The principles of obstetrics; a practical manual for the student and general practitioner

Front matter

I

>01 i,V -ft,

V S

Preface

This manual has been prepared at the request of the publishers, who suggested that a concise, practical text-book upon the principles of obstetrics, written primarily from the standpoint of the student and at the same time covering the ground in such a manner as to be of value to the general practitioner, would be appreciated by the teachers and students of this country. The most conspicuous defect of the present text-books, of which there is no lack, upon this subject is their voluminous size, perhaps the only fault of several otherwise admirable manuals.

It has been the endeavor, therefore, to restrict this work to the smallest limits compatible with clearness and completeness. Everything of the nature of discussion and theory has been omitted, the design being to present the essential facts in plain, simple form, in order that the undergraduate student may acquire the science more in the shape which it will assume when as a physician he puts it to practical use. It is hoped that the book, then, will possess the additional advantage of becoming a working handbook adapted to the requirements of private practice, where the refinements of hospital instrumentation and nursing are conspicuously absent. It designs to teach that aseptic midwifery is possible under the restrictions of the private home, with the simpler armamentarium of the obstetrical handbag.

The author gratefully acknowledges the assistance of Drs. James A. Spalding and Richard D. Small, of this city, in critical revision of the manuscript, and the generous co-operation of the publishers in its illustration and publication.

Portland, Maine, June, 1903

CHAPTER II. Disorders of Pregnane) 7 .76

Disorders of the Birth Canal, 76

Diseases of the Gravid Uterus, . . ■ . . , . .76

Cervical Diseases during Pregnancy, ...... 80

Diseases of the Vagina during Pregnancy, . . . . .81

CHAPTER III. Mouth, 83

The Stomach, 83

CONTENTS.

IX

Intestines,

Liver,

Diseases of the Urinary System

Diseases of the Respiratory System during Pregnancy Diseases of the Circulatory System during Pregnancy,

The Blood in Pregnancy,

Diseases of the Nervous System during Pregnancy,

Infectious Diseases during Pregnancy, .

Acute Infectious Diseases, .

Skin Diseases during Pregnancy, . . . .

PAGE

88 89 89 92 93 95 96

97 97 99

Abortion, .

Miscarriage, Premature Labor

CHAPTER I. The Factors Concerned 127

III. The Passengers, . . . . . . . , .131

Diameters of the Fetal Head and their Approximate Average

Diagnosis of Presentation and Position by Abdominal and Vaginal Examination, . . . . .''"•'. . . . . 140

Vaginal Signs of the Different Presentations, .... 142

Chapter I. Anatomy Of The Obstetric Pelvis

Obstetrics is that department of medicine which relates to midwifery. Its design is the guidance of woman and her children during pregnancy, delivery, and the puerperium, the foundation of its practice being an intimate knowledge of the hard and soft parts of the birth canal. The anatomy of the pelvis and sexual organs will be therefore first presented, as briefly as the character of the subject permits.

THE OBSTETRIC PELVIS.

The obstetric pelvis is the bony girdle or incomplete basin at the lower end of the body, containing the female sexual organs, and through which the product of conception passes. The student will find a dried pelvis of great assistance while committing its details to memory.

The female pelvis differs from the male in being lighter and more shallow, the angle of the pubic arch is straighter, the end of the coccyx shorter, and most of its projections are less developed. In obstetrics it is never considered as a basin, but a canal, and only those details of its structure which are applicable to the specific purpose need to be mentioned.

It is constructed of four bones — sacrum, coccyx, and right and left innominate bones, the first two forming one-third, and remainder the other two-thirds, of the bony canal.

In the obstetric sense the promontory of the sacrum means the angle formed by the structures included in the sacro-lumbar articulation : the base of the sacrum, lower surface of the last lumbar vertebra, and cartilage between them. The cavity of the pelvis at this part is heart-shaped, because the promontory juts into it, resulting, when beyond a certain limit, in a special class of pelvic deformities. The sacro-iliac synchondrosis is the articulation of each wing of the sacrum with the opposing surface of the innomi-

FlG. i.— Articulated Female Pelvis ; Anterior Surface.

nate. The curve of the sacrum is its smooth inner surface, which varies in every pelvis, from a sharp bend in one to a nearly straight line in another.

The coccyx is the end of the spine, and articulates with the sacrum by the sacro-coccygeal joint. After middle life its motion is restricted by ossification,, making the two bones practically one, thus causing difficult labor.

