CHAPTER XV.

THE CHANGES WHICH PRECEDE, ATTEND AND FOLLOW CONCEPTION AND CHILDBIRTH.

_Continued._

But while these changes have been taking place within the womb itself, and the decidua or thickened membrane has been forming about this developing germ of life, let us consider some of the changes which have taken place within the ovum itself. If observant when opening a hen's egg, the observer will notice that the yolk is covered by a very thin membrane which encloses and separates it from the other portion of the egg, and holds it in its rounded form. The membrane is exceedingly delicate, but sufficiently thick and strong to serve its intended purpose. Now, the human ovum or egg consists of a vitellus or yolk, which is covered by a similar membrane, known as the vitelline. When this ovum or egg has been fertilized or impregnated, remarkable changes take place. This vitellus or yolk undergoes a series of segmentation or dividings which are known as spontaneous segmentation. The single minute yolk divides itself into two smaller balls or segments. These again subdivide into four; these four subdivide into eight, the eight into sixteen, and so on, resulting in the rearrangement of the yolk into a finely divided granular mass. While this division is in process, the divided parts arrange themselves orderly about the inner surface of the vitelline or yolk membrane, with the minute microscopic spaces between filled with a transparent fluid. While these cells have been multiplying and become so abundant as to be flattened against the internal surface of the yolk membrane, they have developed into true animal cells. The edges of these cells, where they come in contact with each other, form a continuous organized membrane, which lies just within the yolk membrane. This membrane is called the blastodermic membrane.

This new membrane, formed within the sac which originally enclosed the yolk of the ovum, now divides or separates itself into two distinct layers, known as the outer and inner blastodermic membranes, also called epiblast and hypoblast. The egg at this stage of development presents the appearance of a small round sac, the walls of which consist of three layers, each succeeding layer lying immediately within and in contact with the other which encloses it. The outer one of the three is the primitive yolk sac, the second is the outer layer of the blastodermic membrane, and the third the inner layer, while the interior cavity of the egg is filled by the transparent fluid previously mentioned.

In order to understand the beginnings of life it is important to have a clear conception of these different sacs, for these two membranes lying within the yolk sac, and together known as the blastodermic membrane, and separately as the outer and inner layers of the blastodermic membrane, contain the anatomical elements from which the organized being with its fully-formed body is to grow. Indeed, it may be said that these two blastodermic membranes are the body of the embryo which is to develop into the fully-formed physical man.

The noting of this division into two separate layers is important, for the outer one develops into the skin, spinal cord, muscles and bone, while from the inner layer is formed the intestinal canal and the organs of vegetative life.

Between these two blastodermic membranes other minute tissues are formed, the office and end of which are not so fully understood, and the consideration of which would lead us into intricacies beyond our present purpose.

The first visible sign of the organic structure of the human form is discovered as it takes shape upon the exterior wall of the blastodermic membrane, known as the embryonic spot, and known also as the primitive trace or furrow. It is supposed that from this is formed the spinal canal, with the dorsal plate upon either side, from which springs the framework of the bony structure, and at one end of which is the large rounded cavity which forms the receptacle for the brain and the medulla oblongata, or the upper cranial portion of the spinal cord, which is to control respiration, and at the other extremity of which, in a later stage, will sprout or grow the legs and feet.

Without complicating the subject too much for the clear understanding of the ordinary reader by undertaking to explain minute changes which are very interesting to specialists, but likely to detract from its interest and value to the ordinary reader, let it suffice to say that in the course of a brief period the embryo which has grown mainly from the two blastodermic membranes which we have described, and is attached to the walls of the womb by the placenta and cord which carries the blood and life-currents from the body of the mother to the growing body of the child within, is at this period of its development surrounded and enclosed by a number of membranes. The outer one of these is the inner lining of the womb itself, known as the decidua vera. Within this is the decidua reflex, the membrane of the womb, which extended itself and grew around the ovum, completely enclosing it. The third is the chorion, forming the outer membrane which encloses the fetus, and within which is the amnion, or innermost membrane which surrounds the fetus, and between which is another membrane, called the allantois.

The amnion, which is the innermost of the membranes surrounding the fetus, seemingly has a special office, which is to secrete the fluid technically called the amniotic. This fluid is popularly known as "the waters." This secretion performs several important offices. It protects the fetus from any local pressure or blow, and so distributes any pressure as to enable all the parts to grow without danger of distortion and deformity. It also affords the fetus greater freedom of motion, and protects the womb and other parts from injuries which might otherwise be inflicted by the fetus after quickening. Within this fluid the fetus floats during its formative period, and when the time of birth comes the breaking of the sac which contains this fluid enables it to flow out, lubricating the parts, or channel, through which the newly formed being is to pass in its exit into the outer world. The importance of this fluid in this latter office is of great moment. When the sac breaks and the waters flow away too much in advance of the birth of the child, there generally occur the inconveniences that attend what is called a "dry birth."

