FEMALE ORGANS OF GENERATION.

The female organs of generation have been usually classed by the English authors under the two heads of internal and external; a similar arrangement has also been followed by the Continental writers, but with the advantage of using distinctive terms which are more expressive of their peculiar functions, viz. the formative and copulative organs. Under the first are included the ovaria, Fallopian tubes, and uterus: under the second, the vagina and external parts. We propose to give a short description of these in the unimpregnated state, and then to describe the changes which they present during pregnancy, labour, and the puerperal condition. In point of situation and arrangement they bear a considerable resemblance to the generative organs in the male, being situated at the lower portion of the trunk, and arranged in symmetrical order, so that they either occur in pairs, one on each side the median line of the body, or singly, being equally divided by it throughout their whole length. Although there is in many points considerable difference between the male and female organs, still there is sufficient resemblance to entitle them to be considered as being formed upon the same fundamental type, a resemblance which is seen still more strikingly in the early periods of foetal life. They differ essentially from all the other organs of the system, being in activity during a portion of a woman’s life only, and then only at intervals.

Ovaria. The ovaries are situated in the upper part of the cavity of the pelvis, one on each side, near to the uterus, to which they are merely attached by a ligament (the ligamentum ovarii) which is a portion of that duplicature of the peritoneum which connects the uterus to the pelvis, and is known by the name of ligamentum latum, or broad ligament.

They are of an oval figure; their anterior and posterior surface is convex, the superior margin is also convex, while their lower edge is straight or somewhat concave: towards their inner and outer extremities they become thinner.

Their external surface in the virgin state is usually smooth, but in advanced age they become uneven and shrivelled; when fully developed they are about an inch and a half in length: their greatest breadth, which is at that portion of the ovary which is farthest from the uterus, is half an inch; their thickness is somewhat less.

The ovaries are supplied with blood by the spermatic arteries, which are of course considerably shorter in the female; they pass between the two layers of the broad ligament to the ovarium, assuming there a beautifully convoluted arrangement, very similar to the convoluted arteries of the testis. These vessels traverse the ovary nearly in parallel lines, forming numerous minute twigs, which have an irregular knotty appearance from their tortuous condition, and appear to be chiefly distributed to the Graafian vesicles. The external covering of the ovaries is formed by peritoneum, which here receives the name of Inducium; it envelopes the parenchymatous tissue of the gland called stroma, which is a dense laminar cellular tissue of a reddish colour; its external portion which is in contact with and firmly adherent to the indusium, is condensed into a species of covering of a firm structure and whitish colour, and is called the tunica albuginea of the ovary. In the substance of the stroma are embedded a number of vesicles of various sizes, which, although previously described by Vesalius and Fallopius, have been called Graafian vesicles, after De Graaf. These do not commonly become visible until the seventh year, from which period they gradually enlarge until puberty, when the ovaries increase in size, become softer and more vascular, and one or two of these vesicles may be observed to be larger, more developed, and projecting considerably from the surface of the gland.

The proper capsule of the Graafian vesicle is composed of two layers. The outer is formed of dense cellular tissue, in which are ramified many blood vessels; the inner layer is thicker, softer, and more opaque than the preceding, to which it is closely united, and from which it receives vascular twigs.

Ovum. The contained part or nucleus of the vesicle of De Graaf consists of, first, a granulary membrane, enclosing, secondly, a coagulable granular fluid; thirdly, connected with the granulary membrane on one side is a circular mass or disc of granulary matter, in the centre of which is embedded, fourthly, the ovum.

This disc, called by Baer the proligerous disc, presents in its centre on the side towards the interior of the vesicle, a small rounded prominence, called the cumulus, and on the opposite side a small cup-like cavity hollowed out in the cumulus. The cavity is for the reception of the ovum.[1]

Diagram of a section of the Graafian Vesicle and its contents, showing the situation of the Ovum.

a The granulary membrane. b The proligerous disc. c Ovum. d The inner and outer walls of the Graafian vesicle. e Indusium of the ovary. From T. W. Jones.

From the very minute size of the human ovum, and the difficulty of detecting it, the existence of this little corpuscule was not satisfactorily ascertained until modern times. Although De Graaf had observed ova in the Fallopian tube so early as 1668, which fact had been confirmed by the researches of Dr. Haighton and Mr. Cruickshank, still, as no traces of such ova had been discovered in the Graafian vesicle, and as it was evident that the Graafian vesicle, from its size, &c. could not pass along the Fallopian tube, it was concluded that the inner surface of the vesicle was a species of glandular structure which secreted the fluid with which it was filled, and which was analogous to the semen of the male testicle; hence, in former times, the ovaries were known by the name of testes muliebres. The celebrated anatomist Steno[2] first pointed out the analogy between these organs and the ovaries of the fish tribe: this view was afterwards supported by De Graaf,[3] and they have since continued to retain the name of ovaries.

To Professor von Baer, now of St. Petersburg, is due the merit of having first pointed out the distance of the ovum in the Graafian vesicle, and of thus putting beyond all doubt the accuracy of De Graaf’s observations, as well as those of Dr. Haighton and Mr. Cruickshank.

Corpus luteum. Upon impregnation taking place, one or more of the most prominent Graafian vesicles begins to show marks of considerable vascularity, both in its external capsule and in the surrounding stroma of the ovary. The vesicle swells, and at length bursts, discharging its contents into the funnel-shaped extremity of the Fallopian tube, which firmly grasps the ovary at this point by means of its fimbriÆ.

These changes begin to take place immediately after impregnation; the inner lining of the vesicle, which Professor von Baer considers to be a mucous membrane, appears to undergo a rapid development, much more so than the external capsule which contains it. It is, therefore, thrown into a number of corrugations by which the cavity of the vesicle is greatly diminished; it becomes much thicker, and assumes a yellow colour. As its growth proceeds, the cavity of the vesicle becomes still farther contracted, until being unable longer to retain its contents, it bursts and discharges them as above described.

The remains of the ruptured vesicle form a round glandular yellow coloured body, called corpus luteum: it projects considerably from the surface of the ovary, attaining the size of a small mulberry. In the middle of this projection there is a little irregular and generally triangular depression or indentation, which is the opening through which the ovum was discharged from the Graafian vesicle: this after a short time closes, forming a little cicatrix on the surface of the ovary.