The innominate has few details of obstetric importance. On its inner surface is an irregular curving ridge, linea ilio-pectinea, or ilio-pectineal line, which extends from the sacro-iliac synchondrosis downward and forward to meet its fellow of the opposite side. It is an important obstetric landmark, since it divides the true pelvis from the false and is a base-line for measuring the internal pelvic

AXAT01IY OF THE OBSTETRIC PELVIS.

diameters. Upon its crest are the anterior and posterior spinous processes, which offer points for obtaining the external pelvic diameters. Each innominate unites in front with its fellow by the symphysis pubis, the space between the rami of the ischia and the pubes being the arch of the pubis. The obturator foramen, between the ischium and pubis, is smaller and more nearly triangular in the female than the male, and in life is filled with the obturator membrane. On the lower edge of the innominate are the

Fig.

-Articulated Female Pelvis ; False Pelvis and Superior Strait.

tuberosity and spine of the ischium and the greater and lesser sciatic notches, to which important structures are attached.

The ilio-pectineal line divides the pelvis into two sections. Of these, the upper or false pelvis, because its bony rim is incomplete in front, is of no especial obstetric importance. The lower section is the true or obstetrical pelvis, because it contains the sexual organs and forms the birth canal. The pectineal line and promontory of the sacrum mark its upper boundary, variously called the brim, inlet, or superior strait. "The dried bony pelvis without its muscles is a basin without a bottom. The opening where the bottom ought to be is the outlet or inferior strait " (King).

The internal shape of the true pelvis is of great importance in the natural performance of childbirth, there being a standard type with individual variations. It is not a symmetrical bony cylinder, but a canal whose front wall is much cut away and the deficiency supplied by elastic tissues. This inequality in length of the walls bends the cavity forward, making its general direction crescentic, with a depth of an inch and one-half in front and five inches behind. At the apex of the heart-shaped brim is the symphysis pubis, on the sides the pectineal lines, and opposite the symphysis the promontory of the sacrum. In the recesses on each side of the latter are sheltered important blood-vessels and nerve

Fig. 3.— Articulated Female Pelvis ; Inferior Strait and Outlet.

trunks, the left having in addition the rectum. Projecting into the outlet are the spines of the ischia, from which pass upward two low ridges that partition off the side of the canal into two shallow surfaces, the anterior and posterior inclined planes of the pelvis. The posterior is imperfect in the dried pelvis, but completed during life by ligaments and muscles which cover and pass through the sacro-sciatic foramina. These planes are the chief factors in causing the head to rotate forward or backward during labor,

ANATOMY OF THE OBSTETRIC PELVIS. 7

If pieces of cardboard were fitted across the pelvic canal, their surfaces would represent what is meant by the planes of the pelvis, which are imaginary transverse sections of it at any given level. The axis of any plane is an imaginary line passing at right angles through it, and indicates the degree of its inclination to the body and horizon. For instance, when a woman is standing the plane of the brim tilts at an angle of about sixty degrees with the horizon, and its axis would be represented by a line passing from the umbilicus to the coccyx. While any number of these planes could be supposed, only three are needed for obstetrical purposes, the brim, middle, and outlet, and by taking the diameters of any given plane the dimensions of the canal at that point are obtained.

If the axes of a number of pelvic planes were united from above downward, an irregular curving line would result and be the axis of the pelvis, or the so-called " curve of Cams." The true direction of the pelvic canal follows the curve of the sacrum, which varies greatly in different women, as has been said. "The direction of the pelvis may be described with approximate accuracy as a line parallel with the sacral curve, and equally distant at all points from the pelvic walls " (Hirst).

The size of the birth canal depends upon race, heredity, habits of early life, and disease, with also individual differences. It is important to know the typical diameters of the pelvic planes in order to judge of the capacity of the canal for the passage of the child. While the size of the pelvic interior only is essential, the diameters of the exterior also assist in arriving at a conclusion. As it is impossible to measure accurately the living pelvis, special diameters of the dried pelvis are accepted as standards, and allowance is made for the soft parts in the living subject. The measurements given by different writers vary according as they are taken to the fractions of an inch, but such precision is generally useless and in actual practice impossible except for the expert. The present measurements are those of the average living Caucasian woman, and are approximate only.

Internal Diameter at the Brim. — i. The anteroposterior (diameter conjugata vera, C. V., sacro-pubic, true conjugate), from centre of the promontory of the sacrum to the top of the symphysis pubis, 4 inches (10.1 cm.).

s

THE PRINCIPLES OF OBSTETRICS.

