THE GENERATIVE GLANDS 403 



That the secondary female sex characters, especially those 

 of the genital tract, are dependent upon the interstitial cells of 

 the ovary in the same way as the secondary male stigmata are 

 dependent upon those of the testis, is, at present, not proved. It 

 has been shown that uterine atrophy after castration may be 

 inhibited by the agency of the Graafian follicles alone, without 

 the co-operation of the corpus luteum or the stroma cells (Bucura). 

 But apart from this finding, Bouin, Ancel, and Villemin dis- 

 covered that exposure to the X-rays has an entirely different effect 

 upon the ovary to that which it produces on the testicle. The 

 X-rays also exercise an elective destructive action upon the ovary, 

 the specific tissue affected being the Graafian follicles. There is 

 a reduction in the volume of the ovary, and a diminution of the 

 follicles and corpus luteum ; the interstitial tissue, on the other 

 hand, not only remains intact, but it hypertrophies. The uterus 

 becomes atrophied in the same way as after castration. In the 

 case of the testicle, as we have already shown, the fact that the 

 interstitial tissue remains intact guarantees the integrity of the 

 genital tract and of the secondary characters. 



From the knowledge which we at present possess, it appears 

 probable that the interstitial ovarian gland exercises a local 

 influence upon the physiological processes in the female genital 

 apparatus itself, and especially upon menstruation. The older 

 theory of an intimate connection between ovulation and menstrua- 

 tion is no longer tenable (Leopold and Ravano) ; moreover, the 

 careful investigations of Hitschmann and Adler have shown that 

 menstruation essentially consists, not in a haemorrhage, but in a 

 cyclic metamorphosis of the uterine mucosa. Hence we are 

 forced to assume a continuous production of the hormone by 

 which these changes are effected, the source of which can 

 only lie either in the Graafian follicle itself or in the interstitial 

 tissue. But the Graafian follicles are already present in the 

 immature ovary, and for that reason they can hardly be credited 

 with the same significance in this connection as the interstitial 

 gland, which attains its full development at puberty, shows signs 

 of a cyclic increase of function corresponding \vith menstruation, 

 and which, at the climacteric, undergoes involution. 



The morphological and functional resemblance between the 

 premenstrual uterine mucosa and the decidua, suggests that the 

 menstrual alteration of the mucosa is in the nature of a prepara- 

 tion, that it prepares the ground for the nidation of the fertilized 

 ovum. It is interesting to note that, according to Keller's 

 investigations, rut in bitches corresponds with human menstrua- 

 tion in that it is accompanied by changes in the uterine mucosa 

 similar to those of the premenstrual period, though, in the case 

 of the animal, haemorrhage is absent or very slight. Thus, rut 

 is also a preparation of the uterine mucosa for the reception of the 

 fertilized ovum. 



