It is said to have been aborted in the fifth month of pregnancy; yet the embryo that can lodge within so narrow a chamber can scarcely have more than a few weeks’ growth. It is in Sir Charles Clarke’s collection, and I am indebted to Mr. Stone for permission to have it drawn by Mr. Perry, with three or four more specimens contained in the present publication.
On the right of the drawing, the real extent of the thickening of the external covering is not sufficiently denoted. There are in the substance of
REMARKS.
Calculous, steatomatous, and solid placentas are not of unfrequent occurrence in practice. I have seen several such cases. Sir Wm. Blizard presented to the Royal College of Surgeons a very instructive specimen of a human Ovum having a sarcomatous and calculous placenta, which had been expelled at three months and a half, by a patient who had miscarried three times within the three previous months.
There is also in the same college a magnificent specimen of a solid Ovum, of the size of a hen’s egg and shape. A small portion of the shell of this Ovum having been cut off, the embryo is seen, of the size of a common fly, within the cavity, which may be just large enough to admit the top of a man’s thumb. The ordinary involucra are so compact, and so firmly adhesive to one another, that they cannot be separately distinguished. The parietes thus formed are at least one fourth of an inch in thickness. On the right of the inside of the cavity there is seen a large swelling, which projects within the said cavity, and is probably the receptacle of another embryo, or a deposition of blood between what ought to be the translucid membranes or involucra.
Sometimes the fœtus alone has been found to have become an in-formed, hardened, or steatomatous mass. This is the case with a preparation, a striking one, in the Museum of St. George’s Hospital, midwifery division, marked F. 94. The fœtus, two inches long and perhaps one inch in diameter, is converted into a solid mass, retaining barely the outline of some parts of its form, with the exception of the vertex of the head, which is clearly defined. The mass appears to be steatomatous, and is suspended at a point considerably below the centre, by a regular umbilical cord pending from a large placenta, having the transparent and other involucra, which are laid open for inspection. A minute dissection of these various parts could not fail to throw considerable light on many important points connected with the diseases of the human Ovum, the fœtus, and its structure. At present the preparation is only imperfectly instructive.
Fig. 22. Ovum cum involucris internis, ab amnionitide et chorionitide, condensatis.
(Gestation, near upon five months?)
Here we have a specimen which will embarrass not a little those writers in obstetrics who, either through respect for olden authorities, or from habit, keep repeating what has been said before them, respecting the structure of the human ovum. I will describe the ovum as it stands before me this day, the 21st of January, 1833, on which occasion I again compared it with the drawing made some years before, and found the latter most strikingly correct in all its parts.
Beginning externally, we find a thin pellicle, many fragments of which are seen floating, covering the whole of the placenta, which seems consolidated and to have been compressed. These parts are not visible in the figure here represented, as they are placed at the posterior portion of the specimen. From each side of, and at the edge of the placental cake, comes a loosely-webbed, semi-transparent, coarse membrane, in some parts porous, in other parts opaque, which proceeds from under the placenta, and must have embraced the entire ovum before it was laid open. This membrane resembles that called the caducous,—and is in fact the membrane marked as such in all the preparations of human Ova in most obstetrical collections. Within this membrane we find another, considerably thickened, which, judging from the several portions that remain yet transparent, is actually passing from the latter into the opaque state: it is bifoliated. Immediately within the last-described envelope, and at the inferior part of the Ovum, we observe a thick cake, which was probably extravasated blood: it extends upwards on the right of the observer, getting less thick as it proceeds. The cake itself, on the side next to the fœtus, is lined, but loosely, by another bifoliated transparent involucrum, held fast to the involucrum just described by filiform vessels, which in some parts are distinctly visible even to the length of half an inch, with a space of the same dimension between the membrane and the cake before mentioned. The inside lining of the whole is the amnion, from the upper and lateral portion of which hangs an umbilical cord of three quarters of an inch in length, with an imperfect fœtus the size of half a wasp, in which however the rudiments of the abdominal extremities are quite distinct. The whole Ovum measures four inches vertically, and three inches transversally.