adhere to Dr. Duncan's definition of presentation as "that point of the surface of the child's head through which the axis of the developed pelvic canal passes," I think it will be found that the posterior extremity of the sagittal suture, or the angle formed by the two parietal bones, will be found towards the centre of the canal of the pelvis. Of course it gradually advances as the occiput approaches the arch of the pubis, and then more rapidly in proportion to the degree of extension that ensues, the presenting part being always central to that particular plane through which the head is passing.

This rejects altogether the usual mode of judging as to what part presents. We cannot determine this question by the position of the caput succedaneum, for reasons Dr. D. has well detailed. Neither can the question be settled by examining what part of the child's head is felt at the orifice of the vagina, because, in the first place, the orifice of the vagina is never parallel with any plane of the pelvis, and should be regarded as situated at the anterior part of the cavity; and in the second place, the part of the head felt towards the orifice of the vagina is continually changing during the process of rotation, so that in many cases the anterior part of the parietal bone, its posterior part, and then the side of the occiput may be felt in succession at the opening of the vagina before the occipital protuberance fairly emerges. If, however, the finger be directed to the true vertex, this part will be found nearly stationary during the process of rotation, except that it advances slowly along the perineum. If, therefore, the occipito-mental diameter be thus constantly coincident with the obstetric axis, and the whole posterior portion of the head be represented by the figure of a ball, each of its diameters measuring three and a half inches, it follows, I think, that there is a necessary parallelism of this equatorial plane with the planes of the pelvis. This view is not invalidated by the fact, recorded by Nægelè, that in many instances the right parietal protuberance escapes first at the inferior strait, as this would only show that the head is small enough to be delivered before rotation is complete, but is not really inconsistent with the synclitism for which we contend. I must, however, believe that careful observation will show that such an escape of the parietal protuberance occurs in easy labors only; that when the customary resistances are present, as in first labor, the head being of normal size, each parietal protuberance finds its exit upon the same level at the tubers of the ischia, while the sagittal suture and anterior fontanel will be found in the middle line of the perineum.

Dr. Duncan's declarations, that " continued synclitism is con

ceivable during and after rotation," and, moreover, "that there arises from the mechanism a direct tendency to the production of the synclitic condition there can be no doubt," gives me much pleasure. But in another place he observes, "The tendency to the synclitic movement is prevented by two causes. First, the driving force operates chiefly on the occipital portion of the head, through the spine; and, second, the greater resistance of the pelvis posteriorly, as compared with that anteriorly towards the symphysis. These prevent the synclitic movement.'

How these two circumstances prevent the tendency to a synclitic movement, I am at a loss to comprehend; for, on the contrary, they seem to me to necessitate synclitism of the head, by increasing the flexion of the child's head when it is high up, and its extension when low down in the pelvis or in the vagina.

Respecting the quotation given by Dr. Duncan from Dorhn, as to the "shearing" of the child's head, I do not, perhaps, comprehend his full meaning, but I must agree with Dr. Duncan in believing that the vertical shear to which he alludes does not occur at the superior strait in cases of natural labors, but I have observed it in cases where the conjugate diameter was contracted. In respect to the second or lateral shear, it includes, if I understand it, those circumstances which determine the rotation of the head in the inferior part of the pelvis, and may, as he observes, give rise to the lateral shearing of the head, as described by Dorhn. I should not, however, regard this as of any practical importance. My own belief is that the head of the child, during descent, in all the occipito-anterior positions, impinges much more firmly against the anterior portions of the cavity, and that the rotation of the head is dependent, in these cases, upon one or other, as the case may be, of the anterior inclined planes of the pelvis, as formed by the bones of the pubis and ischium, and as they are prolonged by the levatores ani muscles, But these are points not now under review.

etc.

I thus have been endeavoring to maintain the synclitic movement of the child's head in cases of natural labor, as true, both theoretically and practically. I cannot insist upon its mathematical accuracy, for the ever-varying size of the child's head, and the degree of resistance it meets with from the os uteri and from the bones of the pelvis, which must influence continually its degree of flexion or extension, defy any attempts at mathematical accuracy. I would only repeat that the head passes more readily when it presents its cervico-bregmatic plane, and that the greater the resistance the more perfect will be the flexion, and the more exact will be the parallelism or synclitism of

the equatorial plane of the head with the various planes of the pelvis and vagina.

If this fact be substantiated, its practical importance can hardly be estimated. This assertion needs no demonstration to any experienced accoucheur. If the great occipital extremity of the head descends, in a natural labor, in such a manner that the occipito-mental diameter always coincides with the axis of the obstetric canal, whether straight or curved, and that the cervico-bregmatic plane of the head, with its diameters of equal length, is parallel to the successive planes of the pelvis through which it passes, it results: That it is the great business of the acconcheur during the whole process of descent, to insure this parallelism by facilitating, during the first portion of the descent, the process of flexion of the head, and during the last, by facilitating its extension.

Hence, also, in all obstetric operations the same principle must regulate the hand of the practitioner. The blades of the forceps, for example, should always be applied as nearly as practicable in the direction of the occipito-mental diameter, and traction effort be made in the axis of the obstetric canal, inasmuch as then the longest diameter of the head will be coincident with the obstetric axis, and the cervico-bregmatic circumference will be parallel planes of the pelvis and vagina. This, as all experience demonstrates, is not only themost natural, but also the easiest mode for the transit of the head.

