of its substance to the brain and upper limbs. It is next found in the veins, and returns to the right auricle, by the route of the superior cava, which delivers it into the top of the auricle in front of Eustachi's valve, and opposite to the iter ad ventriculum dextrum, which gapes to receive and ingurgitate it. As soon as the right ventricle becomes thus filled, its contraction follows, and this black blood, or venous blood, or carboniferous blood is injected into the ductus arteriosus, which pours it into the aorta below the giving off of the left subclavian, thus precluding the possibility of its return to the brain where its carboniferous nature would make it fatal, by the superinduction of asphyxia; for asphyxia is black blood in the brain. The venous blood that has thus returned from the encephalon and arms, mixed with the aërated blood, is, by this beautiful arrangement, car ried with due precision back to the lower parts of the child's body, with a portion of the carbonated blood of the trunk and lower extremities. The umbilical arteries receive their share of this mixed blood, and deliver it to the placental tufts, whence it returns through the same round of circulation as before. By this curious machinery of the cavities and openings of the heart, there is a crossing of the currents of red and black blood in the right auricle-the red blood running horizontally across the posterior part of the auricle, behind Eustachi's valve, and the black blood falling perpendicularly downwards from the aperture of the superior cava, in front of it, into the iter ad ventriculum dextrum. Doubtless, the valve of Eustachi contributes much to the perfect operation of this mechanism, while Botalli's valve insures it.

The branchial apparatus above described suffices, in all the mammals and birds, to communicate to the constitution of the embryo the requisite amount of oxygen; but it ought to be observed that that amount is small, indeed, compared with the freeness of the endowment required for a state of respiratory existence. The embryo requires no more than what suffices to oxygenate its fluids and solids to the extent of provoking an active nutrition and imparting a power of gentle and infrequent muscular motion-for the foetus in utero may be regarded as torpid, and approaching in torpidity to the state of a hybernating animal. To cut off even this slender supply is to insure its destruction. Now, inasmuch as the placental blood, entering in at the umbilicus, passing by the ductus venosus to the inferior cava, along that tube to the auricle, and through the foramen Botalli to the left auricle, left ventricle, aorta, carotids, and vertebrals to the brain, takes the only possible route from the placenta to the brain; it is clear that, if, before the birth, the foramen ovale should be closed, no

But oxygen in the brain is
When, therefore, no oxygen

oxygen could possibly reach the brain. essential to the evolution of nerve-force. reaches the brain, the brain evolves no nerve-force, and the patient dies asphyxiated. The law, then, is that the foetus is born with an open foramen ovale, which becomes closed after birth, generally within three or four days, often in ten or twelve days, not rarely about the twentieth day, and sometimes never.

I have said that the child's foramen Botalli remains open during the whole uterine life; but the Student ought to observe that it is always covered by its valve, lying upon the left side of the septum-a valve so light and delicate as to be transparent, and so beautifully arranged as to enable it to cover the aperture in the most perfect manner. If the child should lie on its left side the weight of a drop of blood, on its right side, might lift, as a drop on its left surface might shut it down if lying on the right side. The normal direction of the current through the foramen keeps it open in the foetal heart. When, therefore, after the child is born, the two auricles act at the same time, in equal times, and with the same intensity, the valve is pressed upon the opening to cut off the foetal route, and compel the whole of the right auricular torrent to pass into the right ventricle. The first act of the diaphragm by expanding the foetal lungs opens a way by which the blood of the pulmonary ventricle may flow off through the pulmonic vessels, which they could not perfectly do before, for it is the expansion of the lungs that takes away the foetal atelectasis. If the left auricle should, after the child is born, be the strongest, the earliest, and the longest to contract, it is impossible that any black blood should come into it. If, on the other hand, the right auricle should, after the birth, contract sooner, longer, and more energetically than the left, the valve of Botalli would be lifted, and the black blood of the venous system, instead of flowing off by the pulmonary ventricle and artery to the lungs, would in part pass to the left auricle, ventricle, and aorta to inundate the neurine of the brain with its carboniferous stream, which, wholly incapable of exciting any biotic force in the brain, would end in cyanosis-asphyxia-death. When the nervous mass ceases to act, the whole constitution is dead; it always ceases to act where there is no oxygen. Where the oxygen reaches it in quantity insufficient to extricate the just amount of neurosity, the functions fail of their just force and regularity.

The Student will now understand that when the child is born at full term, its peculiarities, as to the structure of the heart, remain for some time unchanged; and he will be able to appreciate certain conditions of the neonatus dependent upon the continuance, partially, of

the foetal circulation—a circulation, in which the aëration of the blood is of so low a grade that it cannot supply the demand for the more vehement energies of the respiratory life.

Children are sometimes born dead without any known cause. It is probable that, in some of the instances, death has taken place in consequence of the too rapid progress of the development of the heart, which, hastening to reduce its foetal openings to the smallest diameter consistent with intra-uterine life, urges the reduction of the apertures beyond the legitimate bounds, and thus renders death inevitable by cutting off a part of the already scanty supply of oxygen to the neurine of the foetal brain.

If, in its gyrations within the womb, the child should enter a coil of the navel-string, and, passing through it, should thus make a knot on the cord—that knot, happening to be strongly drawn, might cause its death by hindering the complete return of the blood of the placenta. Sometimes two, or even three, such knots are found on the cord. I delivered a lady here of a very fine child which was dead-born, apparently from the closeness with which a navel-string knot was thus tied. It is true, however, that we meet with very healthy and vigorous children, notwithstanding the presence of one, or more than one of these knots on the cord, which, however, have not been tightened.

