406 INTERNAL SECRETION 



Frankel, supplied the incentive to extensive experimental and 

 morphological investigation, which produced no actual confirma- 

 tion of the theory, but which supplied valuable information con- 

 cerning the sites of origin of the ovarian hormones. 



The point in regard to which the least confirmatory evidence 

 is forthcoming, is Frankel's theory that the originating cause of 

 menstruation is to be sought in the corpus luteum. A small 

 number of findings have been described (Magnus, Lindenthal) 

 which seem to point to such origin ; but the value of Frankel's 

 cautery experiments is disputed by the majority of authors, who 

 bring forward the well-known fact that, for no assignable reason, 

 menstruation frequently fails to appear at an expected date. The 

 hypothesis assumes that the bursting of the Graafian follicle takes 

 place ten to fourteen days before the commencement of menstrua- 

 tion, that corpus luteum being at the same time formed, the 

 secretory activity of which produces the menstrual period follow- 

 ing. Confirmation of this assumption was obtained in several 

 instances by Ancel and Villemin, who found that, in ovaries 

 removed from \vomen ten to twelve days before the date of the 

 next menstrual period, the Graafian vesicles were burst and quite 

 recent corpora lutea were present. This finding is less significant 

 than it appears, however, when we consider that the menstrual 

 swelling of the uterine mucous membrane takes place concurrently 

 with the ripening of the ovum in the Graafian follicle ; that it cer- 

 tainly begins before the bursting of the follicle (Ahlfeld),and that it 

 cannot, for this reason, be due to the agency of the corpus luteum. 

 In one operation Mandl actually observed an ovary containing a 

 mature, but intact, Graafian follicle, together with a uterus in 

 which the mucosa had undergone premenstrual changes. The 

 experiments of Hitschmann and Adler, to which reference has 

 already been made, next proved conclusively that the haemorrhage 

 is the least important .of the menstrual phenomena ; that it is, as 

 a matter of fact, merely an accompanying symptom of the cyclic 

 changes in the mucosa ; and that it is these which constitute the 

 essential feature of the menstrual process. It is hardly possible 

 that a stimulus of short duration, such as that provided by the 

 bursting of the Graafian vesicle, can be the fons et origo of the 

 entire cyclic process, nor can the haemorrhage itself be directly 

 due to that cause ; but the two processes, ovulation as well as 

 haemorrhage, must be regarded as the co-ordinated results of an 

 increased determination of blood to the genital organs. 



The prevailing views upon the relationship between menstru- 

 ation and ovulation are in need of considerable revision in the 

 light of Leopold and Ravano's investigations. The material at 

 the disposal of these authors was very large, and the conclusions 

 at which they arrived are as follows : 



Menstruation, that is, the periodic emission of blood by the 

 uterine mucous membranes, depends upon the presence of the 