As already mentioned in a previous paragraph, during the first weeks of growth the embryo is nourished the same as the young chick within the egg, by the yolk, in which its earliest nourishment has been stored.

Soon the delicate union is formed between the chorion by the gathering and multiplication of the villi or minute hair-like membranes, which gather into a compact mass and adhere to the adjacent portion of the womb. This formation is known as the placenta, previously described, which is constituted of two portions--the maternal side, which is toward the walls of the womb, and the fetal side, which is toward the growing fetus. Upon the inner side, the placenta is united with the fetus by two arteries which are wrapped around the one vein, which together unite with the body of the placenta. Through these the life-currents flow; and, while the circulation between the bodies of mother and child are not direct or uninterrupted, for the fetus has its own measurably independent circulation, yet from the time the connection is formed until the cord is severed at birth the fetus derives all its nourishment from the mother.

Let us turn now to note the rapid changes which take place within the germ or egg from the time of its impregnation to the hour of the birth of the child. The changes, although seemingly very minute at first, are nevertheless very rapid from the beginning to the period of maturity and birth. The following account, taken from "Plain Talks on Avoided Subjects," by Henry N. Guernsey, M.D., constitutes a goodly portion of the introductory chapter of that excellent little book, and presents the matter in the intelligible and impressive manner we desire for this place, and is quoted in full by permission:

"The first indication of formation that is possible to discover, even by the help of the microscope, consists of an oblong figure, obtuse at one extremity, swollen in the middle, blunt-pointed at the other extremity. The rudimentary embryo is slightly curved forward, is of a grayish-white color, of a gelatinous consistence, from two to four lines long, and weighs one or two grains. A slight depression, representing the neck, enables us to distinguish the head; the body is marked by a swollen centre, but there are as yet no traces of the extremities. So much can be observed about the end of the third week after conception.

"At about the _fifth week_ the embryo presents more distinctions. The head is very large in proportion to the rest of the body, the eyes are represented by two black spots, and the upper extremities by small protuberances on the sides of the trunk. The embryo at this stage is nearly two-thirds of an inch in length and weighs about fifteen grains. The lower extremities now begin to appear in the shape of two minute rounded tubercles. Till about this time a straight artery has been observed to beat with the regularity of the pulse; but now it appears doubled somewhat into the shape of an adult heart, although as yet it has but one auricle and one ventricle. As time advances we find the perfect heart, with its two ventricles and two auricles, all developed from the original straight artery. At this period the lungs appear to exist in five or six different lobes, and we can barely distinguish the bronchial tubes; about the same time the ears and face are distinctly outlined, and after awhile the nose is also faintly and imperfectly perceived.

"At about the _seventh week_, little bony deposit is found in the lower jaw. The kidneys now begin to be formed, and a little later the genital organs. The embryo averages one inch in length.

"At _two months_ the rudiments of the extremities become more prominent. The forearm and hand can be distinguished, but not the arm above the elbow; the hand is larger than the forearm, but is not supplied with fingers. The sex cannot yet be determined. The length of the embryo is from one inch and a half to two inches, and it weighs from three to five drachms. The eyes are discernible, but still uncovered by the rudimentary lids. The nose forms an obtuse eminence, the nostrils are rounded and separated, the mouth is gaping, and the epidermis can be distinguished from the true skin.

"At _ten weeks_ the embryo is from one and a half to two and a half inches long, and its weight is from one ounce to an ounce and a half; the eyelids are more developed, and descend in front of the eyes; the mouth begins to be closed by the development of the lips. The walls of the chest are more completely formed, so that it is no longer possible to see the movements of the heart. The fingers become distinct, and the toes appear as small projections webbed together like a frog's foot. At about this period the sexual organs show their development, as follows: On each side of the urinary locality an oblong fold becomes distinguishable; in course of progress, if these folds remain separate, a little tubercle forms in the anterior commissure which becomes the clitoris; the nymphA| develop, the urethra forms between them, and the female sex is determined. If, on the other hand, these folds unite into a rounded projection, the scrotum is formed, the little tubercle above becomes the penis, and hence the male sex. The testicles forming within the body descend later into the scrotum, and organs similar to them, their counterparts, form in the females and are called ovaries. These ovaries are found attached to an organ called the womb, and this, again, is united with the vagina, which leads downwards and outwards between the labia majora (or larger lips).

"At the end of the _third month_ the weight of the embryo is from three to four ounces and its length from four to five inches; the eyeballs are seen through the lids, the pupils of the eyes are discernible, the forehead, nose and lips can be clearly distinguished. The finger-nails resemble thin membranous plates, the skin shows more firmness, but is still rosy-hued, thin and transparent. The sex can now be fully determined.

