INTERNAL SECRETION OF OVARY 263 



(c) Objections to the theory of the internal secretion of the 

 corpus luteum. 



Objections have been made to the assumption that the 

 corpus luteum causes menstrual changes or the characteristic 

 cycUcal changes of heat. These objections have been discussed 

 especially by Aschner (1918, pp. 46-57) for menstruation, by 

 Marshall (1910, pp. 336-345), and by Marshall and Runciman 

 (1914) for the oestrous cycle. 



It has been pointed out by different authors that the time 

 relations between the formation of the corpus luteum and the 

 appearance of the menstrual changes in the uterine mucosa 

 cannot be taken as a proof that a connection exists between 

 the two. It has been claimed that the uterine changes begin 

 before the folhcle is ruptured, i.e., at a time when the ripe 

 Graafian foUicle is stih present. More recently Schickele (1921) 

 has insisted on the fact that the premenstrual uterine changes 

 may occur when no corpus luteum is to be detected in the 

 ovary, and that there may be a corpus luteum in the ovary 

 without premenstrual changes taking place in the uterus. A 

 similar standpoint is taken by Henry (1922). It has been also 

 found that after removal of an ovary with a corpus luteum 

 menstruation occurred two or four days after the operation. 

 The authors concluded from the latter observation that the 

 corpus luteum inhibits menstruation. A further proof of this 

 assumption, according to Aschner, exists in the fact that 

 several days after removal of one or both ovaries a bleeding 

 from the uterus may often occur, and that women with a uni- 

 lateral cyst of the corpus luteum show amenorrhoea. We shall 

 show below that these chnical observations are by no means 

 contrary to the conception of the endocrine function of the 

 corpus luteum. 



Menstruation occurs also in monkeys without ripe folHcles 

 or fresh corpora lutea being present at the time of menstruation 

 (Heape). The same is true for "heat" in the lower mammals. 

 In various species of bats heat and copulation occur in the 

 autumn, whereas ovulation takes place only in the following 

 spring; the spermatozoa are kept during the whole hibernation 

 in the uterus It seems clear that in this case the heat cannot be 

 caused by a corpus luteum or by a ripe Graafian folUcle. In 



