in her nerves, she would do well--not merely to restrict her smoking, which is nothing but a symptom of a deeper need--but she would do well to restore so far as possible a calm poise to her whole system by longer sleep, more country air, plenty of fresh butter, or whatever simple remedy it may be that will supply her nerves with something lacking, and for which she is unconsciously craving.

Although to many it may seem incredible, yet it is not so rare as might be supposed, that the adult pair may be married for years, and the wife still physically a virgin owing to neither of the pair knowing that penetration must be effected. Amazing as it may seem, four or five such cases, all of intelligent apparently average people, have come to my direct knowledge in the course of one year alone. Another cause, less extreme, is due to the woman making full entry difficult or impossible by not taking up a proper position during union. (See also p. 114.) In such cases a knowledge of the true details involved may speedily bring the desired conception. »

These very simple suggestions are of the kind often overlooked by the medical specialist, to whom a woman goes tremblingly asking if she is abnormally formed in any way, because she does not get the children she so much longs for. Such advice, of course, will apply only'to people who are essentially normal and without deformity. For more serious obstructions to parenthood, the pair, and not the woman only, should seek medical advice.

Note i.--(See p. 24.)

For suffering and even death of unmated females, see e.g. MARSHALL, in Quarterly Journal Microscopical Society, Vol. 48, 1904, p.323.

PARSONS, in British Medical Joumal, October, 1904. Note 2.--(See p. 31.)

A frequent mistake (made even by gynaecologists') is to confuse menstruation with the " period of desire," which is generally called " heat" in animals. Even in the most authoritative recent text books, such phrases as " heat and menstruation " are very common, thus coupling heat and menstruation as though they were equivalents, while the older books quite explicitly look on the menstrual period in women as corresponding to desire of " heat" in animals. This error has even been repeated very recently in the Proceedings of the Royal Society of Medicine.*

Some physiologists, have studied this subject in several of the higher animals, and now realise that the time of desire is physiologically distinct from the phase which is represented by menstruation in women. It seems to be fairly well established that in women menstruation is caused by an internal secretion of the ovaries (c.f. p. 61), and is not directly due to ovulation, though it must have some connection with it.f

The most that modern science appears to have attained is briefly summarised in the following quotation from Marshall ("The Physiology of Reproduction," p. 69):

* See Dr. Raymond Crawfurd's mistaken statement that " the identity of oestrus, or ' heat ' in the lower animals and of menstruation in the human female, admits of no doubt." P. 62 Proc. Roy. Soc. Medicine, vol. 9., 1916. * f The best modern account of these complex subjects will be found in the advanced text-book, " The Physiology of Reproduction," pp. xvii., 706, by F. H. A. Marshall. Reference may be made to original papers by J. Beard in the Anat. Anzeiger for 1897; and by Heape in the Philosophical Trans. Royal Society, 1894, 97.

" According to Martin and certain other writers, the hum*n female often experiences a distinct post-menstrual oestrus [Modern research has recognised a period when the female animal is ready tor impregnation, which is called the ccstrus, and a preparatory series of physiological changes called the pro-estrous phase.--M.C.S.], at which sexual desire is greater than at other times; so that, although conception can occur throughout the intermenstrual periods, it would seem probable that originally coition was restricted to definite periods of oestrus following menstrual or pro-estrous periods in ivomen, as in females of other mammalia. On this point Heape write as follows : ' This special time for cestrus in the human female has very frequently been denied, and, no doubt, . modern civilisation and modern social life do much to check the natural sexual instinct where there is undue strain on the constitution, or to stimulate it at other times where extreme vigour is the result. For these reasons a definite period of oestrus may readily be interfered with, but the instinct is, I am convinced, still marked.' "

In nearly all wild animals there is" a definite period for sexual excitement, very commonly just at that time of trie year which fits into the span of gestation,' so that the young are born at the season which gives them the best chance to grow up. In animals the period of desire, the ovulatfon (or setting free of the female germ or unfertilised egg-cell) and the time of the birth of the young, are all co-related harmoniously. The male animal is only allowed to approach the female when the natural longing for union is upon her. , Among human beings, the only race which seems to have long periods of sexual quiescence at all comparable with those natural to the animals are the Esquimaux, who appear to pass many months without any unions of the men and women.