Out of these same forty cases, one lived to 29 years, one to 35, and one to 57.

Finally, in what percentage of adult hearts does the foramen ovale persist? In accord with current opinion, text-books nearly all describe it as an abnormality, and most of them give its occurrence to be never more often than one in five. Some weeks ago Dr. Keiller, in looking over some half dozen hearts in another investigation, was struck by the fact that in four or five of the six a definite foramen ovale existed. At his suggestion, I made a study of thirty-one other dissecting room specimens, finding the foramen in sixteen, or in a little over 50 per cent. Since paying a somewhat closer attention to the subject lately, I find that some authorities do describe its presence as being one in three or four. The London Anatomical Society has made an investigation of three hundred and ninety-nine adult hearts, while Fawcett and Blanchford, of Bristol, have examined three hundred and six. Out of this total of seven hundred and five, the foramen was present in 28.36 per cent.; in males, 26.3 per cent.; in females, 31.3 per cent. This relatively more frequent occurrence in females is a dubitable question. During the last few weeks I have been able to include in my list a total of fifty hearts, having added from the dissecting room and post-mortem table to the thirty-one of my first investigation. In toto, I find the foramen ovale in 46 per cent., but I believe this percentage to be a little too high. The aperture was not a mere round opening between the auricles, nor yet a slit. The usual anatomical condition partook of the nature of an oblique channel of some length (to 3 or 4 cm.), with a middle constriction. In some instances, the larger aperture was into the right, in others into the left auricle. Some specimens presented double openings into one or other auricular cavities. In one hundred and fifty-eight of the seven hundred and five cases above cited, in which the size of the foramen was measured, it varied from 1 to 15 mm.; average in seventy-four, 4.6 mm. In my cases the size varied from that admitting a small probe to 15 mm.; average in ten, 4.5 mm. On account of its oblique direction and the valve-like action its walls must exert, the blood-stream can hardly pass from auricle.

to auricle. The following important points, while not in every sense conclusions from this paper, may be cited:

1. A patent foramen ovale probably exists in one case in three. 2. When closed, this usually occurs several months after birth. 3. When only slightly patent, no cardiac embarrassment ensues. 4. The right-sided posture of a new-born child is a matter of little import. I fully realize that this is not a settled question. The conclusion was reached after talking the subject over with several learned practitioners, and after a due consideration that the process of closure is a true physiological process.

5. A persistent foramen ovale is usually present in pronounced types of so-called cyanosis or "blue disease."

Before closing, I wish to state that I have purposely, at the risk of being obscure, omitted to read the statistics of the various specimens in which the foramen ovale was observed, since such a reading would have been only wearisome.

DISCUSSION.

DR. KEILLER: It is most interesting to know that these conditions are found. If you found a foramen ovale like that in an autopsy on a child of six months you would be certain to put it down as the cause of death. There is not nearly enough known as to the time when the foramen ovale closes, and the paper opens up a field of very useful inquiry. Many of the things he told us were eye-openers to me. Of course it is unfortunate that we have so few post-mortems on children, as it is in such cases we would get the most valuable information.

DR. CARTER: The rarity with which we see cases clinically showing symptoms due to this cause, and the remarkable frequency with which the anatomical condition is revealed at autopsies, shows that the condition must frequently exist without causing any untoward symptoms.

SKIAGRAPHY OF THE RENAL VESSELS.

W. KEILLER, M. D.,

GALVESTON, TEXAS.

Two years ago I presented to this Association a paper setting forth the result of dissections I had made of the blood-vessels of the kidneys and showing their relation to the operation of nephrotomy. The paper is to be found in the TRANSACTIONS for 1900, and was published in American Medicine, April 6, 1901. About the same time, working entirely independently and by a different method, Max Brödel arrived at similar results. His work was much more exhaustive than mine, his results reached by more perfect methods, and his paper in the Johns Hopkins Hospital Bulletin and the Transactions of the Society of American Anatomists, December, 1900, is illustrated with drawings which can seldom be equalled, never excelled, for artistic execution and scientific accuracy. The dissections were made, I believe, at the instance of Dr. Howard Kelly, and the operation of nephrotomy formulated by Dr. Kelly on these dissections puts this operation on a sound anatomical basis.

