Fecundity

“ As the average duration of a woman's fecundity is about twenty-five years, and as the mean duration of pregnancy and lactation is eighteen months, it follows that a healthy woman can give birth to sixteen children, but examples are not wanting in which, in consequence of plural births or of prolonged periods of fecundity, as many as twenty-four children have resulted from a single marriage. ”

“ It is said that the dissemination of venereal diseases has caused an increase of sterility; that luxurious living lowers fecundity, and so on. It is impossible to take the time to analyze the many explanations of this sort which have been offered, and which are familiar to the reader; we must content ourselves with saying that evidence of a great many kinds, largely statistical and, in our opinion, reliable, indicates that physiological causes play a minor part in the decrease of the birth-rate. ”

“ After the act of procreation, the sexual passion in both subsides, and the reproductive function is not again called into exercise until after the intervening weeks or months of repose have passed and nature again responds to the necessity of procreation for the purpose of perpetuating the species. Where the periods of ovulation and fecundity recur at brief intervals in the female, the reproductive nature of the male is in a more continuous state of activity, so that a fruitful union may be secured when the reproductive nature of the female is in readiness ”

“ For as the pullet, engendered of an egg, is indebted to that egg for his body, vitality, and principal or generative part, so and in like manner does the egg receive all that is in it from the female, the female in her turn being dependent on the male for her fecundity which is conferred in coition.
And here we have an opportunity of inquiring, whether the male be the first and principal cause of the generation of the offspring; or whether the male along with the female are the mediate and instrumental causes of nature itself, or of the first and supreme generator? ”

“ Spanned round with the rainbow, the jewelled gloom folded music upon silence, light upon darkness, fecundity upon death, as a seed folds leaf upon leaf and silence upon the root and the flower, hushing up the secret of all between its parts, the death out of which it fell, the life into which it has dropped, the immortality it involves, and the death it will embrace again. ”

“ His soul leapt up into the gloom, into possession, it reeled, it swooned with a great escape, it quivered in the womb, in the hush and the gloom of fecundity, like seed of procreation in ecstasy.
She too was overcome with wonder and awe. She followed him in his progress. Here, the twilight was the very essence of life, the coloured darkness was the embryo of all light, and the day. Here, the very first dawn was breaking, the very last sunset sinking, and the immemorial darkness, whereof life's day would blossom and fall away again, re-echoed peace and profound immemorial silence. ”

“ This life-form, thus started, grows according to the laws of its becoming more and more, until, at the expiration of a fixed period, which varies greatly in different animals, it becomes a complete young individual, of the nature and kind of its parents. The fertilization of the ovum in the female is called conception; its growing state is called gestation, and its birth, on becoming a separate being, is called parturition. In its growing condition, and before its birth, the new young life form is known as the foetus. ”

“ As has already been said, this use of the sex organs, merely to produce progeny, and so insure a continuance of the race, is a quality that mankind shares with all the rest of the animal kingdom. In all essentials, so far as the material parts of the act are concerned, the beginnings of the new life in the human family differ not a whit from that of any other mammals. In each case the ovum is produced by the ovaries of the female, passes into the womb, is there met by the semen from the male, fertilized by the spermatozoa, and so the foetus gets its start. ”

“ This process is brought about, as we all know, by the sexual intercourse of the two sexes, and is called the act of impregnation. The result of this act on the part of the male and female is, that the formation of a new being is set up in the ovule or egg; this ovule or egg soon begins to be divided and subdivided, and to be fashioned into various complex organs, and eventually to develop into the form of one of its parents, as I explained in the first lecture. These are the processes by which the perpetuation of organic beings is secured. ”

“ The number of the offspring is greatly reduced. The ovum of the female and the sperm of the male become microscopic. The germ of life remains within the body of the mother until it has reached that stage of development which fits it for its independent life in the outer world. The pe [Pg 80] riod from conception to birth is greatly prolonged, and the periods of deliverance from the necessity of the reproductive act are alike extended. The higher in the scale the more dependent the offspring, until in the instance of man the offspring is the most helpless and dependent of all. ”

“ Marvelous are all the manifestations of the reproductive necessity. Considering that reproduction was at first merely a form of growth, a discontinuous kind of growth, that seized upon sex as a splendid means to escape death, the chemical methods evolved arouse a sense of awe. A baby is born with her or his glands practically as fixed for her or him as the color of the eyes. Thymus and pineal keep him a child, keep him unsexed. Then at puberty, a new current is added to the calmly flowing river, and behold! ”

“ But what determines the end of the pregnancy? Is it merely the increasing distension of the uterus by the developing foetus? This could scarcely be the case in the Marsupials in which the foetus when born is quite minute. Nor can we attribute parturition to renewed ovulation, for this occurs in Dasyurus only once a year. All we can suggest at present is that a certain periodic development takes place by heredity in presence of the hormones exuded by the fertilised ovum and the embryo developed from it. ”

“ At a later period, indeed, when the embryo is larger, when the ovum or conception has contracted adhesions with the uterus, and the umbilical vessels have penetrated the caruncles, the chorion extends further, and at its extremities on either side, and as it were in a couple of appendices, there is a certain fluid of a yellow colour, which you might call excrementitious, kept separate and distinct.
The human conception scarcely differs in any respect from an egg during the first months of pregnancy. ”