“Upon slitting the ovarium at this part, the corpus luteum appears a round body, of a very distinct nature from the rest of the ovarium. Sometimes it is oblong or oval, but more generally round. Its centre is white, with some degree of transparency; the rest of its substance has a yellowish cast, is very vascular, tender and friable, like glandular flesh. Its larger vessels cling round its circumference, and these send their smaller branches inwards through its substance: a few of these larger vessels are situated at the cicatrix or indentation on the outer surface of the ovarium, and are there so little covered as to give that part the appearance of being bloody when seen at a little distance.”[4] Upon making a section of a corpus luteum, we observe that its cavity has an angular form, from which, as from a centre, white lines radiate to the circumference of the vesicle; an appearance which is evidently produced by the corrugation of the inner membrane of the vesicle, as above alluded to. To a similar cause we may also attribute the lobular appearance, which the structure of the corpus luteum presents when a section is made of it. The number of these corpora lutea corresponds exactly with the number of newly formed ova. Meckel, after having examined no less than two hundred pregnant animals of the class mammalia, found that the number of corpora lutea corresponded exactly with that of the young produced. “When there is only one child,” says Dr. W. Hunter, “there is only one corpus luteum, and two in the case of twins. I have had opportunities of examining the ovaria with care in several cases of twins, and always found two corpora lutea. In some of these cases there were two distinct corpora lutea in one ovarium, in others there was a distinct corpus luteum in each ovarium.”

A Graafian vesicle cannot be converted into a corpus luteum except by actual and effective sexual intercourse; and the strange and discrepant accounts which have every now and then been published, even by authors of considerable repute, of corpora lutea having been found in the ovaries of virgin and even newly-born animals merely prove that the true characteristics of the corpus luteum were not sufficiently known. The irregular cysts, cavities, or deposites of whitish or yellowish structure which are frequently found in the ovary, independent of impregnation, and which have been improperly enough called virgin corpora lutea, present points of difference so marked that they can scarcely be mistaken by an experienced eye. The angular cavity opening externally, the stellated, radiated, cicatrix-like appearance, which a section of the corpus luteum presents, its soft and delicate structure as described by Dr. Hunter, and above all its vascularity, and the facility with which its vessels can be injected from the general tissue of the ovary, are characters only found in a true corpus luteum. Virgin corpora lutea frequently occur under circumstances of disease, especially those of a tubercular character. They frequently appear as distinct cysts, the walls of which are semi-cartilagenous; at other times they seem to be nothing more than a coagulum of blood: they seldom project much from the ovary, and in no instance have they the peculiar structure of the corpus luteum, nor the external cicatrix, nor are they capable of being injected.

After awhile the cavity of the corpus luteum contracts, and the opening into it closes. The surrounding stroma loses its vascularity, the prominence at this part of the ovary gradually subsides, and the ovary returns to its former size. The periods at which these changes take place vary, but with the exception of those first mentioned they proceed slowly whilst pregnancy lasts, after which time, now that the increased activity of the pelvic circulation peculiar to that period has ceased, they advance more rapidly.

“If an examination be made within the first three or four months after conception, we shall, I believe, always find the cavity still existing, and of such a size as to be capable of containing a grain of wheat at least, and very often of much greater dimensions: this cavity is surrounded by a strong white cyst (the inner coat of the Graafian vesicle,) and as gestation proceeds the opposite parts of this approximate, and at length close together, by which the cavity is completely obliterated, and in its place there remains an irregular white line, whose form is best expressed by calling it radiated or stelliform.”[5] Dr. Montgomery adds, “I am unable to state exactly at what period the central cavity disappears, or closes up to form the stellated line. I think I have invariably found it existing up to the end of the fourth month. I have one specimen in which it was closed in the fifth month, and another in which it was open in the sixth: later than this I never found it.”

When pregnancy is over, the corpus luteum gradually diminishes and disappears. Dr. Montgomery states that “the exact period of its total disappearance I am unable to state, but I have found it distinctly visible so late as at the end of five months after delivery at the full time, but not beyond this period.” Hence it will be seen that in a few months after the termination of pregnancy, all traces of the corpus luteum are lost, and that, therefore, it will be impossible to decide as to how frequently impregnation has taken place, merely by examining the ovaries, as has been supposed. There is also another point to which Dr. Montgomery has alluded, which is well worthy of notice: in mentioning the fact that a vesicle may contain two ova, and thus a woman be delivered of twins, and yet there be but one corpus luteum, he observes that “the presence of a corpus luteum does not prove that a woman has borne a child, although it would be a decided proof that she has been impregnated, and had conceived, because it is quite obvious that the ovum, after its vivification, may be, from a great variety of causes, blighted and destroyed, long before the foetus has acquired any distinct form. It may have been converted into a mole or hydatids: thus, however paradoxical it may at first sight appear, it is nevertheless obviously true, that a woman may conceive and yet not become truly with child, a fact already alluded to, as noticed by Harvey; but the converse will not hold good. I believe no one ever found a foetus in utero without a corpus luteum in the ovary; and that the truth of Haller’s carollary, ‘nullus unquam conceptus est absque corpore luteo’ remains undisputed.”

During childhood, the ovaries present a perfectly smooth surface, and their structure appears to be homogeneous, consisting of a dense cellular tissue. About the seventh year, the first traces of the Graafian vesicles make their appearance; as the period of puberty approaches, the whole gland enlarges, becomes softer and more vascular; the Graafian vesicles are more numerous, and generally one or two will be found larger and more prominent than the rest. After repeated impregnations, and especially towards that time of life when the catamenia are about to disappear, the ovary becomes more or less flabby and corrugated, and at a still more advanced age presents a shrivelled appearance.

The ovaries are liable to inflammation and its consequences, more especially abscess, general enlargement, and induration: the malignant changes of structure, viz. cephaloma, hÆmatoma, and cancer, rarely have their origin in the ovaries, but extend to these organs from the adjacent parts. Lipomatous or fatty tumours are occasionally met with, containing hair, rudiments of teeth, &c. Cysts not unfrequently occur in the ovaries, and attain a very considerable size; they are simple or compound, sometimes consisting of several cysts one within the other, and distended with fluids, which vary considerably in their character. These tumours come under the general head of Ovarian Dropsy. The ovaries are also liable to many remarkable morbid changes in the puerperal state, such as softening and complete disorganization, the natural structure of the organ being entirely broken down and converted into a bloody pulpy mass; in some cases the whole gland is apparently dissolved away, so as scarcely to leave a trace of its previous existence.

Fallopian tubes. The Fallopian tubes, which act as excretory ducts to the ovaries, take their course through the upper portion of the broad ligaments, running from without inwards, towards the superior margin of the uterus, the ovaries being situated behind and somewhat above them. They are somewhat contorted, and are considerably more dilated at their abdominal extremity where they are unattached, than where they are connected to the uterus, being as much as from three to four lines at the former point; whereas, at the latter, they are not more than half a line.

Their abdominal extremity, which is like the mouth of a funnel, has its edge strongly fimbriated, and has hence been called the morsus diaboli. Their other extremity opens into the cavity of the uterus at the angle which the fundus forms with its sides, and the whole of the tube is about five inches.

