In the knowledge of the doctrine of abortion and the treatment of it, a preparation like the present is of infinite value. But this is not the place to enter into practical views and details which are reserved for my professed work on that subject.
I saw, on the 29th of May, 1828, in Sir Charles Clarke’s collection, which was then in Mr. Stone’s possession, a specimen of tuberculated placenta, larger than, yet in other respects similar to, my own. The fœtus, however, was not of greater dimensions than the one in the present figure. In the same collection there were two smaller specimens of this identical disease of the human Ovum, very neatly put up, one of which, like my own case, exhibits most distinctly the injected state of the amnionic vessels. It was stated on the label of the largest specimen, that the growth of the child had been impeded by the pressure of the tubercles on the cord. This is not apparent on examination of the preparation. The cause of that impediment is manifestly the defective structure of the placenta.
The College of Surgeons possesses two specimens of tuberculated placenta. One is small, marked 3443, (old series,) and placed in the Gallery; the other, a very large specimen, is among the morbid preparations in the body of the Museum, No. 983. (old series). The latter was presented by Sir E. Home, who has entitled it a case of Cysts of the Amnion. On close examination it will be found that these pretended cysts (or, as he has called them afterwards in a printed paper, hydatids) are nothing more than elevations of the amnion, beautifully exhibiting the vessels of that membrane, elevations which are produced by no other process than the one described below.
No. 3447 in the same Museum, demonstrates by another fact and process the vascularity of the amnion. The case is one of twins, aborted at about two months and a half. The fœtus in the one cavity is as fully and properly developed as that in the other, and they are separated by a translucid septum, formed by two layers of the amnion. Into this septum, and not into the placental cake, terminates the cord of one of the fœtuses, expanding itself on its surface; while the cord of the other proceeds regularly to the placenta. It is manifest, therefore, that the vessels of the amnion must have carried blood to the umbilical vessels in the one fœtus, as he was not in direct communication with the placenta.
The preparation before alluded to, as being in the collection of the Royal College of Physicians, marked 7 G. 19, is another excellent specimen of tubercular amnion. Denman has given us a very striking example of this same diseased structure of the Ovum, which I strongly suspect, must be a delineation of the largest specimen in Sir Charles Clarke’s collection mentioned before. The fœtus, like the one in the present plate, is small, and the cord inflated, but the entire Ovum remained in the womb until the completion of the ninth month.
All the tubercles of placentas which I have seen, were on the fœtal and not on the uterine side of the membranes. They seem to be formed by the enlargement of those filiform vessels which exist on the inside of the same involucrum, (Chorion,) the outer surface of which bears the mossy or filiform vessels, destined to group themselves into cotyledons for the purpose of forming the placenta. When the Ovum, after having lived and grown on its own life-principle, through its journey from the Ovarian nest into the cavity of the womb, has accomplished that connexion with the mother which before did not exist, the filiform vessels on the inner surface of the membrane in question, ought forthwith to begin to wither and be absorbed. When this is not the case, and they on the contrary enlarge, tubercles are formed, which are nothing else than cotyledons, or groups or tufts of vessels, like those on the external surface, and which push the innermost membranes, the amnion in particular, forward, and give rise to congestion and diffusion of blood.
Ruysch, who has published some engravings of this structural deviation in the human Ovum, has accompanied them with an explanation of its causes.
Fig. 21. Ovum pene-solidum; placenta sarcomatosa cum tuberculis hœmatosis; involucra fœtûs solidificata.
(Gestation four months and a half?)
What havoc has disease effected in this Ovum! Scarcely can we recognize a single element of its structure. The placental covering is composed of many substances, has lost its spongy vascularity—it has acquired several solid tumours, and is altogether unfit for its intended function. The cortex of the Ovum is fleshy; but within it a supernumerary fine membrane is seen, which might, but must not, be mistaken for the chorion. The latter involucrum, and the rest of the membranes within it, have become compact, they adhere together, and form a solid whole, which has scarcely the appearance of what it is—a human Ovum.