"At the end of the _fourth month_ the product of conception is no longer called an embryo, but a fetus. The body is from six to eight inches in length, and weighs six or seven ounces. A few little white hairs are seen scattered over the scalp. The development of the face is still imperfect. The eyes are now closed by their lids, the nostrils are well-formed, the mouth is shut in by the lips, and the sex is still more sharply defined. The tongue may be observed far back in the mouth, and the lower part of the face is rounded off by what a little later will be a well-formed chin. The movements of the fetus are by this time plainly felt by the mother, and if born at this time it may live several months.

"At the end of the _fifth month_ the body of the fetus is from seven to nine inches long, and weighs from eight to eleven ounces. The skin has a fairer appearance and more consistence; the eyes can no longer be distinguished through the lids, owing to the increased thickness of the latter. The head, heart and kidneys are large and well-developed.

"At the end of the _sixth month_ the fetus is from eleven to twelve and a half inches in length, and weighs about sixteen ounces, more or less. The hair upon the scalp is thicker and longer, the eyes remain closed, and very delicate hairs may be seen upon the margins of the eyelids and upon the eyebrows. The nails are solid, the scrotum small and empty, the surface of the skin appears wrinkled, but the dermis may be distinguished from the epidermis. The liver is large and red, and the gall-bladder contains fluid.

"At the end of the _seventh month_ the length of the fetus is from twelve and a half to fourteen inches; its weight is about fifty-five ounces, and it is both well-defined and well-proportioned in all its parts. The bones of the cranium, hitherto quite flat, now appear a little arched, and, as the process of ossification goes on, the arching increases until the vault is quite complete. The brain presents greater firmness, and the eyelids are opened. The skin is much firmer, and red. The gall-bladder contains bile.

"At the end of the _eighth month_ the fetus seems to thicken up rather than to increase in length, since it is only from sixteen to eighteen inches long, while its weight increases from four to five pounds. The skin is red, and characterized at this period by a fine downy covering, over which is spread a quantity of thick viscous matter, called the sebaceous coat, which has been forming since the latter part of the fifth month. The lower jaw has now become as long as the upper one, and in the male the left testicle may be found in the scrotum. Convolutions appear in the brain structure.

"At _nine months_ the anxious time of parturition (or birth) has arrived. The fetus is from nineteen to twenty-three inches in length, and weighs on an average from six to eight pounds. Children at birth sometimes weigh as much as fourteen pounds; but such extremes are very rare. At this period the white and gray matter of the brain are distinct, and the convolutions are well marked; the nails assume a horny consistence, hair upon the head is more or less abundant, the testes are in the scrotum, and the entire external genital organs of both male and female are well formed.

"How wonderfully and how instructively are all organs in the animal body disposed and arranged! In the highest place we find the brain to govern and rule over all below. It is the first organ formed, and in an orderly life should control all the others. Next in order and importance are the heart and lungs, which put into motion all other parts and enable the animal frame to continue in motion. So each and every organ is developed in its proper order, all to obey the commands of the first and most important--the brain, the seat of the reason and the will. Happy are they of either sex who will govern themselves by a pure, enlightened reason and a pure, affectionate will."

While we may note the various stages of change and progress, yet to the thoughtful student there lies back of all these outer manifestations a hidden life, a divine unfolding of the human body which is mysterious and awe-inspiring. While we know something of what takes place, yet the declaration of the Book of Ecclesiastes is impressively true: "Thou knowest not what is the way of the Spirit, nor how the bones do grow in the womb of her that is with child." All who study it thoughtfully and reverently can exclaim with David: "I am fearfully and wonderfully made: marvelous are Thy works; and that my soul knoweth right well. My substance was not hid from Thee, when I was made in secret, and curiously wrought in the lowest parts of the earth. Thine eyes did see my substance, yet being imperfect; and in Thy book all my members were written, which in continuance were fashioned, when as yet there was none of them."

Let us turn now to the mother who has nourished and who is about to bring into the world the body of an immortal being. Some of the changes most easily noted in the body of the mother occur as she reaches the period when approaching maturity has prepared the body of the child for an early entrance into the outer world. Marvelous as are the less noticeable changes which have earlier taken place, the time has now come when others which are more marked are soon to manifest themselves. Several days prior to the event there is a dropping or subsidence of the womb. This is preparatory to the distention and enlargement of the vagina through which the exit is to be made. The stomach and lungs are relieved of pressure, the mother feels more easy, is more inclined to move about, breathes more freely, and the sense of oppression which formerly caused her to desire inaction passes away, and Providence thus fits her to make such necessary preparations as are important in view of the event which is soon to take place. As the days approach, the external parts give indication of the distention and enlargement which has taken place in the vagina and the preparations which nature is making for the more easy exit of the life which has developed within.

