Читать книгу Woman - William J. Robinson - Страница 33

Fecundation or Fertilization—Process of Fecundation—When the Ovum Matures—Fate of Ovum When no Intercourse Has Taken Place—Entrance of Spermatozoa as Result of Intercourse—The Spermatozoa in Search of the Ovum—Rapidity of Movements of Spermatozoa—Absorption of Spermatozoön by Ovum—Activity of Impregnated Ovum in Finding Place to Develop—Pregnancy in the Fallopian Tube and Its Dangers—Twin Pregnancy—Passivity of Ovum and Activity of Spermatozoön Foretell the Contrasting Rôles of the Man and the Woman Throughout Life.

Fecundation and fertilization are important terms to remember. They stand for the most important phenomenon in the living world. Without it there would be no plants and no animals, excepting a few very low forms of no importance, and of course no human beings.

Fecundation or fertilization is the process of union of the female germ cell with the male germ cell; speaking of animals, it is the process of union of the egg or ovum of the female with the spermatozoön of the male. When a successful union of these two cells takes place a new being is started. The process of fertilization or fecundation is also known as impregnation and conception. We say, to fertilize (chiefly, however, when speaking of plants) or to fecundate an ovum, or to impregnate a female or woman, and to conceive a child. We say the woman has become impregnated or has conceived.

The Process. The process of fecundation is briefly as follows. An ovum becomes mature, breaks through its Graafian follicle in the ovary and is set free. It is caught by the fimbriated or trumpet-shaped extremity of the Fallopian tube and, moved by the wave-like motion of the cilia[4] of the lining of the tube, it begins its travel towards the uterus. If no sexual intercourse has taken place nothing happens. The ovum dries up, or "dies," and either remains somewhere in the tube or womb or is removed from the latter with the menstruation, or mucous discharge. But if intercourse has taken place, thousands and thousands of the male germ cells or spermatozoa enter the uterus through its opening or external os, and begin to travel upward in search of the ovum. The spermatozoa are capable of independent motion, and they travel pretty fast. It is claimed that they can travel an inch in seven minutes, which is pretty fast when you take into consideration that a spermatozoön is only ⅓00 of an inch long. Many of the spermatozoa, weaker than the others, perish on the way, and only a few continue the journey up through the uterus to the tube. When near the little ovum, which remains passive, their movements become more and more rapid, they seem to be attracted to it as if by a magnet, and finally one spermatozoön—just one—the one that happens to be the strongest or the nearest, makes a mad rush at it with its head, perforates it, and is completely swallowed up by it. As soon as the spermatozoön has been absorbed by the ovum, the opening through which it got in becomes tightly sealed up—a coagulation takes place near it—so that no other spermatozoa can enter the ovum. For if two or more spermatozoa got into the same ovum a monstrosity would be apt to be the result.

Spermatozoön Penetrating the Ovum.

What becomes of all the other spermatozoa? They perish. Only one is needed. But in the ovum that has been impregnated, and which is now called an embryo, a feverish activity commences. First of all it looks for a fixed place of abode. If the ovum happened to be in the uterus when the spermatozoön met and entered it, it remains there. It becomes attached to some spot in the lining of the womb and there it grows and develops, until at the end of nine months it has reached its full growth, and the womb opens and it comes out into the outside world. If the ovum is in the Fallopian tube when the spermatozoön meets it, as is usually the case, it travels down to the uterus, and fixes itself there.

Extra-Uterine Pregnancy. The tube is a bad place for the ovum to grow and develop, because the tube cannot stretch to such an extent as the uterus can, nor can it furnish the embryo such good nourishment as the uterus can. Occasionally, however, it happens that the impregnated ovum remains in the tube and develops there; we then have a case of what we call extra-uterine (outside-of-the-uterus) or tubal pregnancy. Extra-uterine pregnancy is also called ectopic pregnancy, or ectopic gestation. Unless diagnosed early and operated upon, the woman may be in great danger, for after a few weeks or months the tube generally ruptures.

From the moment the spermatozoön has entered the ovum, a process of division or segmentation commences. The ovum, which consists of one cell, divides into two, the two into four, the four into eight, the eight into sixteen, these into thirty-two, these into sixty-four, 128, 256, 512, 1,024, until they can no longer be counted. This mulberry mass of cells arranges itself into two layers, with a cavity in between. And from these layers of cells there develop gradually all organs and tissues, until a fully formed and perfect child is the result. If two ova are impregnated at the same time by two spermatozoa, the result is twins.[5]

I might mention here that the moment the ovum is impregnated, i.e., joined by a spermatozoön, it is called technically a zygote; it is also called embryo, and this name is applied to it until the age of five or six weeks. Some use the term embryo up to two or three months. After that, until it is born, it is called fetus.

A study of the development of the embryo and the formation of the various organs from one single cell, the ovum, vitalized or fecundated by another single cell, the spermatozoön, is the most wonderful and most fascinating of all studies. But that belongs to the domain of Embryology, which is a separate science.

What we see in the process of fecundation is a foreshadowing of the future man and woman. The ovum has no motion of its own, it is moved along by the wave-like motions of the lining cells of the Fallopian tube, and throughout the entire act it remains passive. The spermatozoön, on the other hand, is in a state of continuous activity from the moment it has been ejaculated by the male until it has reached its goal—the ovum. And as the spermatozoa carry in them the entire impress of the man, and the ova of the woman, they foretell us the fates of the future boy and girl. The woman's rôle throughout life is a passive and the man's an active one. And in choosing a mate the man will always be the active factor or pursuer. So biology seems to tell us. Whether education—using the word in its broadest sense—will effect a radical change in the relation of man and woman remains to be seen. A change putting the man and the woman on a footing of equality would be desirable; but whether biological differences having their roots in the remotest antiquity can be obliterated, is a question the answer of which lies in the distant future. As Geddes and Thomson so well said: The differences [between the sexes] may be exaggerated or lessened, but to obliterate them it would be necessary to have all the evolution over again on a new basis. What was decided among the prehistoric Protozoa cannot be annulled by act of Parliament.