What the Germans call the internal migration of the ovum, and what is observed in animals where the two cornua of the uterus are separated, is questioned in the human race, although a case of Schultze seems to prove the possibility of it. This was a case of tubal pregnancy, in which the abdominal extremity of the tube developed by pregnancy was closed by adhesions. The ovum in this case seemed to have been seized by the tube of the healthy side, to have crossed the uterus, and entered the other tube by the uterine orifice, and to have been finally developed in this latter organ. The question in this case is, above all, whether the obliteration of the tube was not consecutive to the penetration of the ovum.
According to Henle, there is on the ligament that unites one of the fringes of the pavilion to the ovary, a groove covered as Waldeyer has proved) with epithelium, with vibratile cilia. The ovum follows this groove to reach the pavilion of the tube.
Whatever be the theory, when once in the pavilion, the ovum enters the canal of the tube, passes its whole length, and reaches the uterine cavity twelve or fifteen days after it has left the ovary. The movement of the cilia, may contribute to this progress, but it is greatly aided by the peristaltic contractions of the tube, contractions which have been proved to exist by Colin i.1 sheep killed during heat.
In the Graafian follicle the ovum is surrounded by the disc or cumu lus proligerous. At the moment of rupture, this cumulus proligerous is carried away with the ovum. Its cells disappear during the passage of the ovum through the first external third of the tube. They are then re placed by an albuminoid layer which surrounds the ovum during the rest of its journey through the canal of the tube. This albuminoid layer itself disappears at the uterine orifice of the tube; and the ovum, thus arriving free in the uterine cavity, either dies here when it has not been fecun-• dated, or is, on the contrary, grafted on to it when fecundation has taken place.
In general, the ovaries alternately furnish the ovum, but this is far from always being the case, for the same ovary sometimes makes several con secutive ovulations. In the human race this process of ovulation occurs about every four weeks, to finally cease only at the period of the meno pause.
Corpora Lulea.
The rupture of the vesicle of de Graaf is followed by cicatrization, and there results the corpora lutea.
These were described by FaHope, WOlcher-Coiter, Steon, and Regnier de Graaf, and studied by Malpighi, who named them the corpora lutea, and who considered them glands which secreted the ovum to protect it, and to aid its ejection. Regnier de Graaf, the elder, established that it was due to the cicatrization of the follicle, but he was wrong in making it the ex clusive result of a fecundating coition. The mere number of cicatrices on tbo same ovary prove that they could not proceed from former preg nancies. Haller, less exclusive, considered them only as the manifesta tion of sexual intercourse. In 1837, Coste showed that these corpora lutes were found on the ovaries of virgins, and that they were conse quently dependent upon the rupture of the ovisacs, and that this burst ing was independent of the act of copulation, and occurred at the time of the menses. In 1821, J. Power, and in 1826, Girdwood, suspected the relation existing between ovulation and menstruation; the latter having found on the ovary of young girls a number of cicatrices nearly equal to that of menstruation. This result was confirmed in 1834 by Robert Lee, but it was not until 1839 and 1840 that Gendrin and Negrier demonstrated that menstruation coincides with the maturation of the follicles of de Graaf, and that this maturation, is followed by the ejection of the ovum, and necessarily leads to the formation of a corpus luteum, without there having been fecundation or even copulation. Bishoff, and especially
Raciborski, confirmed this by a series of experiments. Nevertheless, the work of Costs shows that coition has a certain influence on the matura tion of the Graafian vesicles.
There is then, according to all these authors, a direct relation between menstruation and ovulation. We have already said that lately certain authors oppose this idea. We will return to this in a few moments.
It is especially a propos of the interpretation of the production of the corpora lutea, that writers disagree. Thus, according to Ntgrier, Jones, Montgomery, Paterson, Robert Lee, Barry, the coloration is due to a deposit of a yellow material between the two layers of the vesicle, a deposit preceding even the rupture of the vesicle, and which serves to repel the ovum and aid its ejection. Yet, according to Pouchet, there forms in the interior of the vesicle, and not between its membranes, a clot which becomes the active agent in the ejection of the ovum. Accord ing to Wagner, Bishoff and Coate, the formation of the corpus luteum is due to a growth and thickening of the internal layer, the clot of Pouchet existing only accidentally, and serving only to hinder the formation of the corpus luteum. (Figs. 62, 63, 64.) According to Coate, Courty, Longet, K011iker, this phenomenon takes place as follows: " When the ovum has escaped, taking with it a portion of the cellular layer in which it was imbedded, the internal layer of the Graafian vesicle, which is mucous, thick, non-retractile, and in contact with the remaining portion of that cellular layer, becomes the seat of a profound change, and this modification is manifested by a sort of hyper trophy or tumefaction, and by the distension of the vessels it contains. The external layer, on the contrary, is fibrous, elastic and connected with the stroma of the ovary. It floes not participate in this change, but it retracts. Its retraction, coincident with the tumefaction of the former, which is united to it at certain points by fibres, causes the formation of folds in the internal layer. These folds soon come into contact, and give the interior of the vesicle the appearance of the cerebral convolutions. This aspect becomes more marked when the internal layer is most swollen, and the external layer greatly retracted. Now, the corpus luteum results from this hypertrophy of the internal layer, and the re traction of the external. When the cause of so pronounced a thickening of the internal layer of the ovarian capsule is sought, it is found to be due simply to the development of the cells that compose this tissue. They increase little by little, and finally reach a diameter six or eight times as great as that which they had before rupture. The molecular granules which they contain multiply, and are converted into large globules. This individual increase of the cells necessarily produces that of the membrane which they form. The layer of cells that covers the internal layer is raised by the convolutions of the latter, but it plays a passive part, and does not participate in its hypertrophy. The tumefac tion of the layer increases till the vesicle of de Graaf is obstructed. From the thirtieth to fortieth day of pregnancy, the convolutions form straight adhesions, which efface their contour. The corpus luteum appears as a compact mass, and the tumor, which gradually increased, retrogrades.