The Fallopian tubes receive their external covering from the peritoneum, which becomes connected at their open extremity with the membrane which lines them. Between the external and internal membrane is the proper tissue of the tubes, and which, except in very muscular subjects, seldom display the fibrous structure; still, nevertheless, two layers of fibres have been observed—an outer or longitudinal, and an inner or circular layer. The Fallopian tubes are lined with mucous membrane, forming numerous longitudinal rugÆ. The canal is not pervious during the early months of foetal life, the abdominal extremity being closed and rounded; this appears to open about the fourth month. The canal is relatively larger, the younger the embryo is, and may, therefore, be easily demonstrated at this time.

At the period of impregnation, the Fallopian tubes implant themselves by means of their fimbriated extremity upon that part of the ovary where the Graafian vesicle is about to burst; they become remarkably engorged with blood, assuming a deep purple colour, and are now much thicker; the canal enlarges, so that a tolerably-sized probe can be introduced, whereas, at other periods it will scarcely admit a large bristle. The uterine extremity of the tube is closed by a continuation of that pulpy coagulable lymph-like secretion which now lines the cavity of the uterus, forming the membrana decidua of Hunter, and which, especially on the side where the corpus luteum is found, extends into the tube to nearly the distance of an inch. The tubes are now observed to be in a state of distinct peristaltic motion, “like writhing worms,” as Mr. Cruickshank has well expressed it; “the fimbriÆ were also black and embraced the ovaria (like fingers laying hold of an object) so closely and so firmly, as to require some force and even slight laceration to disengage them.”[6] From the great degree of vascularity which is observed in the Fallopian tubes at this period, some anatomists have been induced to consider that their proper tissue was vascular, analogous to the corpora cavernosa penis. Besides the peristaltic motion already mentioned, other movements called ciliary have been observed in the Fallopian tubes at this period, consisting of minute portions of mucous membrane moving briskly and whirling round their axis, apparently for the purpose of propelling the ovum.[7]

As pregnancy advances, the Fallopian tubes undergo other changes as respects their situation, which are worthy of notice. The broad ligaments, in the upper parts of which the Fallopian tubes take their course, are well known to be merely expansions of peritoneum from each side of the uterus, and therefore become gradually unfolded and shorter as the uterus increases in size. “In proportion as the fundus uteri rises upwards and increases in size, the upper part of the broad ligament is so stretched that it clings close to the side of the uterus, so that in reality the broad ligament disappears, no more of it remaining than its very root, viz. its upper and outer corner, where the group of spermatic vessels pass over the iliacs immediately to the side of the uterus. In this state, though the small end of the tube opens in the same part of the uterus as before impregnation, yet the tube has a very different direction. Instead of running outwards in the horizontal direction, it runs downwards, clinging to the side of the uterus. And behind the fimbriÆ lies the ovarium, for the same reason clinging close to the side of the uterus.”[8]

Uterus. The uterus is a hollow fibrous viscus situated in the hypogastric region between the bladder and the rectum, below the intestinum ileum and above the vagina, and is by far the largest of the generative organs. It is of a pyriform figure: its upper portion which is the largest is triangular, becoming gradually smaller inferiorly; that portion of it which is above the spot where the Fallopian tubes enter is called the fundus uteri; the lower and cylindrical portion receives the name of cervix; that between the cervix and fundus is called the body of the uterus.

The parietes of the adult uterus are nearly half an inch in their greatest thickness, which is about the middle of the body, the body being slightly thicker than the cervix, which is of a somewhat harder structure. Near the point at which the Fallopian tubes enter the uterus the parietes become thinner, gradually diminishing from four or five to only one line in thickness.

The cavity of the uterus is triangular, its base being directed upwards, the superior angles corresponding to the points where the Fallopian tubes enter it. The cavity of the uterus is so small, owing to the thickness of its parietes, that they are nearly in contact: it is only four lines in breadth; the fundus, which forms the base of the triangle, is convex both internally as well as externally; whereas, the sides which form the body are convex internally, but somewhat concave externally.

The cavity of the uterus is most contracted at the point where the cervix is united to the body, which here forms the os uteri internum; from this point the cervix gradually dilates as far as its middle portion, when it again contracts; its lower extremity terminates in the upper part of the vagina by an anterior and posterior cushion-like projection, of which the posterior is usually the longest, although from the direction of the uterine axis the anterior is commonly felt lowest in the pelvis. Between these there is a transverse fissure known by the name of os tincÆ or os uteri externum, the lips or labia of which are formed by the two above-mentioned prominences. The internal surface of the body of the uterus is smooth, whereas that of the cervix is uneven, forming upon its anterior and posterior wall a number of delicate rugÆ diverging obliquely in an arborescent form, and hence called the arbor vitÆ. The lips of the os uteri are smooth, except when slight lacerations have taken place during labour.

In the virgin state the uterus is about two inches long, of which the cervix occupies the smaller half: the greatest breadth of the body is sixteen lines; that of the cervix from nine to ten. The uterus which has been impregnated, especially when this has been frequently the case, scarcely ever regains its original dimensions, and the fissure which the os tincÆ forms becomes broader from before backwards. The weight of an adult virgin uterus is from seven to eight drachms, but the uterus which has been once impregnated is seldom less than an ounce and a half. It lies between the bladder and rectum, its upper half being covered by peritoneum, which closely adheres to it. In the adult state it is situated entirely in the cavity of the pelvis; the fundus, which is below the upper edge of the symphysis pubis, is turned forwards and upwards, while its mouth is directed downwards and backwards, so that its long axis is nearly parallel to the axis of the superior aperture of the pelvis.

The uterus is connected to the neighbouring parts by several duplicatures of peritoneum, which are continuous with that portion of it which covers the fundus. The most considerable are the broad or lateral ligaments: these arise from the sides of the uterus, which is enclosed between their anterior and posterior layers or laminÆ; they proceed transversely outwards towards the sides of the pelvic cavity, which is thus divided into two portions, and are then continued into that portion of the peritoneum which lines the cavity.

The round ligaments arise from the sides of the uterus close beneath and a little anterior to the uterine extremity of the Fallopian tubes. They pass between the two layers of the broad ligaments, behind the umbilical arteries, and before the iliac vessels, in a direction upwards and outwards to the external opening of the inguinal canal; they then make a turn round the epigastric artery downwards, inwards, and forwards, and pass through the abdominal ring, and dividing into numerous fasciculi and fibres are gradually lost in the cellular substance of the mons Veneris and upper portion of the labia. Besides consisting of cellular substance and blood-vessels, the round ligaments contain some very distinct bundles of muscular fibres, of which the upper arise from the external layer of uterine fibres, and the lower from the inferior edge of the internal oblique muscle, and pass upwards.