2. The transverse (diameter transversa, T.), from side to side of the widest part, 4 inches (10.1 cm.).

3. The first oblique (diameter diagonalis dextra, D. D.), from right sacro-iliac synchondrosis to left pectineal eminence, 4^ to 5 inches (1 1.4 to 127 cm.).

4. The second oblique (diameter diagonalis laeve, D. L.), from left sacro-iliac synchondrosis to right pectineal eminence, 4^ to 5 inches (1 1.4 to 12.7 cm.).

At the Outlet. — 1. The antero-posterior (coccy -pubic, conjugate), from tip of the coccyx to lower end of the symphysis pubis, 4j4 to 5 inches (11.4 to 127 cm.).

2. The transverse (bisischiatic), from one tuberosity of the ischium to the other, 4 inches (10.1 cm.).

In the Cavity. — 1. The antero-posterior, from the centre of the symphysis pubis to the centre of the hollow of the sacrum, 5 inches (127 cm.).

2. The transverse, at the same level as the antero-posterior, 5 inches (127 cm.).

" The oblique diameters of the cavity and outlet are of little importance since their posterior extremities do not rest on fixed points " (Jewett).

ANTERO-POSTERIOR, •

c. V.

Oblique, D.

Transverse, T.

Inches.

Centimetres.

Inches.

Centime Lres.

Inches.

Centimetres.

Brim

10. 1

11.4-12.7

12.7

4^-5

4 4 5

Outlet

Cavity

External Diameters. — The external diameters of the pelvis vary somewhat according to the thickness of the overlying tissues, but have a general relation to the internal diameters, and are of the following average length :

The external conjugate (diameter of Baudelocque), from the dimple just below the last lumbar vertebra to a point half an inch below the upper edge of the symphysis pubis, y}4 inches (19 cm.). In life three and one-half inches must be taken from this to allow

AXATOMY OF THE OBSTETRIC PELVIS.

The sacro-iliac synchondrosis is the articulation between the sacrum and ilia, strengthened on both sides by firm ligaments. The posterior of these are the most important, since they act as slings in suspending the sacrum between other portions of the pelvis.

The coccyx is united to the sacrum by a hinge joint, sacro-

FlG.

-Muscles of the Female Perineum. (Testut.)

coccygeal, which is also reinforced by ligaments and in the adult has synovial membranes.

The symphysis pubis is the articulation between the front ends of the pubes, supplied with plates of cartilage, thicker in front than behind, synovial membrane, and strong internal and external ligaments. Below it the subpubic ligament forms the upper boundary of the pubic arch, and the triangular ligament braces the sides also of the arch together.

The lumbo-sacral articulation, between the last lumbar verte-

TILE PRINCIPLES OF OBSTETRICS, bra and sacrum, has a peculiar wedge-shaped cartilage placed with its base in front, a construction which not only helps in forming

Fig. 6.— Relation of Pelvis to Trunk (back).

the promontory but also tilts the sacrum backward upon the spinal column.

Chapter II. Female Sexual Organs

The female sexual organs and structures are classified into two groups, external or copulative, which are principally concerned in the act of impregnation, and internal or formative, within which the product of conception is developed and from which it is born.

EXTERNAL SEXUAL ORGANS.

The female external sexual organs and structures are the mons veneris, labia majora, labia minora, vestibule, and clitoris; they are called also the external genitalia, or pudendum, and, with the exception of the mons veneris, the vulva.

The mons veneris (mont de Venus) is a cushion of fat and fibrous tissue in front of the pubes, separated above by a furrow from the lower portion of the abdomen, and continuous below with each labium majus. It contains many sebaceous and sweat glands, and after puberty is covered with hair.

The labia majora (greater lips) are two long folds extending downward from the mons to surround the vaginal opening, and uniting in front at the anterior commissure. Each labium decreases in size as it passes downward, combining with its mate at the posterior commissure, or merging into the tissues in front of the anterior edge of the perineum. When the vaginal orifice is put upon the stretch, there appears within it in the virgin a crescentic fold of delicate skin, the fourchette, and between it and the posterior commissure is a slight depression, the fossa navicularis. The space between the anus and posterior commissure is the obstetrical perineum, the external surface being integument covered with hair, the internal mucous membrane, and between these are-

THE PRINCIPLES OF OBSTETRICS.

olar tissue, fat, and involuntary muscular fibre. The round ligaments extend from the uterus through the inguinal canal and are lost in the labia majora; the latter are analogous to the scrotum.

