tudinal groove so marks the fused bowel that the appearance of a double-barrelled gun is produced; tranverse section shows that they are divided by a membranous septum into two distinct canals, which communicate freely with each other by frequent openings in the septum; the bowel then divides into two distinct tubes, each with its own mesentery; this persists through a length equal to one-third of the whole; then they again fuse, and the doublebarrelled arrangement persists through a length somewhat greater

POUND DUODENUM.

than at the beginning; the small intestine finally becomes single, and continues thus to its junction with the large intestine, which likewise remains single to its termination; at the point of beginning of the single tube a small nipple-like diverticulum exists.

The rectum descends to the bottom of the pelvis, where it ends in a cul-de-sac.

The entire length of the small intestine is one and eighty-four hundredths metres (seventy-two and one-half inches); that of the large intestine sixty-six centimetres (twenty-six inches).

The liver, upon its surface, ap

FIGURE 3.—STOMACHS AND COM- pears to be a simple organ, but from its posterior inferior border project supernumerary lobes, the evident remains of a second liver. There is but one gall-bladder.

Genito-urinary System.-There are three kidneys—a large compound kidney lying in the mid-lumbar sulcus, and one in either lateral lumbar region.

The left kidney is greatly atrophied; the bladder is single; the genital organs single and well developed.

Nervous System.—Each head and neck, and each lateral half of the body is supplied by its own cerebro-spinal axis; along the line of fusion only is there any communication between the branches of the two axes.

Remarks. The genus dicephalus, to which this specimen belongs, is characterized by the existence of two distinct and separate heads, either equal or unequal, with various degrees of duplicity in the vertebral column. The component bodies are laterally conjoined; both of the faces look anteriorly, and usually in the same direction. Fisher states that of five hundred cases of human double monsters which are recorded, almost one-third belong to this genus; in these the female sex preponderates in the proportion of about two to one.

Viability. Apart from the accidents of birth, was this mon

ster viable? The answer to this is found in an examination of the structure of the heart and great vessels. Of the compound heart, the left mass displays all the parts of a complete heart, and the arrangement of the great vessels is normal, so that the aeration of the blood and its supply to the left child is fully provided for; the right mass is composed of but one auricle and one ventricle; the venous blood passing from the one to the other would have been at once driven on into the right aorta; no pulmonary artery exists to receive even a portion of it for transmission to the right pair of lungs, which, for purposes of aeration, would accordingly have been useless. No inosculation between any large arteries of the two systems exists to have permitted any admixture of arterial blood with the venous current of the right system. This

FIGURE 4.-ROSE-MARIE DROUIN, "THE SAINT BENOIT TWINS."

condition would have entailed immediate asphyxia upon the right child, had the monster been delivered alive; the speedy death of the left child would have followed; this specimen was not viable.

Closely related to this specimen, but illustrating a degree of fusion less extensive is the living female double monster known as the Saint Benoit twins. In this being the division extends through the thorax as far as to the abdomen; so that the thoracic organs and the upper extremities, as well as the necks and heads, are separate and distinct. During the months of December, 1878, and January and February, 1879, this being was exhibited by its parents in this city. Upon the 28th of February it completed its first year. During this time I visited it repeatedly, but met with much difficulty in any attempt at thorough examination of it from

the unreasonable fears and prejudices of the parents. I was finally successful, however, in obtaining an inspection of its whole body, and in enabling Mr. Dickinson to make the sketch which accompanies this report, and which represents well its external configuration.

The names Marie and Rose have been given to the right and left child respectively. Their patronymic is Drouin. In the Canada Medical and Surgical Journal of October, 1878, I have since found a description of these beings by Professor D. C. MacCallum, of Montreal, which, as it corresponds with my own later observation, I repeat:

Marie is more strongly developed and healthier looking than her sister Rosa, who is smaller, darker and more delicate looking. They are both bright, lively and intelligent looking children. The two bodies, from the heads as far as the abdomen, are well formed, perfectly developed, and in a state of good nutrition. The union between them commences at the lower part of the thorax of each, and from that part downwards they present the appearance of one female child; that is, there is but one abdomen with one navel, a genital fissure with the external organs of generation of the female, and two inferior extremities. The floating ribs are distinct in each, as is also the ensiform cartilage. The lateral halves of the abdomen and the inferior extremities correspond in size and development respectively to the body of the same side; and the same remark applies to the labia majora. The spinal columns are distinct and appear to meet at a pelvis common to both, although the fusion of the children commences at some distance above their junction. From near the extremity of each spine a fissure extends downwards and inwards, meeting its fellow of the opposite side at the cleft between the buttocks near the anus, including a somewhat elevated soft fleshy mass, thicker below than above. At a central point between these fissures, at a distance of two and a half inches (sixty-four millimetres) from the point where the vertebral columns meet, and three and a half inches (eighty-nine millimetres) from the anus, there projects a rudimentary limb with a very moveable attachment. This limb, which measures five inches (one hundred and twentyseven millimetres) in length, and is provided with a joint, tapers to a fine point, which is furnished with a distinct nail. It is very sensitive, and contracts strongly when slightly irritated.

