OVULATION AND MENSTRUATION. 605 



ish or rusty, until it finally disappears, and the process comes to an 

 end. 



The menstrual periods of the human female correspond with those 

 of oestruation in animals. Like them, they are absent in the immature 

 condition, and begin only at the time of puberty, when the aptitude 

 for impregnation commences. Like them, they recur during the child- 

 bearing period at regular intervals, and are liable to the same inter- 

 ruption by pregnancy. Finally, their disappearance corresponds with 

 the cessation of fertility. 



The periods of restruation, in many animals, are accompanied with 

 an unusual discharge from the generative passages, frequently more 

 or less tinged with blood. In the human female the bloody discharge, 

 though more abundant, differs only in degree from that which exists 

 in other instances. 



But the most complete evidence that the menstrual periods coincide 

 with ovulation, is derived from direct observation. A sufficient num- 

 ber of instances have been recorded to show that at the time of men- 

 struation a Graafian follicle becomes enlarged, ruptures, and discharges 

 its egg. Cruikshank* noticed such a case in 1797. Xe'grierf relates 

 t\vo instances in which, after sudden death during menstruation, a 

 bloody and ruptured Graafian follicle was found in the ovary. Bis- 

 choffj speaks of four similar cases, in three of which the follicle was 

 just ruptured, and in the fourth distended, prominent, and ready to 

 burst. Coste met with several of the same kind. Michel || found a 

 follicle ruptured and filled with blood in a woman who was executed 

 for murder while the menses were present. Two instances are reported 

 by Letheby,*" in one of which he succeeded in finding the ovum in the 

 corresponding Fallopian tube. We have also met with two instances 

 of Graafian follicles freshly ruptured and filled with blood, in women 

 who died during or immediately after menstruation. 



Ovulation, accordingly, in the human female, accompanies and forms 

 a part of menstruation. As the menstrual period comes on, a congestion 

 takes place throughout the generative apparatus ; in the Fallopian tubes 

 and the uterus, as well as in the ovaries and their contents. One of the 

 Graafian follicles is especially the seat of vascular excitement. It be- 

 comes distended by the accumulation of fluid in its cavity, projects from 

 the surface of the ovary, and is finally ruptured ; the process taking 

 place essentially as in mammalian animals. 



It is not certain at what precise time during the menstrual flow the 

 rupture of the follicle takes place. According to Bischoff, Pouchet, and 

 Raciborski, it usually happens, not at the commencement, but toward 



* Philosophical Transactions. London. 1797, p. 135. 



f Recherches sur les Ovaires. Paris. 1840, p. 78. 



| Annales des Sciences Xaturelles. Paris, Aout, 1844. 



"i Histoire du Developpment des Corps Organises. Paris, 1847, tome i., p. 221. 



|| American Journal of the Medical Sciences. Philadelphia, July, 1848. 



r Philosophical Transactions. London, 1852, p. 57. 



