340 THE PHYSIOLOGY OF REPRODUCTION 



not occur simply as a consequence of the presence of the 

 ovum. It is also pointed out that in normal pregnancy the 

 uterine changes commence before the ovum enters the uterus. 



Again, the theory that the corpus luteum is responsible for 

 the attachment and early development of the embryo receives 

 some support from those cases in which pathological conditions 

 in the embryo have been found associated with pathological 

 conditions in the corpus luteum.-^ Thus lutein cysts are 

 frequently found in apparent correlation with chorionepi- 

 thehomata. 



Fr aenkel's general conclusion s regarding the functions of 

 the corpus luteum may be summarised as follows : TJie corpus 

 luteum is^MJ uctless gland w hichjs j-enewed every four^ weeks 

 during reproductive hfe in the human female, and at different 

 intervals in the various^ lower Maminals. Strictly speaking, 

 there is only one corpus luteum which represents the ovarian 

 organ of internal secretion, and is regenerated periodically in 

 shghtly different positions in the ovaries. Its fu nction is to 

 control thejmtrition of the uterus from puberty unt il the men o- 

 pause, to prevent it from lapsin g into the infantile condition or 

 undergoing atrophy, an d to prepare its mucous membrane 

 for the maintenance of the ovum. If the^oyum be fe rtilis ed, 

 the corpus luteum is responsible for maintaining the raised 

 nutrition of the uterus during the first part of gestation. If 

 the oviim be^unlertilised it merely produces the hypersemia of 

 N menstruation, and then undergoes degeneration until it is 

 renewed in a fresh position. Since the corpus luteum is, par 

 exceUeiice, the ovarian gland, " lutein " or the extract of this 

 organ, and not preparations of the entire ovary, should be 

 employed for the purposes of ovarian medication. 



Reasons have abeady been given for concluding that this 

 extended theory of the meaning and function of the corpus 

 luteum is untenable (p. 334). The fact that in a very large 

 number of animals, heat, and presumably, therefore, ovulation, 

 occur at infrequent intervals does not support it, while it has 

 been shown that, in some animals at any rate, ovulation does 



^ Of. Malcolm Campbell, " Pathological Condition of tlie Ovaries as a 

 Possible Factor in the Etiology of Uterine Fibroid:;," Scottish Med. and Surg. 

 Jour., vol. xvi., 1905, 



