THE GENERATIVE GLANDS 381 



appearance of the interfascicular connective tissue. The exhibition 

 of ovarin 'merely reduces, to a certain extent, the obesity which 

 follows castration. 



The influence which the ovary has upon the uterus is further 

 shown by the fact that, after cessation of ovarian activity, 

 menstruation ceases in women, and the analogous rutting sym- 

 ptoms in animals disappear. 



That menstruation is dependent upon the ovary was first 

 suggested by Sintema in the i8th century, though upon no 

 positive grounds. It was Bischoff (1844) who first suggested, 

 upon histological grounds, that ovulation, that is the periodical 

 maturity and release of the ovum, was coincident with menstrua- 

 tion, and that the latter was an expression of ovulation. Pfliiger 

 (1865) explained this relationship as follows : Stimuli accumulate 

 in the maturing Graafian vesicle which, acting reflexly through 

 the nerves, bring about a superfluity of blood in the genital 

 organs ; this causes the bursting of the follicle and release of the 

 ovum on the one hand, and on the other, the discharge of blood 

 from the uterus. 



Strassmann succeeded in producing symptoms resembling rut 

 by increasing the blood-pressure in the ovaries of bitches, and 

 these results seemed to confirm Pfliiger's theory. 



But isolated findings in both man and animals suggested the 

 possibility that the relationship between the ovary and the 

 phenomena of menstruation and of rut, was effected by a chemical 

 agent. Halban's experiments with apes proved that this assump- 

 tion was well founded. Female baboons (Cynocephalus) have a 

 menstruation similar to that of the human female. When the 

 ovaries of these animals were extirpated and implanted under the 

 cuticle of the abdomen, menstruation occurred in the same way 

 as under normal conditions ; it ceased, however, as soon as the 

 implanted ovaries were removed. According to Marshall and 

 Jolly, the implantation in castrated bitches of ovaries in a state 

 either of, or preceding, rut, or the injection of the extract of such 

 ovaries, is followed by swelling of the vulva and other phenomena 

 of the rutting state. 



It has frequently been found possible to maintain the process 

 of menstruation in women by the re-implantation or transplanta- 

 tion of the ovaries (Cramer, Pankow). 



van der Velde's statement that menstrual haemorrhage may 

 be procured at the physiological climacteric by means of ovarian 

 tabloids, must be accepted with a certain amount of reservation. 



It is evident then, from what has gone before, that the hor- 

 mone which is formed in the genital glands and by them passed 

 on into the blood-stream, supplies stimuli which are necessary to 

 the normal development and subsequent anatomical integrity of 

 the genital organs, as well as to their physiological activity. 



It is certain, however, that the influence of the genital glands 



