These facts show that menstruation and ovulation proceed pari passu ; but they do not alone prove that the one function is dependent upon the other.
lf, however, both ovaries are congenitally deficient, no attempt at menstruation is ever observed; while, on the other hand, in cases where the ovaries are present but the uterus is deficient, puberty becomes established in due course, and then a regularly- recurring menstrual molimen may be observed, although for the N‘ant of the uterus this function can not be carried out. See note §.
Or if, under ordinary circumstances, after the regular establishment of menstruation, both ovaries become extensively diseased, or both are removed by operation-I-, menstruation is from that moment permanently suspended.
Hence it appears that the presence of the ovary in a healthy state is essential to men struation.
But something more also is needed ; for the ovaries may be present and healthy, yet if they cease for a time to mature or emit ova, as for example during pregnancy and lactation, when they are passive t, then, so long as those processes endure, menstruation is also com monly suspended, but returns after the com pletion of one or both of them.
A series of facts so consistent appears to admit of but one interpretation : namely, that a menstruating condition of the uterus bears a direct relation to the active operations of the ovaries, and that this function is only per formed under circumstances which render pregnancy possible so far as the ovaries are concerned ; but if the conditions are such that impregnation cannot take place, then the ute rus, although it may be healthy, does not menstruate.
But, in addition to this general relationship between menstruation and ovulation, it is ne cessary to determine further if any direct cor respondence exists between each separate act of menstruation and the maturation or dis charge of one or more ova from the ovary, so that these two acts shall be coincidentally performed.
The following evidence supports this view.
The ovaries at the menstrual periods are not unfrequently the seat of pain and tender ness, indicating some unusual activity of this part. This is most remarkable in the rare case of hernia of the ovary.§ In women who have died during a men strual period the ovaries have been frequently observed to present unmistakable signs of the recent rupture of one or more Graafian fol licles. Some examples of this fact have been
already given. one case the ovum itself was found in the Fallopian tube (p. 567.).* Conception is supposed to take place most frequently within a few days after a menstrual period, and therefore during the time la hich an ovum, if it were emitted from the ovary during menstruation, would occupy in passing down the Fallopian tube and perhaps in ar riving at the uterus.
Menstruation corresponds in many particu lars with the cestrus, or rut, in the niammalia, and in them it is only during the cestrus that ova are emitted from the ovaries, and that con ception can take place.
The foregoing facts constitute evidence bearing upon two distinct points. The first series proving that a menstruating condition of the uterus is maintained only so long as the ovaries continue in the active performance of their function of preparing and ripening ova. The second series affording a certain amount of presumptive evidence, that each separate act of menstruation is connected with or is dependent upon a corresponding act of maturation, and perhaps of spontaneous emission of one or more ova from the ovaries.
The accuracy of the first conclusion will probably not be questioned ; but if the second point is to be regarded, as at present, more than an hypothesis having many facts and probabilities for its support ; if, as M. Pouchet believes, we are justified in considering as established laws 'of generation that in man ova are emitted from the ovary at fixed epochs and at no other times, and that these occa sions, which furnish the sole opportunities for impregnation, bear ihe same constant relation to menstruation that the acts of ovulation and the times of conception in the mammalia bear to the cestrus, it becomes necessary to exa mine more closely the grounds of this belief ; and for this purpose the circumstances as yet ascertained regarding the times of conception in women, the condition of their ovaries, not only during menstruation but in the intervals also, and the actual relation which the cestrus, or period of conception in mammals, bears to menstruation, may be briefly passed in review.