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."

What a Young Husband Ought to Know · 第 8 / 9 章