Upon a superficial examination, the structure of the uterus would almost seem to be homogeneous, nevertheless a number of reddish yellow strata interspersed with whitish streaks running from behind forwards may be perceived even in the unimpregnated state; between these strata the vessels of the uterus take their course, forming numerous anastomoses.

There is much difference of opinion among anatomists as to the fibrous structure of the uterus. The majority however agree as to the presence of muscular fibres,[9] some considering that they always exist, while others, and by far the greater number, consider them as appearances peculiar to pregnancy: they are, it is true, extremely indistinct in the unimpregnated state, but they are far from being peculiar to pregnancy, as they are frequently developed by any circumstances by which the formative powers of the uterus are excited. Thus in cases where the uterus has been much distended by some anormal growth, its fibres become much developed and distinctly fasciculated. Lobstein observed them very distinctly in a uterus which had been distended to the size of a seven months’ pregnancy by a fatty tumour.

The uterine fibres have been usually considered as fleshy, but they differ from the red fibres of voluntary muscles, in being of a paler colour, flatter, and remarkably interwoven with each other: nevertheless they appear to be really muscular fibres from the powerful contraction with which they expel the foetus and placenta, and nearly obliterate the cavity of the uterus. In the unimpregnated state they resemble the fibrous coat of an artery, whereas, those of the gravid uterus are more like the fibres of muscle. Most anatomists agree in describing two sets of fibres, viz. longitudinal and transverse. The external layer of fibres appears to form the round ligaments, which seem to have the same relation with them as tendon and muscle. “The fibres arise from the round ligaments, and regularly diverging spread over the fundus until they unite and form the outmost stratum of the muscular substance of the uterus. The round ligaments of the womb have been considered as useful in directing the ascent of the uterus during gestation, so as to throw it before the floating viscera of the abdomen: but in truth it could not ascend differently; and on looking to the connexion of this cord with the fibres of the uterus, we may be led to consider it as performing rather the office of a tendon than that of a ligament.”[10] “On the outer surface and lateral part of the womb, the muscular fibres run with an appearance of irregularity among the larger blood-vessels, but they are well calculated to constringe the vessels, whenever they are excited to contraction. The substance of the gravid uterus is powerfully and distinctly muscular, but the course of the fibres is less easily described than might be imagined: this is owing to the intricate interweaving of the fibres with each other—an intermixture however which greatly increases the extent of their power in diminishing the cavity of the uterus. After making sections of the substance of the womb in different directions, we have no hesitation in stating that towards the fundus the circular fibres prevail, that towards the orifice the longitudinal fibres are most apparent, and that on the whole, the most general course of the fibres is from the fundus towards the orifice.

“This prevalence of longitudinal fibres is undoubtedly a provision for diminishing the length of the organ, or for drawing the fundus towards the orifice. At the same time these longitudinal fibres must dilate the orifice and draw the lower part of the uterus over the head of the child.

“In making sections of the uterus while it retained its natural muscular contraction, I have been much struck in observing how entirely the blood-vessels were closed and invisible, and how open and distinct the mouths of the cut blood-vessels became when the same portions of the uterus were distended or relaxed. This fact of the natural contraction of the substance of the uterus closing the smallest pore of the vessels, so that no vessels are to be seen, where we nevertheless know that they are large and numerous, demonstrates that a very principal effect of the muscular action of the womb is the constringing of the numerous vessels which supply the placenta, and which must be ruptured when the placenta is separated from the womb.”

“Upon inverting the uterus, and brushing off the decidua, the muscular structure is very distinctly seen: the inner surface of the fundus consists of two sets of fibres, running in concentric circles round the orifices of the Fallopian tubes; these circles at their circumference unite and mingle, making an intricate tissue. Ruysch, I am inclined to believe, saw the circular fibres of one side only; and not adverting to the circumstance of the Fallopian tube opening in the centre of these fibres, which would have proved their lateral position, he described the muscle as seated in the centre of the fundus uteri. This structure of the inner surface of the fundus of the uterus is still adapted to the explanation of Ruysch, which was that they produced contraction and corrugation of the surface of the uterus, which, the placenta, not partaking of, the cohesion of the surface was necessarily broken. Farther, I have observed a set of fibres on the inner surface of the uterus, which are not described: they commence at the centre of the last described muscle, and having a course in some degree vortiginous, they descend in a broad irregular band towards the orifice of the uterus: these fibres co-operating with the external muscle of the uterus, and with the general mass of fibres in the substance of it, must tend to draw down the fundus in the expulsion of the foetus, and to draw the orifice and lower segment of the uterus over the child’s head.” (C. Bell, op. cit.)

There are other circumstances which prove the muscularity of the uterus, beyond the mere evidence of its fibres, as seen during pregnancy. “In the quadruped,” as Dr. Hunter observes, “the cat particularly and the rabbit, the muscular action or peristaltic motion of the uterus is as evidently seen as that of the intestines, when the animal is opened immediately after death.” It is also proved by the powerful contraction which it exerts during labour, and “by the thickness of the fibres corresponding with their degree of contraction.” (Ibid.)

The inner surface of the uterus is lined by a smooth or somewhat flocculent membrane of a reddish colour, which is continued superiorly into the Fallopian tubes; inferiorly it becomes the lining membrane of the vagina.

Mucous follicles are only found in the cervix, especially at its lower part: when by chance these become inflamed, the orifice closes, and the follicle becomes more or less distended by a collection of thin fluid. The mucous casts of these follicles have been known by the name of ovula Nabothi, having been mistaken by an old anatomist for Graafian vesicles, which had been detached from the ovary, and conveyed into the cavity of the uterus.

The mucous membrane which lines the cervix uteri is corrugated into a number of rugÆ, between which the mucous follicles are chiefly found.

Before quitting this subject, it will be necessary to point out the changes which the uterus presents at different periods of foetal life, and the great resemblance it has at these periods to the uterus, as it appears in the lower classes of the mammalia. We may, however, observe in the first place, that the uterus is not found to exist as a separate organ until we come to the class mammalia; and even in the lower genera of this class it bears a strong resemblance to the tubular character of the generative organs in the inferior classes of animal life. The nearest to the tubular uterus, and where the transition from the oviduct in birds, &c. to the uterus in mammalia is least distinctly marked, is in the uterus duplex. Although the uterus is double, there is but one vagina into which the two ora uteri open; its low grade of development is marked by the resemblance which each uterus bears to an intestinal tube: there are as yet no traces of a cervix, each os uteri merely forming a simple opening at the lower end of what is little more than a cylindrical canal. We do not find that thickening at the lower extremity of the uterus which distinguishes the cervix in the higher mammalia. This species of uterus is found among a large portion of the rodentia, and is also occasionally met with as an abnormal formation in the human subject. The next grade of uterine development appears under the form of the uterus bicollis. The double os uteri here ceases to exist, and the division begins a little higher up, so that the two cavities of the uterus communicate for a short space: the ova, however, do not reach the common cavity, but remain each in its separate cornu. In this form of uterus, the os uteri is not only single, but the lower portion is thickened, although it has not yet formed a distinct neck or cervix; it is met with among some of the rodentia, and also certain carnivora.