The labia minora (nymphae, lesser lips) are double folds of integument, which begin just below the anterior commissure, and

Fig. 7.— Female External Sexual Organs.

extend downward about an inch and one-half to the middle of the labia majora by which they are covered. Their inner surfaces are in contact when at rest. Each labium minus divides into two leaflets, the upper joining in front to form the prepuce of the clitoris, and the lower coalescing in front to form the frenum of the glans. The histological structure is intermediate between skin and mucous membrane, with luxurious vascular and nerve supply. The

FEMALE SEXUAL ORGANS.

surfaces of the nymphse are without fat, sweat glands, or hair, but have many sebaceous glands whose secretion prevents adhesion when the inner surfaces are in contact. The labia minora have individual differences in size and shape, being developed enormously in some races, particularly the Hottentot, and exceptionally in the Caucasian.

The clitoris is analogous to the penis and similar to it in structure, but without corpus spongiosum or urethra. It is about one inch long: and is situated in the middle line below the anterior commissure, where it is nearly concealed beneath the skin, the only part visible being the highly sensitive glans. The clitoris has two small erector muscles, the cavernous bodies being erectile like those of the penis, many blood-vessels and nerves, and is the chief organ of sexual feeling in women.

The vestibule is the triangular space bounded above by the clitoris, on the sides by the labia minora, and below by the vaginal opening. A little behind its centre is the meatus urethral or urinarius. Lying

along the sides of the vestibule and just within the nymphae, below the clitoris, are two oblong masses of veins, the bulbi vestibuli, about an inch in length, communicating freely with neighboring venous plexuses. They correspond to the corpus spongiosum of the male and during sexual excitement become swollen and erect.

The vulvo-vaginal glands (Bartholin's or Duverney's glands) are oblong bodies about one-third of an inch in diameter, situated on each side of the vaginal entrance and partly covered by the

Fig.

Vaginal Gland. (Testut.)

bulbs of the vestibule. Each discharges by a long slender duct, opening upon the inner side of the nymphae just outside of the vaginal entrance.

Vessels, Nerves, and Lymphatics of the External Sexual Organs.— The vascular supply of these structures is very abundant, and is derived from the internal pudic for the clitoris, superficial and deep external pudic for the labia, and superficial and transverse perineal for the perineum and adjacent parts.

The veins accompany the arteries and form large plexuses, emptying into the internal pudic. " The veins of these plexuses are remarkable for their large size, their frequent anastomoses, and the number of the valves which they contain " (Gray).

The lymphatics empty mainly into the superficial inguinal nodes.

The nerves are branches of the superficial perineal, inferior pudendal, and pelvic (inferior hypogastric) plexus of the sympathetic.

Chapter III. Internal Sexual Organs

The internal organs and structures are the uterus, the Fallopian tubes, and ovaries, including also the vagina and hymen which connect them with the external organs.

The hymen is a fold of mucous membrane partly closing the vagina, from which it is derived, and situated just posterior to the

Fig. 9.— Varieties of Hymen. (Testut )

fourchette. It is usually crescentic in shape with the concavity looking upward, sometimes circular or heart-shaped, and may be a septum with many small openings (cribriform), or entirely closed (imperforate). As the hymen may be absent from birth or destroyed by disease and gynecological examinations, its presence is no proof of virginity or its absence of unchastity. It is usually torn at the first sexual connection, but may persist to and delay delivery, the small projections remaining around the vaginal entrance after rupture being the carunculae myrtiformes. 2 17

The vagina extends from the vulva to the uterus in nearly a straight direction, generally parallel to the axis of the pelvis. It is tubular in shape, flattened from before backward, with the anterior and posterior surfaces naturally in contact, a cross section resembling the letter H. The lower extremity is contracted and surrounded by a band of muscular fibre, forming the sphincter vaginae. The upper extremity, enclosing the neck of the uterus, widens out into the vaginal vault or fornix, and the various portions are called, in accordance with their relations to the cervix, the anterior fornix, posterior fornix, and lateral fornices. The length in front is about two inches and a half, and behind from four to five inches, and after childbirth the canal never returns to its original diameter.

The walls are composed of three structures: externally a fibrous sheath, internally mucous membrane, and between these a double layer of muscles, the outer being longitudinal and the inner circular. Between the mucous membrane and the muscular coats is a layer of loose connective tissue filled with large veins and considered to be erectile. Extending along the inner surface of the mucous membrane is a central ridge, or raphe, from which delicate folds cross to each side of the canal, these corrugations providing for the extreme distention necessary during childbirth. The vagina is lined with squamous epithelia, numerous papillae, especially near the outlet, and is without glands except a few at the upper portion.

