296 GENERATION. 



greatest care. " By the side of the Graafian vesicles largely 

 developed, were found traces of ruptured vesicles ; but the 

 corpora lutea were evidently too old to be reasonably referred 

 to the last menstruation ; the Graafian vesicle, consequently, 

 had not matured, or at least had been arrested in its develop- 

 ment." 



In conclusion, remembering that coitus may hasten the 

 rupture of ripe follicles, we may quote the following as rep- 

 resenting what we know of the relations between ovulation 

 and menstruation : 



" As a summary, then, of all the facts that I have ob- 

 served, I believe it to be conclusive, that, in the human fe- 

 male, there is always, at each menstrual period, as during the 

 condition of rut in mammals, a vesicle of the ovary wliich 

 has a marked preponderance over the others ; that it sponta- 

 neously arrives at maturity, and, most generally, is ruptured 

 at some time during this period to give issue to the ovum 

 which it contains ; but there are cases, also, in which, in the 

 absence of sufficiently favorable conditions, this distended 

 vesicle cannot accomplish this end, and, as in mammals again, 

 may remain stationary or be entirely reabsorbed." J 



Passage of Ova into the Fallopian Tubes. 



The fact that the ova, in the great majority of instances, 

 pass into the Fallopian tubes, is sufficiently evident. The 

 fact, also, that ova may fall into the cavity of the peritoneum 

 is shown by the occasional occurrence of extra-uterine preg- 

 nancy, a rare accident, which shows that, in all probability, 

 the failure of unimpregnated ova to enter the tubes is excep- 

 tional. When we come, however, to the mechanism of the 

 passage of the ova into the tubes, the explanation is difficult. 



At the present time, there are two theories ; one, in which 

 it is supposed that the fimbriated extremities of the tubes, 

 at the time of rupture of the Graafian follicles, become 

 adapted to the surface of the ovaries ; and the other, that the 



1 COSTE, Developpement dcs corps orgames, Paris, 1847, tome i., p. 222. 