In the uterus bicorporeus, the union of the cornua is higher up, so that the lower portion is single, while the upper part alone is double, consisting of two strongly curved cornua. This conformation is peculiar to ruminating animals. If two ova be present they are separate from each other, each being contained in its own distinct body or cornu, but a portion of the membranes extends along the common cervix, from one body to the other.

A still higher grade is the uterus bifundalis, where the fundus alone is double, the cornu being formed only by this portion. This formation is observed in the horse, ass, &c.: the common cavity is here the receptacle of the ovum, so that in the unimpregnated state, the cornua appear only as appendices, into which a portion of the membranes extend.

In the uterus biangularis, the double formation has nearly disappeared, except at the fundus, where the uterus imperceptibly passes into the tubes: this is the case among the edentata, and some of the monkey tribes.

The highest grade is the uterus simplex: every trace here of the double form is lost; the fundus no longer forms an acute angle, where it bifurcates into two cornua; but is convex. We now for the first time see the divisions of the uterus into body and cervix distinctly marked.

The human uterus presents a similar variety of forms, as it gradually rises in the scale of development during the different periods of utero-gestation. It is at first divided into two cornua, and usually continues so to the end of the third month, or even later; the younger the embryo the longer are the cornua, and the more acute the angle which they form; but even after this angle has disappeared, the cornua continue for some time longer.

The uterus is at first of an equal width throughout; it is perfectly smooth and not distinguished from the vagina either internally or externally by any prominence whatever. This change is first observed when the cornua disappear and leave the uterus with a simple cavity. The upper portion is proportionably smaller, the younger the embryo is. The body of the uterus gradually increases, until at the period of puberty it is no longer cylindrical, but pyriform: even in the full-grown foetus the length of the body is not more than a fourth part of the whole uterus; from the seventh even to the thirteenth year it has only a third, nor does it reach a half until puberty has been fully attained. The os tincÆ or os uteri externum first appears as a scarcely perceptible prominence projecting into the vagina; it increases gradually, in size until the latter months of gestation, when the portio vaginalis is relatively much larger than afterwards.

The parietes of the uterus are thin in proportion to the age of the embryo. They are of an equal thickness throughout at first: at the fifth month, the cervix becomes thicker than the upper parts; between five or six years of age, the uterine parietes are nearly of an equal thickness, and remain so until the period of puberty, when the body becomes somewhat thicker than the cervix.

As the function of menstruation with its various derangements will be considered among the diseases of the unimpregnated state, we proceed to consider these changes which the uterus undergoes during pregnancy as well as during and after labour: these are very remarkable both as regards its structure, form, and size.

Shortly after conception, and before we can perceive any traces of the embryo, the uterus becomes softer and somewhat larger, its blood-vessels increased in size, and the fibrous layers of which its parietes are composed looser and more or less separated. The internal surface when minutely examined has a flocculent appearance, and very quickly after conception becomes covered with a whitish paste-like substance, which is secreted from the vessels opening upon it; this pulpy effusion soon becomes firmer and more dense; it bears a strong analogy to coagulable lymph, and forms a membrane which lines the whole cavity of the uterus, and which in the course of a few weeks (from changes to be mentioned hereafter) crosses the os uteri and thus closes it. The uterine cavity in a short time becomes still farther closed by the canal of the cervix being completely sealed, as it were, by a tough plug of gelatinous matter which is secreted by the glandules of that part.

The structure of the uterus becomes remarkably altered; its fibrous structure is much more apparent; in fact, it is only during pregnancy, or when the uterus has been distended by some anormal growth, that we are able to detect the uterine fibres with any degree of certainty. This has led some anatomists to consider that they are only formed at such periods, a supposition which is not very probable; at any rate they now become very distinct: hence the uterus does not owe its increasing size to mere extension, but it evidently acquires a considerable increase of substance, a fact which is not only proved by examining the contracted uterus after labour at the full period, but also by comparing its weight with that of the unimpregnated organ. The adult virgin uterus weighs about one ounce, whereas the gravid uterus at the full term of pregnancy, when emptied of its contents, weighs at least twenty-four ounces, showing that there has been an actual increment of substance in the proportion of one to twenty-four. Having ascertained this point, it next becomes a question, whether the parietes of the gravid uterus increase in thickness during pregnancy, or whether they become thinner. Meckel, who is one of the greatest modern authorities on these subjects, states that from careful admeasurement of sixteen gravid uteri at different periods of gestation, he finds the parietes become thicker during the first, second, or third months, but after this period they become gradually thinner up to the full time: they are thicker in the upper parts of the uterus, whereas inferiorly they are a third or nearly a half less.

Nothing proves the actual increase of bulk and substance in the uterus more than its appearance when contracted immediately after labour at the full term; it forms a fleshy mass as large as the head of a new-born child, the parietes of which are at least an inch in thickness.

“The spongy or cellular tissue (says M. Leroux) becomes considerably developed during pregnancy, and its porous cells increase in proportion as the uterus dilates, more especially at the fundus and the spot where the placenta is attached, where they become so large as to admit a goosequill. The internal membrane is pierced with numerous orifices, of which some are the mouths of arteries, and others communicate with the cells already mentioned. This membrane also during pregnancy forms those irregular tufted rugÆ, which serve to give a more intimate connexion between the uterus and the placenta. In the unimpregnated uterus and in the intervals between the menstrual periods the little orifices which are observed in the lining membrane of the uterus contain only a transparent lymph, which lubricates the interior of the uterus; during the appearance of the menses they contain blood, and during pregnancy they are connected with the vessels of the placenta and chorion.”[11]

There is no circumstance in which the gravid uterus differs more from the unimpregnated than in the size and termination of its blood-vessels. The arteries, both spermatic and hypogastric, are very much enlarged. The hypogastric is commonly considerably larger than the spermatic, and we very often find them of unequal sizes in the different sides. They form a large trunk of communication all along the side of the uterus, and from this the branches are sent across the body of the uterus both before and behind. The cervix uteri has branches only from the hypogastrics, and the fundus only from the spermatics; or, in other words, the hypogastric artery gives a number of branches to the cervix, besides sending up the great anastomosing branch, and the spermatic artery supplies the tube and fundus uteri before it gives down the anastomosing branch on the lateral parts of the uterus. All through the substance of the uterus there are infinite numbers of arteries large and small, so that the whole arterial system makes a general network, and the arteries are convoluted or serpentine in their course.[12] Hardly any of the larger arteries are seen for any length of way upon the outside of the uterus. As they branch from the sides where they first approach the uterus, they disappear by plunging deeper and deeper into its substance.

