Etiology. Congestion is a sufficient agent as an excit ing cause; but it is fair to presume that there must exist certain predispositions, or the accident would be even more frequent than it is. With every menstrual nisus there is marked congestion of all the genital organs, the placenta, of course, included; but hemorrhage does not by any means exist in all placenta. Robin has described a fibrinous obliteration of the calibre of the vessels, with consecutive hemorrhage, and this is the doctrine most accepted in France. Latour (1843) regarded the compression of the hypogastric and iliac arteries by the pregnant womb as the primary cause of apoplexy, while Verdier denotes an arteriitis of the vessels as the first condition of departure. According to Hegar, atrophy or hypertrophy of either the foetal or maternal placenta, increased development of the glandular element, abnormal insertion of the allantois and umbilical vessels are all sufficient as predisposing causes, which congestion, "the stroke-giving cause,' completes. Other indirect causes, as fatty degeneration, &c., will be mentioned under these heads respectively. It is proper to state, however, that some pathologists regard all the degenerations, fatty, fibrous, calcareous, purulent, as only results of extravasations, and occurring in the retrograde metamorphosis of the effused blood. This would simplify and contract the domain of placental pathology most materially, if true, but the doctrine is not by any means one of universal acceptance.

Transformations. The coagulum once formed may undergo resolution, or it may condense and remain permanently. Simpson regards all the small yellow spots

or masses upon the surface of the maternal placenta as so many extravasations in retrograde metamorphosis. The altered fibrin of the blood gives the tissue its consistence, and its partial change afterwards into fat, its color. Salts of lime are deposited in abundance at this time, and this furnishes the roughened surface to touch. It is exceedingly questionable whether the mass ever becomes organized to permit a return of circulation. Robin declares the coagulum a foreign body incapable of organization. A clot may very often be recognized and differentiated from a mass of fatty or fibroid degeneration by a section through its centre. A coagulum is distinguished by presenting superposed layers or segments, as in an aneurism or in the onion. This condition seems to be due to the fact that the blood of its mass is extravasated at different times, and at such intervals as to permit the preceding effusion to coagulate and condense. A small quantity of nearly liquid matter exists generally in the centre, due to subsequent softening.

PLACENTITIS.

Almost all the older writers describe inflammation of the placenta as one of possible though rare occurrence. Its first mention is by Guillemeau, in his "Euvres de Chirurgie," 1648. Brachet, in 1828, fully described the condition of hepatization, which he considered one of the stages of inflammation. It was recognized also by Desormeaux and Paul Dubois. Stratford published a case in the London Med. and Surg. Journal, Jan., 1829.

Dance, 1829, detailed a case with comments in the Arch. Gén. de Méd., vol. xxi., p. 222. Simpson positively af firms its existence in the Edinburgh Med. and Surg. Journal, 1836. Geoffroy reiterates the opinion of Mat tei in 1858. Joulin speaks of it in 1867, and references, longer or shorter, may be found in many modern works on obstetrics, particularly the Continental; and Klob (loc. cit., p. 522) quotes besides an array of German and French pathologists on this subject. A great number of equally eminent names might be cited, however, who assign it no place in nosology. Tarnier is silent on this subject. Verdier denies its existence, attributing the phenomena ascribed to it to retrograde metamorphoses of blood-clots, in which Bustamente coincides. Mayer explains the appearances resembling it by a hyperplasia of connective tissue and fatty degeneration. Millet* says of it: "Nothing is less precise than the symptoma tology of this affection; nothing is less exact than its pathological anatomy; nothing, in a word, is less proven than this inflammation itself;" and Charpentier,† from whom many of these facts of its history are abstracted, is doubtful of its existence. Robin finally attributes its phenomena to the "fibrous obliteration of the vessels" to be fully described. Brachet, who really merits the credit of its first full and scientific description, published four cases in the Revue Médicale of Lyons, of which the fol lowing is a condensed abstract. The first was a case of twins, one child living, one dead. "One of the placenta was livid, voluminous, more compact in tissue

* Thèse sur le Placenta, 1861.

+ Maladies du Placenta, etc. Paris, 1869.

and less yielding to pressure, though more friable. At the first glance it presented the aspect of the red hepatization of the lungs." He considered this condition as causative of the death of the foetus, and from its analogy to that stage of pneumonia in the lungs he named it red hepatization of the placenta. In a second case of dead foetus he encountered a placenta "less voluminous, its foetal surface smooth and of a rich gray color, the tissue firm but fatty in of its substance, the other being normal." In a third case the foetus was born liv ing, but died in 20 hours. The placenta, which required some time in its detachment, was "normal in half its substance, while the other half was dense, friable, and engorged with black blood, presenting in a word the lesion proper to placental inflammation." In the fourth observation there was a threatened abortion from copious hemorrhage during pregnancy; accouchement at term, infant living but feeble. "The placenta was thick, more consistent in one half than the other; the more consistent portion being dense, homogeneous, yel lowish, strewn with points of fatty degeneration, and analogous to that condition of the liver known as fatty degeneration; the other portion was normal." Brachet cites further several cases in which the inflammatory process proceeded further and terminated in suppuration, the various stages exactly simulating those in the lung; congestion, red hepatization, gray hepatization and suppuration. (See abscess.) The terminations of placental inflammation are: 1. Induration (hepatization), the condition described by Brachet, marked by reddish or yellowish (according to the predominance of

blood or fat) more or less solid masses, presenting a decided analogy to the fibrous metamorphoses of bloodclots, but not possessing the tunicated arrangement, to use a botanical phrase, on section. 2. Exudations of a plastic nature from an exuberation of connective tissue, with adhesion to the uterine wall.* 3. Suppuration. Phthisis placenta in the form of circumscribed ab scesses, as occurs in inflammation of other parenchymatous organs. Dance and Breschet have seen a deposition of pus covering the entire surface of the placenta, and Dance has further reported a case wherein pus was poured out between the amnion and chorion; the chorion being opaque and thickened. Jacquemier has observed pus infiltrated throughout the parenchyma, and all the writers mentioned, with Cruveilhier, have reported cases of abscess.

Sclerosis.

Neumann calls attention also to a sclerosis as a fourth termination of inflammation, a condition in

*This adhesion has been claimed as an extension of an endometritis. It is impossible to state, in those cases where an endometritis has been demonstrated to coexist, which was the primary lesion. The fact that pressure upon a certain portion of the abdomen after delivery in these cases elicits a circumscribed, fixed, and burning pain, which is attended with a light febrile condition. speaks strongly in favor of their coincidence. That the pain of pressure during pregnancy does not depend upon a placentitis is proven by the fact that there is no nerve-communication between the placenta and uterus.

Braun (Lehrbuch der Geburtshülfe) finds a cause of hydrometra gravidi uteri in the fluid poured out by this inflammatory process, or by an existing endometritis serosa. The nearer the collection is to the os uteri the sooner will it be discharged. Wedl, who had an opportunity of examining a placenta in such a case, found a neoplasm on the convex surface, which consisted under the microscope of a delicate fibrous tissue. Nonat and Linas agree with Stoltz and Naegele in considering hydrometra a condition peculiar to pregnancy, and due, like mole, to some process of degeneration. Maladies de l'utérus. 1869, p. 485.