THE GENERATIVE GLANDS 407 



ovaries and the development of the uterine mucosa, and not 

 solely upon the bursting of a Graafian vesicle. In the greater 

 number of instances there is, both before and during the bursting 

 of the vesicle, a determination of blood to the ovary. This is, in 

 all probability, the reason why ovulation and menstruation are 

 frequently coincident. Ovulation may take place in accordance 

 with a specific periodic cyclic process, or its occurrence may be 

 irregular; as a general rule, however, its periodicity coincides with 

 that of menstruation. 



In more than a third of instances, ovulation and menstruation 

 are not simultaneous. Ovulation may take place at any time, 

 and is not necessarily accompanied by uterine bleeding. This 

 fact makes it appear extremely probable that conception also can 

 occur at any time. 



Menstruation may take place without ovulation. At the 

 period when the ovaries undergo senile involution, they sometimes 

 contain normal Graafian follicles and corpora lutea, which seems 

 to show that the process of ovulation may outlast that of menstrua- 

 tion. 



It is evident from the above statements that Frankel's theory 

 of the dependence of menstruation upon ovulation and upon the 

 internal secretory function of the corpus luteum, is untenable. 

 As Rcgaud and Dubreuil have shown, rut in rabbits has no 

 connection with the corpus luteum. 



Frankel's further assumption that the corpus luteum regulates 

 the nutrition of the uterus from puberty to the menopause, is 

 also unfounded. This theory is based upon experiments in which 

 the destruction of the corpora lutea of rabbits was followed by 

 permanent nutritional disturbances of the uterus, similar to those 

 which follow bilateral castration. The results of exposure of the 

 ovaries to the action of the X-rays atrophy of the genitals, 

 accompanied by diminution in the size of the ovaries and dis- 

 appearance of the corpora lutea or Graafian follicles, with 

 persistence of the interstitial cells have alreadv been described, 

 and these are advanced bv Bouin, Ancel, and Villemin as further 

 evidence in favour of the internal secretory function of the corpora 

 lutea. Vet the results of both sets of experiments really only 

 prove the functional importance of the corpora lutea and the 

 Graafian follicles in the maintenance of the anatomical integrity 

 of the genital tract. Both tissues are destroyed by the action of 

 the X-rays, and the possibility of damage to the Graafian follicles 

 by cauterization of the corpora lutea cannot be excluded. Bucura's 

 experiments, however, resulted in negative findings with regard 

 to the corpora lutea. These experiments proved that atrophy 

 after castration may be prevented by the transplantation of the 

 ovary from an animal of another species, provided that the ovary 

 contains developing Graafian follicles, the presence of an intact 

 corpus luteum being alone insufficient to affect the result. That 



