the dehiscence of the coverings or capsule, the ovulum escapes into the fimbria, or falls into the peritoneal sac.

After the escape of the ovulum, the yelk-producing force is not in all cases immediately exhausted; hence the growth of the corpus luteum continues for a term whose limit is not yet known.

It is a periodical exacerbation of biotic force that matures and opens the Graafian cell. When the process of completing a germ and expelling it has been finished, the exacerbation ceases sooner or later, and a new periodical exacerbation of this strange life-force-or germ-producing force-is devoted to the maturation and spontaneous oviposit of another ovulum, and so on in succession, during the menstruating life of the woman; at every successive pairing season of birds; and at the annual rutting time of the more considerable mammals, and in all the migratory fishes at stated times.

It surprises me to see that many able and distinguished writers still cling to the antiquated notions as to the ovaric fecundation, which M. Pouchet has shown to be an impossibility. It appears to me that my view of the vitellary composition of the corpus luteum, and the mechanical result of its accumulation in effecting the oviposit, ought to be received as satisfactory rationale of the germ-depositing func tion. The fecundation of germs is a mystery which I deem beyond human cognition-and likely ever to remain so. The inquiry into the corpus luteum is far more feasible and practicable. No woman can menstruate but coincidently with, and in consequence of, the oviposit. Every oviposit is followed by a corpus luteum, which is larger or smaller, according to circumstances. Many women have scarce discernible ones after conception-others have very large ones. true and the false corpora lutea differ only in magnitude-not in their essential nature.

The

I have no doubts as to the essential identity of nature in the corpus luteum of pregnant women and that of the virgin; and am pleased to find that the author of that admirable work, "Die Geburtskunde mit einschluss der Lehre," etc. etc., Franz A. Kiewisch, entertains the same opinion. It is true that this author appears not as yet to have learned the reasons for supposing the corpus luteum to be a vitellary material, or, at least, that he has not accepted that rationale of the corpus luteum. Still, he is evidently a careful observer, as well as good thinker. He says, p. 80: "Da diese Erscheinung bei der Lehre von der Schwangerschaft erst genauer erötert werden soll, so schicke ich hier fur die Bemerkung voraus, das die Folliculareste bei jungfräulichen Individuen, obgleich sie in der Regel sehr unbeträchtlich zu sein pflegen, doch dieselbe Bedeutung haben, wie die bei schwangern

vorkommenden gelben Körpern, und dass ich in cingelnen scltenen Fällen auch bei nich geswhangerten Individuen bis zu Kirschengrosse entwickelte und gleichfalls exquisite gelbe Körper vorfand." Kiewisch says that the remains of the Graafian follicle, left after the ovulation in maidens, obey the same law that rules in the cases where conception has followed the ovulation-and where a true corpus luteum has been developed. He further says that, in some rare cases, he has found in the virgin the exquisitely characterized corpus luteum as large as a cherry.

In the first edition of this work, published in 1847, my statement of the corpus luteum stands as in the foregoing, and I have purposely left the text up to this point unchanged.

The preceding pages may show how considerable a mass is the literature of the corpus luteum, and how varying are the opinions. heretofore entertained upon the subject.

It was on the 18th December, 1846, that I read my paper on the corpus luteum, at a meeting of the American Philosophical Society, and that paper was ordered for publication in the Transactions.

Deeply convinced as I was that I had fallen on a true and demonstrable rationale of the corpus luteum, I was willing to wait for the decision of the learned as to the truth of my explanation. Some of the reviewers treated me with less than civility for my innovation; but I perceived that they had condemned me on a prima facie examination, and that their opposition depended rather upon a usual reluctance to abandon opinions already adopted, than upon any im probability of the truthfulness of my statements of the subject.

Professor Coste, whose second part of his 1st vol., on the development of organic bodies, was published in the summer of 1849, has adopted my views as to the vitellary nature of the luteal body. M. Coste regards the inner membrane of the Graafian follicles, and not the magma reticulatum lying betwixt the inner and outer cell, as the seat of the deposit. It is a matter of small moment, this, though I by no means yield my opinion on the authority of even so great a name as his.

Having sent my paper, from the American Philosophical Transactions of the year 1847, immediately upon its publication here, to M. Coste, I cannot withhold the expression of the surprise with which I find him acknowledging the receipt of it, and at the same time saying (in 1849, two years later), that I have arrived at the same conclusions with himself on this subject; that is to say, he got my paper in 1847, and, adopting my exposition, says, in 1849, that I have attained to the same views as he there so elaborately sets forth.