The plates which I present to you today confirm Max Brödel's results by a method which has not so far as I know been applied to the renal vessels, namely, by X-ray pictures of the injected vessels and ureter. They are interesting also as being not the first, but among the first, published pictures of vessels taken by the X-rays, and as giving a very beautiful and very accurate idea of the distribution of these vessels. Briefly, the method consists in the injection of the vessels (the arteries only in most of the specimens), and the ureter with chromate of lead suspended in gelatine, and taking X-ray pictures of the prepared specimen. In one case the arteries were injected with red iodide of mercury in gelatine; the veins with chromate of lead; and the ureter with subnitrate of bismuth. The results obtained correspond so accurately with my own

description of ureter and vessels, appearing in this society's Transactions, and the much more exhaustively accurate descriptions of Mr. Brödel that I will only give a very brief résumé.

With regard to the pelvis the eight kidneys skiagraphed seem to indicate that the bifid pelvis is the commoner type. The upper segment of the pelvis forms in each a long narrow neck and receives two infundibula, of which the upper drains many calyces, the number of which cannot be determined by the method, and the lower infundibulum drains the two upper lateral calyces of Brödel, though they may be rather two lateral groups of calyces than single cups, as Brödel's pictures indicate.

The lower segment of the pelvis has a short wide neck, and ends usually in two infundibula, the upper draining the middle lateral calyces or group of calyces; while the lower drains directly or by minor narrow-necked funnels the lower lateral and terminal median groups of calyces.

My specimens differ from his plan in the narrowness of the pelvis and infundibula and the greater complexity of the calyces. The difference is mainly due to my specimens having been hardened in situ by arterial injection with 2 per cent. formalin before they were distended with the gelatine mass. In specimens on which I distended the pelvis before hardening the contours corresponded more closely to Brödel's plan. Kelly has pointed out the advantage of distending the pelvis with fluid injected into it by catheterization of the ureter before nephrotomy; and the comparison of my specimens and Brödel's drawings, and of my own specimens injected before and after fixation with formalin, emphasize the importance of the method.

Horizontal sections through the kidneys show in skiagraph the accuracy of Brödel's statement that the calyces of the posterior row point to a line about a centimetre and a half or two centimetres behind the convex border; those of the anterior row pointing nearly to the middle of the anterior surface.

Coming now to study the arteries, in some of the sections even the interlobular arterioles are injected, but in no case have I succeeded in injecting the vasa recta. These could undoubtedly be

easily reached, but these skiagraphs are made from ordinary dissecting-room kidneys, injected with the rest of the body, not from special injections. I hope in a future communication to show special injections which may demonstrate minutiae more successfully. For my purpose I wish only to call your attention to the grosser features. As seen in longitudinal views, the arteries divide dichotomously, and before they reach the hilum there are about six considerable trunks. One of these passes upward to surround the upper group of pyramids, one downward to surround the lower group, and the rest are so disposed that the anterior two-thirds of the kidney substance is supplied by vessels which lie in front of the pelvis and infundibula, while the posterior third is supplied by vessels usually springing from one trunk which lies behind the pelvis and infundibula. There is also a fairly definite line of demarkation between the two sets of vessels along which the posterior row of calyces may be laid open without wounding any large artery. This is a vertical line, one and one-half to two centimetres behind the convex border, the incision running in a plane through the kidney substance nearly parallel with the general plane of its posterior surface.

Certain of the plates show well the arterial arches formed near the line of junction between the cortex and bases of the pyramids, but they show also that these arches are not complete, there being no anastomosis between the vessels which form the two halves of the arch. The fact that there is no anastomoses of these vessels and that the arteries form terminal pencils or tree of the dichotomous type is well described in Quain's Anatomy, but the statement in Piersol's Histology is at least capable of other interpretation. The veins of these arches, on the other hand, anastomose freely, as shown in Brödel's dissections and my skiagraph.

While proper section of the kidney can be practiced without wounding any large artery, it is not so with the veins. The great trunks of the veins are all between the anterior group of arteries and the pelvis, but a great venous anastomosis takes place across the necks of the posterior secondary infundibula, and more than one calyx cannot be opened through a continuous incision without