GENERATION AND DEVELOPMENT. 241 



the result and purpose of the rupture of the follicles is the discharge of 

 the ova. 



The evidence of the periodical discharge of ova is that in most cases 

 in which signs of menstruation have been found in the uterus, follicles 

 in a state of maturity or of rupture have been seen in the ovary; and that 

 although conception is not confined to the periods of menstruation, yet 

 it is more likely to occur about a menstrual epoch than at other times. 



The exact relation between the discharge of ova and menstruation is 

 not very clear. It was generally believed that the monthly flux was the 

 result of a congestion of the uterus arising from the enlargement and 

 rupture of a Graafian follicle; but though a Graafian follicle is, as a rule, 

 ruptured at each menstrual epoch, yet several instances are recorded in 

 which menstruation has occurred where no Graafian follicle has been rup- 

 tured, and on the other hand cases are known where ova have been dis- 

 charged in amenorrhoeic women. It must therefore be admitted that 

 menstruation is not dependent on the maturation and discharge of ova. 



It was, moreover, generally understood that ova were discharged 

 toward the close or soon after the cessation of a menstrual flow. Obser- 

 vations made after death, and facts obtained by clinical investigation, how- 

 ever, do not support this view. (Reichert, J. Williams, Lowenthal.) 

 Rupture of a Graafian follicle does not happen on the same day of the 

 monthly period in all women. It may occur toward the close or soon after 

 the cessation of a flow; but only in a small minority of the subjects ex- 

 amined after death was this the case. On the other hand, in almost all 

 such subjects of which there is record, rupture of the follicle appears to 

 have taken place before the commencement of the catamenial flow. 

 Moreover, the custom of the Jews a prolific race, to whom by the Levit- 

 ical law sexual intercourse during the week following menstruation was 

 forbidden militates strongly in favor of the view that conception usually 

 occurs before and not soon after a menstrual epoch, and necessarily, 

 therefore, for the view that ova are usually discharged before the cata- 

 menial flow. This, together with the anatomical condition of the uterus 

 just before the catamenia, seem to indicate that the ovum fertilized is 

 that which is discharged in connection with the first absent, and not that 

 with the last present menstruation. (Kundrat.) 



Though menstruation does not appear to depend upon the discharge 

 of ova, yet the presence of the ovaries seems necessary for the perform- 

 ance of the function; for women do not menstruate when both ovaries 

 have been removed by operation. Some instances have been recently 

 recorded, indeed, of a sanguineous discharge, occurring periodically from 

 the vagina after both ovaries have been previously removed for disease; 

 and it has been inferred from this that menstruation is a function inde- 

 pendent of the ovary: but this evidence is not conclusive, inasmuch as it 

 is possible that portions of ovarian tissue were left after the operation. 

 VOL. II. 16. 