The spinal, respiratory, circulatory and digestive systems of these children are quite distinct. They have each a separate diaphragm, and the abdominal muscles on each side of the mesial line, and the limbs of that side are supplied with blood by the vessels, and are under the control of the nervous system of the corresponding child. They have each a distinct stomach and an alimentary canal, which probably opens at a point close to the common anus. It would follow also that the accessory organs of the digestive systems are distinct for each child.

The two fissures behind are evidently the original clefts between the buttocks of each child, one buttock remaining in its integrity, whilst the other in a rudimentary condition is fused with that of the opposite child, forming the soft fleshy mass from the upper part of which the rudimentary limb projects.

These children are the products of a second gestation. They were born at Saint Benoit, county of Two Mountains, on the 28th of February, 1878. The mother is a fine, healthy-looking woman, aged twenty-six years. Her labor lasted seven hours, commencing at 1 A. M. and terminating at 8 A. M. One head and body were first born; this was shortly followed by the lower extremities, and immediately after the second body and head were expelled.

This being belongs to the genus dicephalus; species, tetrabrachius tripus.

The Saint Benoit twins have now survived their birth a longer period than in any other recorded instance among the three-footed, four-armed dicephalic monsters.

The case recorded by MacLaurin, in the Philosophical Transactions, London, 1723, Volume XXXII, Page 346, which lived for two months, is the next longest lived recorded.

When last examined by myself, this being (the Saint Benoit twins) had attained thirteen months of age; its vital functions were all being performed regularly and properly, and the mental development of the two parts was equal to that usual to children of its age. It apparently had as good an expectation of living to maturity as any other infant.

This being, though strictly included in the species to which I have assigned it, still, in consequence of the very rudimentary character of the third pelvic limb, approaches very closely to the species dicephalus tetrabrachius dipus, which it resembles in its high degree of viability. This rudimentary limb had not grown corresponingly with the rest of the body, and when seen by myself was but little longer than it is described to have been by Dr. MacCallum, ten months before. To this latter species belongs the widely known case, Ritta-Christina, which died at Paris,

FIGURE 5.-RITTA-CHRISTINA.

November 23, 1829, having lived eight months and eleven days. SPECIMEN II.-Order, Terata Katadidyma; Genus, dicephalus; Species, dibrachius; Variety, monauchenos.

History. This specimen of two-headed, single-necked monster, with one body and two anterior extremities, is a lamb which was born in the spring of 1874 near

FIGURE 6.-TWO-HEADED LAMB.

Plainfield, New Jersey. Having been at once discarded by its mother, it was spoon-fed for a time; it received nourishment by one mouth only, some imperfection seeming to exist in the other. It lived between two and three weeks. It was then prepared by a taxidermist, and no record made of its internal structure. It was afterwards secured by Dr. A. R. Matheson, by whom it has been presented to the museum of the society.

Description. The heads are equal and perfect, as far as external examination shows; they form an obtuse angle with each other as they spring from the single neck; the neck externally shows no evidence of duplicity, although undoubtedly there did exist some duplicity in the upper cervical vertebræ. It is to be regretted that the arrangements of the trachea and œsophagi cannot be ascertained. According to Fisher, this

FIGURE 7.-DOUBLE-FACED CHICK. (a) side view. (b) front view of the same.

is an extremely rare variety of duplex formation, so much so that only two or three examples of it have ever been recorded.

SPECIMEN III.-Order, Terata Katadidyma; Genus, diprosopus: Variety, triophthal

mus.

This specimen of doublefaced, three-eyed monster, is a small chick, the history of which is unknown. It was presented to the museum by Mr. James E. Pilcher. The accompanying figures admirably exhibit the degree of duplicity present. The angle made by the converging facial planes is very acute, so that the two bills are nearly parallel, and but little separated from each other. The median