The vascular and nerve supply is very great, making it highly sensitive. The arteries are branches of the uterine, vaginal, vesical, and internal pudic. The veins accompany the arteries, having many plexuses continuous with those of the vulva, clitoris, and uterus, ending in the hypogastrics, but are without valves. The vaginal plexus of nerves arises from the lower part of the pelvic plexus.

The female urethra, though not a sexual organ, is of obstetric importance, and therefore is described with the vagina. It is a very distensible canal, about an inch and one-half long, and naturally about one-half in diameter, beginning at the meatus, passing backward and slightly upward, and ending at the neck of the bladder. The calibre is much larger than is that of the male urethra, being

INTERNAL SEXUAL ORGANS.

smallest at the entrance and dilating toward the bladder ; its walls are formed of three coats : muscular, erectile, and mucous membrane. Throughout the latter are many tubular glands, two of which, larger than the rest and opening upon the floor of the urethra on each side of the meatus, are named, from their dis-

FlG.

-Sagittal Section of the Lower Part of a Female Trunk, Right Segment. (Testut.)

coverer, Skene's glands. The meatus urethrse, or urinarius, is a small prominence with a vertical slit near the posterior border of the vestibule.

The uterus is the organ of gestation, shaped like a pear, with its base upward and long axis slightly curved forward. Its average external length in the virgin is three inches, its width one inch and a half, its thickness an inch, and its weight one ounce ; but

THE PPIMIPLES OF OBSTETRICS.

all these dimensions are increased after childbirth and decreased after the menopause.

It is situated near the outlet of the pelvis, with the vagina below, the bladder in front, the rectum behind, and the small intestines resting upon it above.

This position is not a fixed one, but varies at different times and within certain limits. A distended bladder pushes the uterus backward, a full rectum displaces it forward, and with every act of respiration it rises and sinks in the pelvis ; but ordinarily the uterine axis is at right angles to that of the vagina.

The uterus is divided, anatomically, into body and neck ; the first is subdivided into the fundus, the broad extremity above the Fallopian tubes, middle portion, which tapers downward to the isthmus, merging into the neck, or cervix, whose outlet divides transversely into two lips, the posterior being the longer.

The organ is formed of three coats: external, middle, and inner.

The external or serous is derived from the peritoneum, which envelops it like the curtains of a tent, covering the whole posterior surface downward to an inch below the junction of the cervix and vagina, but anteriorly only its upper two-thirds. The middle or muscular coat forms the mass of the uterus, the muscles being arranged in three layers, which in the unimpregnated organ cannot be separated. A thin external layer is continuous with the muscular fibres of the Fallopian tubes. The middle or principal stratum is disposed in longitudinal, circular, and spiral directions, and a delicate inner lining surrounds the opening of the Fallopian tubes, forming also a sphincter about the internal and external os. The neck or cervix is made up largely of connective tissue with a band of circular fibres at the vaginal junction.

Fig.

— Relation of Peritoneum to Uterus. (Schaefer.)

INTERNAL SEXUAL ORGANS.

During pregnancy all these muscles with their vessels and nerves are enormously developed.

The cavity of the uterus is divided into two unequal portions, body and neck. The upper, or body, is triangular in shape, each angle forming the cornu in which are the openings of the Fallopian tube; the inner surfaces are in contact and are furnished with three orifices, one for each Fallopian tube and one for the internal os, the latter separating the upper cavity from the lower, or cervix.

TUBAL VESSELS

ANASTOMOSIS OF

UTERINE AND

OVARIAN ARTERIES

FALLOPIAN TUBE

VAGINAL VENOUS PLEXUS

UTERINE ARTERY

SUPERIOR VAGINAL ARTERIES

OS UTERI VAGINA CUT OPEN BEHIND

FlG. i2.— Vessels of the Uterus and its Appendages (rear view). (Testut.)

This portion is slightly flattened and oval, its lower opening being the external os, or os tincae.

The third coat is mucous membrane and lines the whole interior of the cavity. It is about one-twenty-fifth of an inch thick at the fundus, but is much deeper in the central portion, being covered in the natural condition with columnar ciliated epithelia, and penetrated by numerous tubular glands, arranged at right angles to the surface and lined with ciliated epithelia. The mucous membrane of the cervix is denser than that of the body, is covered with both ciliated and squamous epithelia, and is disposed on the anterior and posterior surface in ridges, called arbor vitae, or palmae plicatae, which during gestation are obliterated.

