THE REPRODUCTIVE ORGANS 75 



criticism of the theory of prostatic internal secretions is that 

 it is unlikely on phylogenetic grounds, that the functional 

 activity of the essential organ of reproduction should depend 

 on the presence of an accessory gland of comparatively recent 

 evolutionary development. Further, Dr. Halpenny, working 

 in my laboratory, has repeated the experiment upon dogs. 

 In these there was certainly no appreciable effect upon the 

 testes. 



There are several reports of cases of prostatic enlargement 

 in which good results are said to have followed the administra- 

 tion of extract of prostate. Such extracts are also affirmed to 

 be of value in increasing the contractions of the bladder. 



C. The Internal Secretion of the Ovary and the Corpus 



Luteum 



The ovary in mammalia consists of a connective tissue 

 stroma, with bloodvessels, lymphatics, and nerves, enclosing 

 the Graafian follicles with the ova. At certain periods there 

 are corpora lutea and atretic follicles, and in certain species 

 the "interstitial gland." 



Cyclical changes occur both in the ovary and in the uterus. 

 In the ovary these consist of ripening of the follicle, ovulation, 

 and formation of the corpus lute'jm. In the uterus we have to 

 deal with the structural changes which accompany the cestrous 

 cycle, consisting of growth of the mucous membrane with 

 increased glandular activity, followed by regression and period 

 of rest. 



The quiescent period is called the " ancestrum." The 

 " pro-oestrum " is distinguished by increased vascularization 

 of the reproductive organs, which reaches a climax at the 

 period of "oestrus" or "heat," during which only in the 

 majority of animals the female will admit the male. In the 

 human subject and the primates generally menstruation 

 corresponds to pro-oestrum in the lower animals. 



If conception occurs, oestrus is followed by gestation, lacta- 

 tion, and finally succeeded by another ancestrum. But if 

 conception does not take place, oestrus is followed by metoes- 

 trum, during which there is a return to the normal on the part 

 of the whole system. 



The following scheme is given by Hill and O'Donoghue 