THROMBUS OF THE VULVA. A Clinical Lecture, delivered at Bellevue Hospital, by FORDYCE BARKER, M. D., Professor of Clinical Midwifery and Diseases of Women, Bellevue Hospital Medical College, N. Y. (Med. Record, Sept. 1, 1870.)

GENTLEMEN :-A long time ago, at the very commencement of my practice, I was called to attend a young woman in labor. Every thing seemed to be progressing favorably, when suddenly the patient screamed, threw herself to the other side of the bed, and appeared to lose all self-control. A few minutes before this I had made an examination, and found the cervix dilated, and the head descended into the pelvic cavity. I was promising myself a speedy termination of the labor, till startled by the interruption of it just described.

The patient was suffering such intense pain, and the parts were so tender, that it was some little time before I could get another examination. Then I, at first, discovered a tumor, of a hardness resembling that of the foetal head; and I thought the foetus was just escaping from the vulva, and that it was the

agony attending this which had brought the patient to her distressing condition. But I soon found that she was losing a good deal of blood, and that the uterine contractions had ceased. Her excitement and anxiety I was able to calm by perfect selfpossession; but I was unable to make a satisfactory diagnosis. The indication was evidently to prevent loss of blood, though as to what the hemorrhage meant I had not the least idea. To fulfil this indication I applied a saturated solution of alum, and made a pretty strong pressure upon the tumor, which I kept up for an hour or two, the labor-pains all the while being stopped.

The case being so obscure, I decided to call a consultation. A physician much older than myself was sent for, who made a comparatively hasty examination, and at once pronounced the case one of placenta prævia; saying that he had often had such cases; that owing to the severe pain produced by my application of alum and compression, I had arrested the labor, and it might be some hours before the pains returned, when he would be sent for again. On the whole, he damned me with faint praise; thought I had done very well, considering that I was a very young man, just beginning practice; and, as I afterwards learned, censured me to the family for the ridiculous folly I had been guilty of in making my applications. He left, with directions to be called when the labor recommenced. I was hurt and humiliated, but not convinced. I found, too, that the consulting physician had not favorably impressed the family, while I had rather won their confidence and sympathy.

In the mean time my measures had stopped the hemorrhage. About an hour later, it returned to a considerable amount; and, as the patient's chief danger seemed to be from loss of blood, I saw nothing better than to renew them. They could certainly do no harm. In applying the compresses I embraced the opportunity to make examinations, and presently came to the conclusion that there must have been some solution of continuity in one of the labia, to account for the bleeding. The nurse was a sensible woman; and, directing her to keep on the alum and compresses, I went home to consult my books. Though my library was tolerably rich in works on obstetrics, I could find nothing, as I hastily turned them over, except a short description of extravasation into the labium, with no directions for treatment. I reflected that it would not do for me, a young, unmarried man, with a reputation to make or to mar, to let the woman die with a child in her. So I turned over my books again for directions as to the use of the forceps, took my forceps, and went back to the house.

During my short absence the tumor had so increased in size that it was with difficulty I could pass my fingers into the vulva, especially since it caused the patient so much sufferingfor this was long before the days of anesthesics. The head was pretty low down, but the woman had lost still more blood. I said to myself: With this bleeding and this tumor there is no chance of the labor's terminating spontaneously; or, if there be such a possibility, and I wait for it, there must at least be a great loss of blood; the patient will probably die, and that will be ruin to me. I applied the forceps and delivered a living child. This was my first forceps case. Immediately following delivery there was a tremendous gush of blood, and almost as soon as the blood had escaped the tumor filled up again. With no authorities and no experience to guide me, I could only follow a sort of instinct, with the conviction that it was leading me right, or, perhaps, a non-formulated logic which it would have been difficult for me to defend. I am sure, gentlemen, that no general in time of battle, considering that he held the fate of an army or a nation in his hands, ever felt a heavier weight of responsibility than I did here; and, although this was twenty-eight years ago, every incident and detail of the case is stamped indelibly on my memory, as vividly as it had occurred but yesterday. From further examination I satisfied myself that laceration of the labium had taken place, and that the extravasation of blood was into this. I recollected that Hunter, in his work "On the Blood" (which I had studied carefully in my early pupilage, and which still remains a great favorite with me), had described the case of a woman who had accidently fallen upon the handle of a water-pail, causing laceration of the labium with great hemorrhage. Hunter had left the coagulum to compress the lacerated vessels and stop the bleeding; had then poulticed the part and bled the patient, to keep the tissues soft and relieve pain. Suppuration had taken place, with discharge of clots, and eventual recovery with a slough. This case had not occurred in pregnancy, but it was my only guide, and I followed the plan of treatment there indicated. It was some time before my patient recovered. She had a gangrenous slough, by which the whole labium was completely destroyed. The woman got well, however, though with only one labium, and the child also lived.

Now, gentlemen, if you look through all the text-books on midwifery in the English language, including translations into English, you will not find in one of them plain directions for the management of such a complication of labor as this. To be sure, thrombus of the vulva is now described in several