In order that the American Student may have an opportunity to become acquainted with M. Coste's views, I here translate from his Dev. des Corps Org., p. 251, the following passages:

"Indeed, upon examining with the microscope the texture of the internal layer of the capsule a short time before the period of its rupture, we find that, besides its abundant vascular network, it is exclusively composed of small vesicles or cells, each containing colorless molecular granules; but immediately after the dehiscence, they become so greatly developed that, when the convolutions fill up the cavity, they are found to be five or six times larger than they were at first. Hence it follows that the membrane whose wall they constitute must be proportionably thickened. It also becomes softer and more friable, because they cease to cohere so strongly as at first, while the wall itself becomes softened. This is the reason why, at a certain period, the capsular convolutions acquire an encephaloid appearance, the result of a modification both of the constituent vesicles and their contents, as I shall proceed to show. In process of time, a stage is reached in which the disunion of the vesicles is so easily to be effected, that it may be done by merely scraping the capsule, which detaches nearly the whole of them, after which nothing is left save the naked vascular branches that run along every plait. I have made this preparation in several follicles previously injected, so as to be able to see the facts in the clearest manner, as I have here described them.

"In proportion as the constituent vesicles enlarge, the contents are appreciably modified. In the cavity of each one of them is formed an innumerable quantity of molecular granules which renders them more and more opaque, and which, under the slightest pressure, pass out through the containing walls, that give way by laceration. These granules are remarkable, not only for their number, but also for the yellow tinge which slightly colors them. Now, as they are very abundant, and closely packed within the vesicles that contain them, it follows that the yellow tinge that is slight in the individual granules becomes very decided as for the whole mass of them. It appears that something takes place here like what occurs in the vitellus of the bird while taking on its yellow hue. I have, indeed, already said, while explaining the material conditions of this phenomenon, that it is produced by the crowding together of the granules with which the yelk corpuscles are gradually filled, and by the admixture of the oleaginous particles that are disseminated in it. The color of the corpus luteum seems to depend upon an analogous arrangement of the material contained in the voluminous vesicles that compose its mass," &c.

Let the Student do me the favor to compare this account by the learned Frenchman with that in the first edition of this work, and I feel sure he will do me the justice to admit the priority of my solution of this long questioned problem.

I beg leave to make one more quotation, which is from M. Coste, p. 268: "Baer first understood the mechanism by means of which the plaits and convolutions are produced. Pouchet showed how they become thickened; and I think I can establish the fact that the color of them depends exclusively on the nature of the molecular granules or the globules with which the cells that form these walls are filled, and not at all, as supposed by Raciborski and Pouchet, on an extravasation of the coloring matter of the blood. I have observed with pleasure, in a pamphlet sent to me by Dr. Meigs, that, in the last respect, that observer had come to the same conclusion as my own."!! Prof. Coste should have said that he adopts Dr. Meigs's views in this last respect.

PART II.

THE PHYSIOLOGY OF REPRODUCTION.

CHAPTER VI.

MENSTRUATION.

WOMEN are subject to a discharge of blood from the genitalia, which returns very regularly once a month. This monthly periodicity of the bleeding has given it, among various people and languages, the name of menses, menstrua, menstruation, catamenia, mois, monatliche, menstruaçion, mése, &c. Among us, it is called courses, periods, terms, monthlies, monthly sickness, unwell, times, and a variety of other names, hints, and allusions, that need not be here summed up.

The discharge is not met with in children, unmarriageable girls, or old women. It appertains to women only as long as they are capable of conceiving. They cease to be child-bearers when they lose the power of menstruation.

In this country the menstrual office usually commences in the fifteenth year of a young person's age, and continues to recur at intervals of twenty-eight days during about thirty years, these returns being prevented from taking place only by pregnancy and its conse quences, or by some disorder with which the woman may be attacked. The menstrual flowing commonly continues during three or five consecutive days, and the whole quantity of blood lost at each catamenial period is variously estimated to amount to from four to six ounces. As soon as the flowing or courses have ceased, the woman appears to be in all respects well until the time again approaches for her to be seized with the same kind of hemorrhage.

It is to be expected of every growing girl that she shall have her first change or show about the end of the fifteenth year, although it is very common to observe the first appearance of it at the end of the