Ligaments of the Uterus. — The uterus is suspended in the pelvis by three pairs of ligaments: the broad or lateral, one on each side, formed by two wide folds of peritoneum, which, after covering the uterus anteriorly and posteriorly as has been described, unite at its sides, and after enveloping the Fallopian tubes and other structures pass to the lateral walls of the pelvic brim ; the utero-sacral (post-uterine, folds of Douglas), composed of two folds of peritoneum passing from the back and upper portion of the vagina to the posterior pelvis, enclosing at its deepest part a space called Douglas' cul de sac; and round, partly serous and partly muscular, extending from each upper angle of the uterus through the inner abdominal ring and inguinal canal, to disappear in the mons veneris and labia majora.

Vessels and Nerves of the Uterus. — The vascular and nervous supply is very great, corresponding in growth during pregnancy with that of other related structures. Its arteries are remarkable for their twisted course and frequent anastomoses, the chief supply being the uterine, a branch of the internal iliac, which joins the ovarian, derived from the aorta, at the fundus. It courses along the side of the uterus, anastomosing freely with corresponding vessels from the other side, the largest of which is the circular at the isthmus. The veins collect into many sinuses that unite laterally in the utero-vaginal plexus, the latter joining a mass of veins, called pampiniform plexus, near the ovary. The lymphatics are also numerous, ending in the inguinal and lumbar nodes. The nerves are chiefly from the sympathetic system.

Fallopian Tubes. — The Fallopian tube (oviduct, salpinx) is the canal between either ovary and the interior of the uterus. Each is from three to five inches long, extending from a cornu of the uterus along the upper edge of the broad ligament outward to the brim of the pelvis, thence inward to the free border of the ovary. At the uterine orifice the canal is very small, admitting only a bristle ; it dilates widely in the middle portion, or ampulla, and ends in a trumpet-shaped collection of projections, or fimbriae, the largest being attached to the ovary and the remainder floating in the peritoneal cavity into which they open. Each tube has three coats : the outer or serous, continuous with the peritoneum of the broad ligament ; the middle or muscular, derived from the uterus

IXTERXAL SEXUAL ORGANS.

and formed in two layers (the outer longitudinal, enclosing a circular) ; and the inner or mucous membrane, continuous with

Fig. 13.— Cross Section through Isthmus of Fallopian Tube during Pregnancy, illustrating the Folding of the Interior. (Microscopic.) (Schaeffer.)

that of the uterus, and arranged in many long folds (plicated), lined with ciliated epithelia propelling toward the uterus.

Ovaries. — The ovaries are the female reproductive organs, analogous to the testes in the male, and are two in number, each lying on the side of the uterus, a little below its fundus, in the posterior fold of the broad ligament, beneath the Fallopian tube. Their size varies with their functional activity, but ordinarily it is that of an almond, an inch and one-half long, three-quarters of an inch wide, one-half an inch in thickness, and weight one drachm. The posterior border is convex and free ; the anterior is straight and contains the hilum. In youth the external surface is smooth ; after puberty it is uneven from projecting Graafian follicles and scars resulting from their rupture ; in old age it is hard and pale. The ovary is covered with a layer of peritoneum supplied with columnar epithelia ; below this a thick coat of fibrous tissue, forming the tunica albuginea and enclosing the firm ovarian stroma, composed 1 of fibrous and muscular tissue traversed by numerous blood-vessels.. Within the stroma are many small vesicles, the Graafian follicles, in all stages of development.

THE PRINCIPLES OF OBSTETRICS.

The ovarian ligament extends from each angle of the uterus to the inner edge of the ovary. The arteries are the ovarian from the aorta at the hilum. The veins accompany the arteries and form near the ovary the pampiniform plexus. The nerves are from the pelvic (inferior hypogastric) plexus and ovarian plexus, and lymphatics are the same as those of the uterus.

Fig. 14.— Section of Ovary.

Mammary Glands. — The mammae, or breasts, while strictly not sexual organs, are usually associated with them in description. These are glandular structures belonging to both sexes, remaining undeveloped, with possible exceptions, during the life of the male. In the female they are associated in growth with the other sexual organs at puberty, are functionally active after childbirth, and atrophy in old age. They are usually two in number, situated on the sides of the thorax between the third and fifth ribs, with personal differences in size, but either or both may