The arterial branches which are most enlarged are those which run towards the placenta, so that wherever the placenta adheres, that part appears evidently to receive by much the greatest quantity of blood, and the greatest number both of the large and small arteries at that part pass through to the placenta, and are necessarily always torn through upon its separation. The veins of the uterus would appear to be still more enlarged in proportion than the arteries. The spermatic and hypogastric veins in general follow the course of the arteries, and like them anastomose on the side of the uterus. From thence they ramify through the substance of the uterus, running deeper and deeper as they go on, and without following precisely the course of the arterial branches. They form a plexus of the largest and most frequent communications which we know of in the vessels of the human body, and this they have in common with the arteries that their larger branches go to, or rather come from, that part of the uterus to which the placenta adheres: so that when the venous system of the uterus is well injected, it is evident that that part is the chief source of returning blood. Here, too, both the large and small veins are continued from the placenta to the uterus, and are always necessarily broken, upon the separation of these two parts. As I know no reason for calling the veins of the uterus sinuses, and as that expression has probably occasioned much confusion among the writers upon this subject, I have industriously avoided it.[13]

The form of the uterus changes considerably during pregnancy: the upper part appears to increase in greater proportion than the lower, a fact which appears to be proved from the alteration which takes place in the relative position of the Fallopian tubes, which are situated much lower down the sides of the uterus at full term than in the unimpregnated state, nor do they entirely regain their former position after labour, until the female has attained an advanced age; hence as the cervix diminishes in length during the latter half of pregnancy, it follows that the difference in point of size between the fundus and the body of the uterus, and this part will be continually increasing.

As the uterus increases, the fundus of course rises and can be felt through the distended abdominal parietes: its anterior surface, especially in the latter month of pregnancy, lies immediately behind the anterior wall of the abdominal cavity, and pushes the small intestines upwards, backwards, and to the sides.

The form of the gravid uterus differs also from that in the unimpregnated state in other respects, and this difference appears to depend in great measure upon its increase of size, and upon the form of the cavities which it occupies. Thus in the unimpregnated state when it occupies the cavity of the pelvis, its anterior surface which corresponds to the bladder is flattened; whereas its posterior surface, which is turned towards the hollow of the sacrum, is convex; it is however the reverse during the latter half of pregnancy. The anterior surface is now strongly convex, being merely covered by the yielding anterior wall of the abdomen; whereas posteriorly the uterus is nearly concave, corresponding to the solid convexity of the lumbar vertebrÆ, a fact which may be easily ascertained by examining the abdomen of a patient in the last month of pregnancy while lying down. The situation and position of the uterus are also changed in the unimpregnated state; the fundus is inclined somewhat backwards, the os uteri being nearly in the centre of the pelvic cavity, but the gravid uterus during the latter half of pregnancy has its fundus strongly inclined forwards and the os uteri directed backwards towards the upper part of the hollow of the sacrum.[14]

A minute and intimate knowledge of the changes and appearances which the uterus presents at every period of pregnancy, is essential to the diagnosis and treatment of the various derangements to which this process is subject. The numerous and important questions in medical jurisprudence connected with pregnancy can alone be determined by its means; and it is only by more close and attentive observation of every step in the gradual development of the uterus up to the full term of gestation, that we can expect to increase our means of forming a correct and certain diagnosis in those cases of doubtful pregnancy, where not merely professional reputation is more or less at stake, but the character, happiness, and even life of the individual upon whose case we are required to decide.

During the first month of pregnancy the changes are not very appreciable upon examination during life. The uterus has become larger, softer, and more vascular, much as it does during a menstrual period. The portio vaginalis of the cervix, which in the unimpregnated state is hard and almost cartilaginous to the feel, becomes softer and larger:[15] the transverse fissure which the os uteri forms is more oval.

In the second month, the abdomen becomes somewhat flat: the portio vaginalis can be now reached by the finger with greater ease than at any time of pregnancy, which is not from the uterus itself being lower in the pelvis, but from not yet having altered its position; any increase of its size therefore will cause its inferior extremity to be felt lower down and nearer to the os externum. The os uteri has undergone a considerable change, inasmuch as its edges have lost their lip-like figure; they now form a ring or rather dimple-like concavity at the lower end of the cervix, its canal being closed by the gelatinous plug already mentioned.

In primiparÆ, or women pregnant for the first time, the margin of the os uteri thus closed is not only circular but perfectly smooth; whereas in multiparÆ, not only is the cervix usually larger in every direction, but the os uteri itself is larger, thicker, and of an irregular shape; it is also knotty here and there from little callous cicatrices, where its edge has been torn in former labours.

In the third month of pregnancy the uterus rises above the brim of the pelvis. A slight protrusion of the abdomen may be sometimes observed above the pubes; the os uteri is not reached so easily as in the preceding month. The alteration which takes place in the situation of the uterus during the third month appears to result from gradual shortening of the broad ligament as it increases in size. As the uterus rises it pushes up that portion of the small intestines which rests upon it; these however being confined by the mesentery to the spine, and therefore prevented ascending before the uterus, at length slip down behind it, and the fundus being freed from the superincumbent pressure rises in a direction upwards and forwards into the cavity of the abdomen. The direction of the uterus becomes much altered; the os uteri is no longer in the middle of the pelvic cavity, but inclines towards the upper part of the hollow of the sacrum, whereas the fundus approaches more and more to the anterior parietes of the abdomen.

In the fourth month, the fundus uteri has risen about two or three fingers’ breadth above the symphysis pubis; this is not very easily ascertained even in a thin person, still less where the patient is stout and the parietes of the abdomen therefore thick. The directions which the celebrated Roederer has given for making an examination of the abdomen during the early months of pregnancy, are well worthy of notice. Having evacuated the bladder and rectum, the patient should be placed in a half-sitting posture with the knees drawn up, so as to relax the abdominal parietes as much as possible: she must then breathe slowly and deeply; and if the hand be suddenly pressed against the abdomen a little above the symphysis pubis, at the moment of her making a full expiration, we shall in all probability feel the hard globe of the uterus.

In the fifth month, the fundus will be felt half way, or a little more, between the symphysis pubis and umbilicus. The increased size of the abdomen cannot be concealed by the dress; the portio vaginalis has become distinctly shorter, and the os uteri is situated higher in the pelvis and more posteriorly.

