Finally, Duchamp, in 1880, returning to Robin's view, considers fatty degeneration secondary to fibrous degeneration.
From an examination of these different opinions we conclude that the subject of placental lesions may be summed up thus: 1. Hemorrhages occur in the placental tissue, and the extravasated blood undergoes great change; 2. The villi may undergo a fibro-fatty degeneration; 3. There may be, simultaneously, extravasation and degeneration of the villi.
But the questions already asked by us, in our thesis of 1869, now pres ent themselves again, viz.: 1. May there be placental hemorrhage or thrombosis without change in the villi ? 2. May there, conversely, be changes in the villi withoust hemorrhage or thrombosis? 3. In mixed cases, with both lesions, are they dependent upon each other, and which is the initial li3sion? The facts reported by Hiffelsheim, Laboulbene, Depaul, Ercolani and de Sin6ty show that the first question may be answered affirmatively. The same is true of the second question, as is proved by the cases of Robin and of Depaul and de Sinky.
The solution of the third problem is far harder. Less positive than formerly, we no longer say, as in 1869, that the lesion is one. There is, first, fatty degeneration and obliteration of the villi, and then extravasation of blood which undergoes transformations; these two lesions being, in re,ality, successive degrees of one and the same change in the placenta. We do not, however, adopt the exaggerated ideas of Bustamente. His anatomical considerations on the structure of the villi are not conclusive. Indeed, the researches of the Germans and of Dastre tend to show that the villus is not hollow, as Robin thinks, but formed, externally, by a layer of polyhedral epithelial cells enclosing fatty globules and crystalline rings, or rods beneath this layer, and by a parenchyma of connective tis sue arranged in planes parallel to the surface and forming a more or less dense felt-like tissue. Stellate cells are interposed between the groups of fibres. The villus is formed by a displacement of the chorion when the vessels enter, but no central canal is formed. At the point where the displacement of the chorion is to occur, the fibres of connective tissue. parallel to the surface, become erect to enter the villi, the centre of which they form.
There is, here, nothing comparable to what Ch. Robin understands by the fibrous degeneration of the villi, which is a well-ascertained lesion.
Besides, if, at the beginning of pregnancy, the extravasation of blood can only come from the maternal circulation, it may, later, come from the umbilical vessels. Millet expressed this opinion and certain microscopists have seen aneurisms on the umbilical vessels, near their entrance to the pla centa, the rupture of which would explain the apoplectic extravasations. The facts quoted by Cauwenberghe, himself, and by liegar and Maier prove the changes in the umbilical vessels. We reserve our decision, for both explanations can be maintained while neither is absolutely proven. This is, moreover, Duchamp's opinion.
IV . Calcareous Changes in the Villi.
By the terms ossification, ossiform concretions, placental calculi and calcareous degeneration, authors understand deposits of lime, either on the surface or in the interior of the placenta. Sometimes there are iso lated grains or needles, sometimes calcareous masses. The grains contain amorphous carbonates and phosphates of lime and magnesia, and are found, most frequently, on the uterine placental surface. Carestia has reported some on the foetal surface. Lobstein, Meckel, Adelon and Cru veilhier, thought that they were in the capillaries. Robin has shown that the grains are especially found in the cotyledons whose villi are wholly or partly obliterated. They adhere, strongly, to the surface of the villi, surrounding and sometimes obscuring the villi, always deforming them. They are, then, in the maternal placenta, 113 Ercolani also believes.
causes of the changes of the placenta mostly elude us. Ilegar has observed, in a great number of ova, coexistent anomalies of the decidua and of the embryo which we have mentioned before, and this may explain the abortions occurring in the first months. This is not true of the important placental lesions which we have just considered. The advocates of the theory of blood changes have sought the explana tion of these phenomena in placental thrombosis. But what are the causes of this thrombosis? Cauwenberghe finds them in the conditions of th8 placental circulation, the modifications of which seem to tend to one and the same end, viz., augmentation of the quantity of blood, and ex cessive slowing of the circulatory current, or changes in the composition of the blood.