The entire physical nature of the mother is in a state of preparation for the great event. A large quantity of blood is being sent to the breasts, the lacteals are developing, and the preparation is being completed for the secretion of milk, so that there may be no lack when the little stranger arrives.

One of the earliest indications that the event is about to take place is the discharge of the small plug of mucus which has served to hermetically seal the neck of the womb against the entrance of any foreign substance; but its office or work is now completed. The cervix, or neck of the womb, enlarges, and this little plug, popularly known as "the show," passes away with some streaks of blood. While the neck of the womb, the vaginal passage and the external parts have greatly enlarged, the womb itself is beginning to contract preparatory to the expulsion of that which it has fostered and nourished for a period of about nine months.

The earliest premonition that these contractions are taking place is found in the grinding pains, which come at irregular intervals, sometimes a couple of hours apart, or only separated by a half hour, or even a shorter period. These contractions of the abdominal muscles are soon followed by the true labor-pains, which come at more regular intervals. These grinding pains are felt in the back and loins. The contractions rise to a certain pitch of intensity, and then as gradually abate. Usually, as the regular labor-pains begin, the fluid contained in the amniotic sac, and within which the child has floated during its period of growth, is now liberated by the breaking of the sac, flows through the vaginal passage, lubricating the parts and preparing all for an easy exit of the body of the infant into the outer world. When the presentation is normal the head comes first, and usually in a period varying from a few minutes to a few hours the child is born. In exceptional cases the labor may be extended over a day or more, but such cases are relatively rare.

The apprehensions of dangers which associate themselves in the minds of many with childbirth are not often realized. If the parts are not diseased, and the mother is in good health, and the laws of the unfolding life have been carefully observed, there is little peril, although, generally, considerable pain. There are many physicians who have attended hundreds of women in confinement who have never lost but an exceptional case or two. The extreme pain endured by many women is largely due to the lack of that knowledge which would have enabled the mother to approach this period with but little apprehension, and to have passed through the period of parturition or childbirth with but slight inconvenience and pain.

While the perils may be greatly reduced and the pains greatly diminished, it is nevertheless a period of wonderful revolution throughout the entire physical nature of the mother. The blood which flowed from her heart to nourish and foster the growing body of her child is now turned in other directions, and the fountains at which the child is to receive its food and its strength begin to flow with their richness of life-giving currents.

After the placenta and the sacs which enclosed the fetus, which together constitute what is known as "the afterbirth," have passed away, the recuperating and renewing powers with which God has so wonderfully endowed the body of the mother beyond that of the father become active. The muscular tissues of the womb, vagina and the external parts at once begin to contract, and the entire nature of the mother begins to adjust itself to the new relations of her child to her own body and the necessities of nourishing and guarding it upon the external portion of her body, rather than within that mysterious chamber which God prepared for its beginning and the earliest unfoldings of its infant life.

When the child is born into the world its body also undergoes a wonderful revolution. Then, for the first time, its heart takes up its own independent action; air for the first time enters the cells of the lungs, and with the early shock, if it might so be called, of taking its first breath, the child usually utters its first cries. During the period of its fetal life the lungs have received only so much blood as was necessary for their own growth and development, but with the first breath they expand and receive the inflowing of the blood from the right side of the heart. This involves the opening of some passages and the closing of others. These are but the first of a series of transformations which are early to take place. The various veins, arteries and ducts which have hitherto received the supplies of blood from the placenta and returned the worn and wasted material to that same centre, or distribute the supplies for special service throughout different portions of the body, by the cutting of the umbilical or navel cord, and the separation of the child from the placenta and body of the mother, now assume a new relation to the independent body of the newborn child. Some of these ducts and arteries soon entirely close, and in some instances degenerate into impervious cords with new and important offices; some are transformed into true ligaments, while others remain pervious. Now that the primitive purposes of some of these parts have been fulfilled, the parts themselves disappear, while still other parts take upon themselves new offices and duties which are imposed by the changes incident to birth--the separation from the body of the mother and the entrance upon its own independent life in the outer world.

Truly, "we are fearfully and wonderfully made." The infinite Author of all things has left the stamp of His wisdom upon everything that He has created. Whether we take the microscope and study the earliest beginnings and mysterious unfoldings of this spark of human life; whether we study the blade of grass beneath our feet, or the stars that shine over our heads; everywhere we find the wonderful wisdom of our Creator. "Day unto day uttereth speech, and night unto night showeth knowledge." It matters not whether we listen to the lessons of a flower, the history of an atom, or the song of the spheres, "there is no speech nor language where their voice is not heard; their line is gone out through all the earth, and their words to the end of the world."