In the sixth month, the fundus has risen as high as the umbilicus; the irregular folds of the skin which form the fovia umbilici or navel depression begin to disappear; the first perceptible movements of the child may occasionally be felt; the portio vaginalis has lost half its length, being scarcely half an inch in length.

In the seventh month, the fundus rises an inch or so above the umbilicus, the folds of which have nearly disappeared. In some cases it begins to protrude, forming a species of umbilical hernia: this varies a good deal in different individuals, being more marked in primiparÆ; whereas in women, whose abdomen has been distended in previous pregnancies, little or no convexity of the navel is produced until a later period, and not always even then, the umbilical depression being merely diminished in point of depth, and its folds not so strongly marked. The movements of the child are now perfectly distinct; the portio vaginalis is still shorter, and approaches more and more to the upper part of the hollow of the sacrum. The anterior portion of the inferior segment of the uterus, or that part which extends from the os uteri towards the symphysis pubis, is now considerably developed and convex, and on pressing the point of the finger against it, the presenting part of the child will be felt. When this is the head as is usually the case, it will feel like a light ball which rises when pushed by the finger, but which, if the finger be held still, in a few moments descends and may again be felt.

In the eighth month, the fundus has risen half way between the umbilicus and the scrobiculus cordis. The abdomen has increased considerably in size, and has become more convex; the umbilical depression in primiparÆ has entirely disappeared. The portio vaginalis is still shorter, being barely a quarter of an inch in length. The os uteri is so high up as not to be reached without difficulty; the presenting part of the child can be distinctly felt.

In the ninth month, the fundus has reached nearly to the scrobiculus cordis, and by the end of the month is quite in it; this is more especially the case with primiparÆ: the anterior parietes of the abdomen not allowing the fundis to incline so strongly forwards, the oppression of breathing is therefore more marked in them than in multiparÆ, for the fundus uteri rising so high prevents in great measure the action of the diaphragm, so that the chest is expanded by other muscles; hence the shortness of breath and inability of moving, so frequently complained of at this period of utero-gestation. The portio vaginalis is still shorter, and in the primipara forms little more than a soft cushiony ring which marks the os uteri. The inferior part of the uterus is becoming more spherical, and is usually occupied by the presenting part of the child: this latter is no longer so moveable as before, its size as also its weight being evidently increased. That portion of the uterus which extends between the symphysis pubis and os uteri is now not only more convex but lower in the pelvis than the os uteri itself.

During the last four weeks of pregnancy a considerable change is observed. The fundus is now lower than it was in the preceding month, being about half way between the scrobiculus cordis and umbilicus; the abdomen has, as it is called, fallen; and from the diaphragm being now able to resume its functions the breathing becomes more easy, and the female feels more comfortable and capable of moving about. On examination per vaginam the anterior portion of the inferior segment of the uterus will be felt still deeper in the pelvis: if the head presents it distends this part of the uterus, so that, in many cases, we have to pass the finger round it before we can reach the os uteri, which is now in the upper part of the hollow of the sacrum. All traces of the cervix have now disappeared, it having been required to complete the full development of the uterus; the situation of the os uteri itself is marked merely by a small depression or dimple; there is no longer any distinction between the os uteri internum and externum; the edges of the opening are so thin as to be nearly membranous, but remain closed in primiparÆ until the commencement of labour.[16]

In women who have had several children, a considerable difference is observed as regards the state of the cervix and os uteri: the cervix does not undergo that shortening during the latter half of pregnancy, which is the case in a primipara, a portion of it at least remaining up to the full term of utero-gestation: in many cases, especially where the female has had a large family, it is nearly an inch long at this period; nor is the lower portion of the uterus so spherical as in the primipara; to this circumstance may probably be attributed the fact of the head not descending so deep into the pelvis just before labour. In multiparÆ the os uteri is also very different: instead of being perfectly round with its edges smooth, it is irregular and uneven, and seldom loses altogether the lip-like shape of the unimpregnated state in consequence of the greater thickness and elongation of its lips from former labours; its edges here and there is uneven and knotty, from little callous cicatrices, where it has been torn; moreover it does not remain closed till the commencement of labour, but the os uteri externum (commonly called os tincÆ,) and sometimes even the os uteri internum will be more or less open during the last three or four weeks of pregnancy. These peculiarities are of great importance in coming to a conclusion as to whether a patient be in her first pregnancy or not: although not invariable in the utmost sense of the word, still their occurrence, even after a single labour, is sufficiently frequent to make them worthy of careful observation. Indeed, on more than one occasion, we have known them occur even after a miscarriage, a circumstance on the strength of which the patient had ventured to deny that she was pregnant. On the other hand, we sometimes meet with the os uteri in a second pregnancy so little altered by the effects of the previous labour, that it would be extremely difficult to come to a decision.

When labour is over, the uterus contracts very considerably, and, in a few days after, its parietes will be found at least an inch in thickness. It now gradually diminishes in size, and continues to do so for some weeks; the blood-vessels contract, and losing the peculiarly loose spongy structure of pregnancy it becomes harder, firmer, and more compact. It nevertheless remains softer and larger than in the virgin state, and does not attain its original size and hardness until an advanced period of life.

The os uteri, which in the latter months of pregnancy had formed a circular opening, resumes its former shape, except that its lips, especially the posterior one, which are more or less irregular and uneven, are thicker and longer than in the virgin state. For the first weeks after labour, the os uteri is high in the pelvis, soft, and easily admits the tip of the finger; at the end of the second week it is much lower in the pelvis, and no longer permits the finger to pass. Immediately after labour, the contracted uterus forms a hard solid ball, the size of a new-born child’s head; this state of contraction is not, however, of long continuance: in the course of half an hour, or even less, it begins to increase in size, becoming softer and larger, and continuing to increase slowly for some hours, when it again gradually diminishes, until, as before observed, it approaches its original size in the unimpregnated state. The state of powerful contraction in which the uterus is felt immediately after labour, after a time gradually relaxes; its spongy texture, from which the blood had been forcibly expelled by the violent action of its fibres, becomes again filled with blood; the organ swells and becomes softer and more bulky, and the orifices of the vessels which open into the cavity of the uterus are again partly pervious, and emit a sanious fluid called the lochia. This state lasts for two or more days after delivery, when the vessels begin to recover their former caliber, and lose that degree of dilatation peculiar to the gravid state. The lochia become less and less coloured, and now, and not before the uterus undergoes that gradual diminution of size and bulk which we have just alluded to.

The copulative or external organs of generation are the vagina, hymen, clitoris, nymphÆ, and labia, the three last being known by the term vulva.

