viscera, with one exception; 5, one common umbilical vein; 6, one liver, with a double circulation; 7, the curve of the inferior cava of the right fœtus to the left side of the vertebral column; 8, the radical change in the relations of the vena cavas, hepatic veins and venous ducts. to the posterior border of the liver; 9, the duplication of all the organs (liver excepted) as represented in plate 5.*

The physiological questions may be very briefly considered in two relations: first, through the common liver and, second, through the connecting soft tissues. In the liver terminate the peripheral extremities of a portion of the two great nervous systems; the cerebro-spinal axes, connecting its animal sympathies with the cerebrums through some filaments derived from the pneumogastric and right phrenic nerves. The ganglionic systems connecting intimately and inseparably, the organic functions through the hepatic plexuses derived from the solar plexuses of two beings. We have in the nerves, a union of sympathy and organic function. The complicated

#PLATE No. 5.—R, right, L, left foetus; C, common liver; E E, right and left extremities of the liver; U, umbilical vein; D, common diaphragm; S, stomach and duodenum; v v, inferior or ascending venæ cavæ; m, superior mesenteric vein entering the under-surface of the right extremity of the liver; S', spleen; a, splenic artery; x, splenic vein; y, superior mesenteric artery distributed to a portion of jejunum j; kˇk, kidneys, the right kidney of the left fœtus having the capsule removed to show the lobulated structure, renal artery and vein, and the left kidney surmounted by the supra renal capsule; ii, common iliac arteries diverging from abdominal aortas, also showing the four hypogastric arteries tied to the end of the cord U; u', ureters of the left foetus; B B, the bladders, showing in each the urachus projecting from the apex; t, gubernaculum testis; F, sigmoid flexure of the colon inflated and turned back; H, heart of the left foetus, on either side of which the lungs are seen; P, pulmonary artery; A, aorta with ductus arteriosus concealed; O, superior or descending cava formed by the union of the right and left venæ innominatæ seen above; they again each formed above by the internal jugular and subclavian veins; e, common carotid arteries of the left foetus; n n, right and left pneumogastric nerves; w, trachea; H', heart of the right foetus enveloped in its pericardium, the latter attached to the diaphragm; the lungs are shown on either side; O', superior or descending cava of the right foetus, formed by the junction of the brachio-cephalic veins; I, arteria innominata dividing into the right common carotid and subclavian arteries; 1, left subclavian vein; l', left internal jugular vein; T, thymus gland; r, thyroid body; z, larynx.

structure of the orgau fits it for its great function, the distillation of the bile, a constant secretion in greater or less quantities; and constantly delivered from this common source to two digestive apparatuses.

This fluid, complex in its chemical composition, is not a mere excretion as some maintain; but it is a necessity to nutrition and life, as proved by experiments on dogs in which death soon followed the absence of bile in the intestinal canal. Two lymphatic systems also act their part in the hidden mysteries which govern the laws of health. In short, this singie organ performs all the important physiological functions connected with the liver for two individuals.

The physiological union through the soft tissues of the connecting band are of minor importance, being limited to the capillary inosculations of the sanguineous and lymphatic systems, and the intermingling of the sensor and motor nerves for a short distance on either side of median line. The healthy relations of the two then are common, derived from the same fountain head and disturbed by the same causes.

In their pathological relations any symptomatic, disease of the liver, whether functional or organic, would necessarily affect both alike. Functional disorders of any of the duplicated organs, as the brain, lungs, heart, etc., of one would not disturb necessarily the health of the other twin. Local inflammations in one, as pneumonia, nephritis, dysentery, &c., would not be developed in the corresponding organs of the other, but he would only suffer from the symptomatic fever communicated through the circulation. Idiopathic disease, as typhoid fever, and zymotic disease, as small-pox, rubeola, poison, &c., would affect both simultaneously through the vascular and lymphatic connections. The administration of all remedies, acting through the systemic circulation, would influ

ence both alike in consequence of the two capillary anastomoses-first, and most important, in the liver, and, second, in the connecting band.

The Obstetrical Relations.-The frequency with which monster births have occurred in all ages and all countries, as evinced by the number of cases found in medical museums, private offices, and reported in the medical journals every year, attaches great and special importance to this part of the subject. These births are not premature, as is generally supposed; but they come at full term like ordinary confinements, without any premonition of the complication. In the following reported cases, only one was said to be premature and this one only twenty days before the time. Such a birth may occur under the supervision of any practitioner, the proper obstetric management of which, in many instances, involves the life and future health of the mother and the life of the two unfortunate twins. In this embarrassing perplexity the impulse of the moment is not always a correct index to the proper treatment necessary to be instituted. One rash, inconsiderate step will jeopardise the life of three human beings. The hopes of the mother and friends are concentrated in the adjudged superior skill and wisdom of the attendant physician. What landmarks, then, have we from past experience?

W. S. Playfair, M.D., selects from Dr. Allan Thompson's classes four varieties which interest the obstetrician:*

First. Two nearly separate bodies united in front to a varying extent by the thorax or abdomen.

Second. Two nearly separate bodies united back to back by the sacrum and lower part of the spinal col

umn.

*See Obstetrical Transactions, VIII.

Third. Dicephalous monsters, the bodies being single below but the heads separate.

Fourth. Bodies separate below, but the heads fixed or partially united.

Dr. Playfair has collected 31 cases belonging to these four classes, which present the following ratio of frequency: First class, 19; second class, 3; third class, 7; fourth class, 2. It will be observed, as a point of professional interest, that a fraction over three-fifths of the whole number belong to the first class.

Of the thirty-one births, twelve were delivered by natural powers and without difficulty. How fortunate that nature is so provident and sumptuous in her resources, to overcome obstacles.

In the nineteen cases belonging to the first class, to which, also, belongs the pair presented in this paper, and the Siamese twins now living, of whose birth no account has ever been given, the labors resulted as follows: "One (mother) died undelivered; eight were terminated by natural powers, in three of which the feet and in three the head presented; in two the presentation is doubtful; six were delivered by turning, or by traction on the lower extremities; four were delivered instrumentally."

In the three feet presentations, delivered by natural powers, the best account is given by Fanzango, of joined twins, born alive at Camignore, November 6, 1602, who lived a number of years and were exhibited in Italy. The bodies were only united by the upper part of the abdominal walls. Fanzango remarks:* "It was a happy circumstance for the mother that she was not under the charge of a practitioner with his head full of the doctrines of the surgeons on this subject, otherwise he probably would have performed some severe and dangerous

*See Obstetrical Transactions, VIII.