572 OVULATION AND FUNCTION OF MENSTRUATION. 



rusty tinge, until it finally disappears altogether, and the female 

 returns to her ordinary condition. 



The menstrual epochs of the human female correspond with the 

 periods of oestruation in the lower animals. Their general resem- 

 blance to these periods is too evident to require demonstration. 

 Like them, they are absent in the immature female; and begin 

 to take place only at the period 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 

 interruption by pregnancy and lactation. Finally, their disappear- 

 ance corresponds with the cessation of fertility. 



The periods of cestruation, furthermore, in many of the lower 

 animals, are accompanied, as we have already seen, with an unusual 

 discharge from the generative passages ; and this discharge is fre- 

 quently more or less tinged with blood. In the human female the 

 bloody discharge is more abundant than in other instances, but it 

 is evidently a phenomenon differing only in degree from that which 

 shows itself in many species of animals. 



The most complete evidence, however, that the period of men- 

 struation is in reality that of ovulation, is derived from the results 

 of direct observation. A sufficient number of instances have now 

 been observed to show that at the menstrual epoch a Graafian 

 vesicle becomes enlarged, ruptures, and discharges its egg. Cruik- 

 shank 1 noticed such a case so long ago as 1797. Negrier 2 relates 

 two instances, communicated to him by Dr. Ollivier d'Angers, in 

 which, after sudden death during menstruation, a bloody and rup- 

 tured Graafian vesicle was found in the ovary. Bischoff 3 speaks of 

 four similar cases in his own observation, in three of which the 

 vesicle was just ruptured, and in the fourth distended, prominent, 

 and ready to burst. Coste 4 has met with several of the same kind. 

 Dr. Michel 5 found a vesicle ruptured and filled with blood in a 

 woman who was executed for murder while the menses were pre- 

 sent. We have also" met with the same appearances in a case of 

 death from acute disease, on the second day of menstruation. 



1 London Philosophical Transactions, 1797, p. 135. 



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



3 Aunales des Sciences Naturelles, August, 1844. 



4 Histoire du Developpement des Corps Organises, Paris, 1847, vol. i. p. 221. 



5 Am. Journ. Med. Sci., July, 1848. 



6 Corpus Luteum of Menstruation and Pregnancy, in Transactions of American 

 Medical Association, Philadelphia, 1851. 