Since pressure on the cord, and obstruction of the course of the blood in it, may cut off the foetus in utero, it is evident that, where the cord prolapses in a labor, it may be fatally pinched betwixt the bony head of the infant and the osseous wall of the pelvis-nay, the resistance of the os uteri, vagina, and orificium vaginæ, may suffice fatally to compress it. Of this, however, we shall speak in another

page.

The child in utero is liable to a great variety of diseases, and to accidental monstrosities of structure that exert a very unhappy influ ence upon the labor. Thus it happens that the encephalon sometimes becomes the seat of a dropsical effusion, a deformity which renders the size of the head so vast as to make its transit through the pelvis impossible, until, by an embryulcia, the hydrencephalic fluid shall have been discharged.

In like manner, vast collections of water in the abdomen constituting ascites of the foetus may render the belly so large that the child cannot be born until it shall first have been tapped, which may be readily done with the long trocar, described by me in a future page, or by means of Holme's perforator, in cases where the signs of the death of the foetus are absolutely unmistakable.

It is proper that the Student should be here made aware that some of these great watery swellings of the belly of the foetus have, upon examination, been discovered to be cases of distended urinary bladder. The urinary bladder of the child has been known to rise as high as the scrobiculus cordis, and distend the belly like an enormous ascites, in consequence of obstruction or atresia of the urethra. The treatment of such a case, of which the diagnosis, before its delivery, is impossible, is the same as for ascites-videlicet, the paracentesis abdominis-which, reducing the swelling, allows the birth to be effected.

In addition to the cases of disproportion effected by dropsical collections, there are instances of accidental disproportion resulting from the union of two foetuses in one. The celebrated example of the Siamese twins is familiar in the United States, and it is easy to conceive that such a union could not but render difficult and preternatural a labor in which such twins should be born.

The instances of children with two heads are not rare, numerous examples of them being contained in the books. The example that has been so admirably described by M. Serres, in his Anatomie Transcendente, appears to me to be particularly worthy the Student's attention. This monster was born at Sassari, in the kingdom of Sardinia, in the year 1829. There were two heads, a double thorax, with four arms, and one abdomen with two legs. Being christened, the one on the right took the name of Rita, and the

left one that of Christina.

Rita-Christina

was brought to Paris and exhibited there, until death closed the exhibition when the monster had attained the age of eighteen months. I subjoin a figure which represents a case of double-headed foetus, born in Adams County, Penna., in 1844, under the medical care of Dr. Pfeiffer, a German physician in practice there, who brought the monster to this city. I engaged Mr. Neagle, one of our best artists, to paint a portrait of it, from which this small cut is taken, and represents it very correctly.

In this figure it is seen that the monster possessed only a right and a left arm, whereas Rita-Christina had four arms, because, in her case, the cervical, dorsal, and lumbar vertebræ were complete for each child; whereas in this sample, the cervi

cal and dorsal vertebræ only of each child were complete, while they united in a common or single lumbar spine, and one pelvis. Rita and Christina each had its own ribs, and a sternum for each, yet admitting of a single thoracic cavity for two hearts, and only two lungs. The liver was a compound of two livers; there were two stomachs, two duodenums, two jejunums, and two ilia, uniting, towards their lower extremities, into a single short ilium, inserted into a single cæcum. There was but one colon and one rectum, and one bladder of urine. The Comptes Rendus of the French Academy of Sciences for Sept. 4th, 1848, contains a description, by M. Valenciennes, of a porpoise with two heads, but having, like the child in Fig. 63, only two arms.

There is, in my collection, a specimen, consisting of two children united by the ileum intestine, which comes out from the navel of each child covered by the umbilical cord. The two cords, midway betwixt the children, merge into a single umbilical cord, inserted into one placenta. This specimen was presented to me by Dr. Clarke, of Philadelphia County. The children are separated by the omphalodymic cord about four inches; and there are two apertures in the cord, each of which is an accidental anus, from which the meconium escaped freely. There are also two apertures from which flows the urine produced by both children. There are many cases to be met with, of children with only one head, yet possessing two bodies and four legs; and some, in which the heads are united at the summit, or crown. I refer the Student to the Amer. Journal of the Med. and Phys. Sciences for July, 1855, p. 13, for a paper illustrated with engravings representing a double fœtus, presented to me by Dr. G. W. Boerstler, of Ohio. As those illustrations are copied from fine photographs by M. Root, of this city, they are to be relied on as faithful portraits.

Here is a correct portrait of a foetus that was shown to me by Dr. Rohrer, of this city, soon after its birth under his professional care. The great tumor on the vertex consisted of scalp lined with the ordinary encephalic meninges, and filled with the water of a vast dropsy of the brain. The posterior part of the parietal and occipital bones was wanting; some hairs grew on the part of the tumor near the vertex; the rest was bald. The child was in other respects well formed, and very large. The tumor was soft and fluctuating, but not reducible in size by pressure in the hands. Its greatest length was nine inches. I shall refer hereafter to this figure, to that of the double-headed monster of Dr. Pfeiffer, and to Rita-Christina, and to Dr. Boerstler's specimen, to show the necessity and nature of what is in Midwifery called Evolution of the foetus in all such cases. Obser