THE FEMALE REPRODUCTIVE ORGANS. 879 



its physiological value lies in the fact that a raw surface is thus made 

 upon which the ovum is grafted. Menstruation, according to him, 

 is an operation of nature for the grafting of the fertilized ovum 

 upon the maternal organism. This view finds considerable support 

 in the fact that in some of the lower animals (dogs) the flow of 

 blood (prooestrum) precedes fertilization. 



The Effect of the Menstrual Cycle on Other Functions. It 

 is natural to suppose that such marked changes as occur in the 

 ovary and uterus during the menstrual cycle should have an in- 

 fluence upon other parts of the body. As a matter of fact, it is 

 known that in general the sense of well-being varies with the phases 

 of the cycle. At the time of or in the period just preceding the 

 menstrual flow there is usually a more or less marked sense of ill- 

 being or despondency, and a diminution in general efficiency. 

 Among the various observations made by objective methods upon 

 the functions of the different organs during these periods the most 

 significant, probably, are those upon blood-pressure. According 

 to Mosher,* the blood-pressure falls at the time of the menstrual 

 periods. The curves obtained in these experiments are not entirely 

 regular, but at or near the menstruation the blood-pressure falls 

 slowly, the maximum fall being coincident with the appearance of 

 the flow. It would seem probable that the fall of general blood- 

 pressure is due directly to the vascular dilatation in the genital or- 

 gans and in turn is responsible for some of the secondary phenomena 

 observed in the organism as a whole. It is very suggestive to find 

 that the author quoted above obtained similar periodical falls in 

 blood-pressure in men, suggesting the idea that has frequently been 

 expressed, that in man as well as woman there is a rhythmical 

 activity of the genital organs, a reproductive cycle that in man 

 may be referred to the development and extrusion of the sperma- 

 tozoa in the testis, as in woman it is connected with the growth and 

 expulsion of the ova in the follicles of the ovary. 



The Passage of the Ovum into the Uterus. The means by 

 which the ovum gains entrance to the Fallopian tubes has given 

 rise to much speculation and some interesting experiments. It 

 was formerly believed (Haller) that at the time of ovulation the 

 fimbriated end of the Fallopian tube is brought against the ovary, 

 the movement being due to a congestion or a sort of erection of the 

 fimbrise. This movement has not been observed, and, as experi- 

 ments show that small objects introduced into the pelvic cavity are 

 taken up by the tubes, it is believed that the cilia upon the fimbriae 

 and in the tubes may suffice to set up a current that is sufficient 

 to direct the movements of the ovum. Attention has been called 

 to the fact that in animals with a bicornate uterus the ova may 

 be liberated from the ovary on one side, as shown by the presence 

 * Mosher, "The Johns Hopkins Hospital Bulletin," 1901. 