Vagina. The vagina is a canal of about four inches in length and one in breadth, broader above than below; its parietes are thin and are immediately connected with the uterus. It envelopes the portio vaginalis of the uterus at its upper or blind extremity (fundus vaginÆ,) and is continuous with its substance; inferiorly, where it is narrowest, it passes into the vulva. It is situated between the bladder and rectum, and attached to each by loose cellular tissue. Its direction differs from that of the uterus, for its axis corresponds very nearly with that of the pelvic outlet, running downwards and forwards. Posteriorly it is somewhat convex, anteriorly concave.

The vagina consists of two layers; the external, which is very thin, firm, of a reddish-white colour, and continuous with the fibrous tissue of the uterus; and a lining mucous membrane which is closely united to it. This latter is much corrugated, especially in the virgin state, the rugÆ running transversely in an oblique direction, and gathered together on its anterior and posterior surface, forming the columna rugarum anterior and posterior, which appear to be a continuation of the corrugations which form the arbor vitÆ of the cervix.

In the upper part of the vagina there are considerable mucous follicles, which moisten the canal with their secretion, and which during sexual intercourse, and particularly during the first stage of labour, pour forth an abundant supply of colourless mucus for the purpose of lubricating the vagina, and rendering it more dilatable. Near its orifice, especially at the upper part, the veins of the vagina form the plexus retiformis, a congeries of vessels which has almost a cellular appearance, and from this reason has been called the corpus cavernosum of the vagina; it appears to be capable of considerable swelling from distension with blood, like the corpus cavernosum penis, and by this means serves to contract still farther the os externum during the presence of venereal excitement. A similar disposition to form plexuses of vessels is seen in the venous circulation of the nymphÆ, bladder, and rectum.

Hymen. The lining membrane of the vagina is of a reddish-gray colour, interspersed here and there, especially at its upper part, with livid spots like extravasation. At the os externum it forms a fold or duplicature called hymen, running across the sides of the posterior part of the opening, and usually of a crescentic figure, the cavity looking upwards. The duplicatures of membrane are united by cellular tissue. In some instances, the hymen arises from the whole circumference of the os externum, having a small orifice in the centre for the escape of the menses and vaginal secretions: in some rare cases it is cribriform; and in others it completely closes the vaginal entrance. When torn in the act of sexual intercourse, it generally forms three or four little triangular appendages, called carunculÆ myrtiformes, arising from the posterior and lateral portions of the os externum.

From the identity of its fibrous coat with that of the uterus, the vagina possesses considerable powers of contraction, when excited by the presence of any body which distends it; hence it is a valuable assistance to the uterus during labour: it also stands in the same relation to the abdominal muscles that the rectum does, so that as soon as it is distended by the head, &c. it calls them into the strong involuntary action, which characterizes the bearing down pains of the second stage of labour. The orifice of the vagina (os externum) is surrounded by a thin layer of muscular fibres, which arise from the anterior edge of the sphincter ani; they enclose the outer margin of the vagina, cover its corpus cavernosum, and are inserted into the crura clitoridis at their union. It has been called the sphincter or constrictor vaginÆ, and assists the corpus cavernosum still farther in contracting the os externum.

Clitoris. The clitoris is an oblong cylindrical body, situated beneath the symphysis pubis, arising from the upper and inner surface of the ascending rami of the ischium, by means of two crura of about an inch long, and uniting with each other at an obtuse angle. It terminates anteriorly in a slight enlargement, called the glans clitoridis, which is covered with a thin membrane or a loose fold of skin, viz. the preputium clitoridis. It is a highly nervous and vascular organ, and like the penis of the male, is composed of two crura and corpora cavernosa, which are capable of being distended with blood; they are contained in a ligamentous sheath, and have a septum between them. The clitoris is also provided with a suspensory ligament, by which it is connected to the ossa pubis. Like that of the penis, the glans clitoridis is extremely sensible, but has no perforation. Upon minute examination, it will be found that the gland is not a continuation of the posterior portion of the clitoris, but merely connected with it by cellular tissue, vessels, and nerves; the posterior portion terminates on its anterior surface in a concavity which receives the glans. In the glans itself there is no trace of the septum, which separates the corpora cavernosa. On the dorsum of the clitoris several large vessels and nerves take their course, and are distributed upon the glans, and upon its prepuce are situated a number of mucus and sebaceous follicles.

The crura clitoridis at their lower portion are surrounded by two considerable muscles, called the erectores clitoridis, arising by short tendons close beneath them from the inner surface of the ascending ramus of the ischium, and extending nearly to their extremity.

NymphÆ. The nymphÆ or labia pudendi interna, are two long corrugated folds, resembling somewhat the comb of a cock, arising from the prepuce and glans clitoridis, and remaining obliquely downwards and outwards along the inner edge of the labia, increasing in breadth, but suddenly diminishing in size. At their lower extremity they consist of a spongy tissue, which is more delicate than that of the clitoris, but resembles considerably that of the glans, of which it appears to be a direct continuation. It has been called the corpus cavernosum nympharum, and is capable of considerable increase in size when distended with blood. The two crura of the prepuce terminate in their upper and anterior extremities; they are of a florid colour, and in their natural state they are contiguous to, and cover the orifice of the urethra. The skin which covers them is very thin and delicate, bearing a considerable resemblance to mucous membrane, especially on their inner surface, where it is continuous with the vagina; externally it passes into the labia.

The space between the nymphÆ and edge of the hymen is smooth, without corrugation, and is called vestibulum.

Close behind the clitoris, and a little below it, is the orifice of the urethra, lying between the two nymphÆ: it is surrounded by several lacunÆ or follicles of considerable depth, secreting a viscid mucus; its lower or posterior edge is, like the lower portion of the urethra, covered by a thick layer of cellular tissue, and a plexus of veins, which occasionally become dilated and produce much inconvenience; it is this which gives the urethra the feel of a soft cylindrical roll at the upper part of the vagina; and in employing the catheter, by tracing the finger along it, the orifice will be easily found.

Labia. The labia extend from the pubes to within an inch of the anus, the space between the vulva and anus receiving the name of perineum.

The opening between the labia is called the fossa magna: it increases a little in size and depth, as it descends, forming a scaphoid or boat-like cavity, viz. the fossa navicularis.

The labia are thicker above, becoming thinner below, and terminate in a transverse fold of skin, called the frÆnulum perinei, or fourchette, the edge of which is almost always slightly lacerated in first labours. They are composed of skin cushioned out by cellular and fatty substance, and lined by a very vascular membrane, which is thin, tender, and red, like the inside of the lips; they are also provided with numerous sebaceous follicles, by which the parts are kept smooth and moist.