“ Young women of mature years should be made familiar with the physiological conditions which attend conception and maternity, and they need to know that from the [Pg 172] moment of conception life exists in the embryo, and that from the moment the spermatozoön enters and assimilates with the ovum a separate individual life is really begun, and that she is, at that very moment, the mother of this life within her as truly as when, in the later months, she feels the quickening within her, or after its birth experiences the joy of a mother who clasps her newborn infant in her arms. ”

“ The present belief regarding the causation of sex is that although there is but one kind of ovum, there are two kinds of spermatozoa, one capable of producing a male and the other a female child, but the sex-determining form of the male cell that fertilizes any one ovum is a matter of the merest chance. Statistics show that more male than female babies are born, the usual proportion being about 105 boys to 100 girls among those who are carried to “term” or the end of pregnancy. ”

“ In a given mating, we must take into consideration such factors as impediments to coitus, as well as those numerous agencies in the female which may interfere with the union of sperm and ovum, or with the successful implantation of the fertilized egg in the uterus, and its growth and development there till normal parturition takes place. Successful reproduction depends upon the mating of sexually sound females to equally sound males. ”

“ They prove that the embryo, called into existence by the mysterious act of fecondation (the only point that is mysterious about the process of generation according to Cuvier) may, and will, and does live independently of the mother,—with a life wholly its own, and that it derives from its parent growth only, or accretion of substance, as I stated in my preliminary observations. The museum of the Royal College of Surgeons supplies a most striking illustration, and I may add, corroboration of this opinion. ”

“ The stimulus of the sperm so pent up causes that ovary to mature a germ, although it may do so slowly, and after two or three months it is perfected, fertilized, and a second conception occurs within the uterus. If each embryo observe a regular period of growth and each be born at maturity, there must be an interval of two or three months between their births. But it is far more common for the parturition of the first, displaying signs of full maturity, to coincide with the birth of a second which is immature and which cannot sustain respiratory life. ”

“ The comparative growth of the fœtus infinitely surpasses that of its whole future existence. But the exact age of uterine embryos, and of abortives, is, in some degree, conjectural. Before the seventeenth day after conception, its rudiments are not even visible to the naked eye: the glary ovum has then slidden down from the ovarium, through one of the lateral tubes into the womb. The size of an abortion, comprehending the fœtus, its membranes, waters, and placenta, at the end of six weeks, does not exceed in size that of a pigeon’s or hen’s, and in three months, a goose’s egg. ”

“ The influences in the personality of the father and of the mother, which during fertilization find expression in the qualitative constitution of the sperm and of the ovum, respectively, can thus bring about a resultant tendency, acting in one direction or the other with varying force. Thus, after fertilization, we have this resultant tendency toward the formation of a male or female embryo.
But, Düsing continues, at this time the sex is not definitely determined. The influence of the nutritive condition in which the fertilized ovum finds itself has yet to make itself felt. ”

“ The elaboration of both ovules and sperm in the same individual is wasteful of vital energy. The concentration of vital energy on one reproductive element secures that one product in a higher degree of perfection. Thus better sperm and better ovules combine to produce better ova and a stronger embryo. This is in accordance with the effect of differentiation of functions and organs of all kinds. 2. Again, in all cross-fertilization different individual characteristics are inherited by the common offspring. ”

“ In these cases the fœtus is found outside of the Womb, in the Tube, or the Ovary, or even in the Abdomen, among the intestines. Such an occurrence seems to render it almost certain that the ovum must have been fecundated in the Ovary, because we cannot well conceive, if it were not so, how it could reach the outside of the Womb. This difficulty is not, however, regarded as insuperable, by the advocates of the opposite theory. Possibly conception may occur in both ways.
There are many causes which prevent conception, or, in other words, which produce barrenness and [56] sterility. ”

“ Twins.—The human female usually matures but one ovum at each menstrual period, the two ovaries acting alternately. Occasionally two ova are matured at once. If fecundation occurs, the result will be a development of two embryos at the same time. In rare cases, three or even four ova are matured at once, and by fecundation produce a corresponding number of embryos. As many as five children have been born alive at one birth, but have not lived more than a few minutes. ”

“ 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. ”

“ Every individual among the higher animals, whether male or female, begins as an impregnated ovum in the mother's body. Any such ovum contains elements of constitution from both of its parents. In the earliest existence of this impregnated ovum, there is a season of sexual indifference, or indecision, in which the embryo is both male and female, having the characteristic rudiments of each sex, only indifferently manifested. ”

“ Physiology of women.
With regard to the physiology of the female organs, the following topics should be considered: The meaning of puberty as the beginning of a long fertile period of about thirty years; the nature of menstruation as a periodical process preparing the lining of the uterus for reception and attachment of an embryo if a sperm-cell meets a liberated egg-cell near an ovary, and not as a season of illness invented by the powers of [154] darkness; the possibility of fertilization following sexual relations at any time during the fertile life of a woman ”

“ It appears as if fertility depended on such a delicate adjustment of the male and female elements to each other, that, unless constantly kept up by the preservation of the most fertile individuals, sterility is always liable to arise. ”

“ In § 346 was pointed out the apparent connexion between high cerebral development and prolonged delay of sexual maturity; and in §§ 366, 367, the evidence went to show that where exceptional fertility exists there is sluggishness of mind, and that where there has been during education excessive expenditure in mental action, there frequently follows a complete or partial infertility. Hence the particular kind of further evolution which Man is hereafter to undergo, is one which, more than any other, may be expected to cause a decline in his power of reproduction. ”