IMPREGNATION '437 



mucus does not clot. The ammoniacal odor is due largely to needless 

 decomposition in the vagina. The normal biological odor sometimes 

 to be distinguished about menstruating women is a very different odor; 

 it comes from the skin, and is somewhat aromatic and by no means 

 unpleasant (Ellis). The mucosa partly given off during the periods is 

 regenerated in a week or less after the flow ceases. 



THE RELATION OF OVULATION TO MENSTRUATION is still somewhat 

 uncertain; the most likely theory has already been discussed. That 

 there is a relation and a dependence may not be doubted, as we have 

 seen. Yet girls sometimes conceive and bear children before they have 

 menstruated, and so occasionally do women years after their menses 

 have ceased at the climacteric (menopause). It is certain, then, that 

 menstruation is not essential to normal conception, while ovulation 

 obviously is, for without the freeing of the ovum the sperms could not 

 gain access to the latter. The chief problem then is as to the function 

 of the monthly flow. Another question not less important, practically 

 as well as theoretically, is the time-relation of menstruation to ovula- 

 tion, since everywhere the menses are used as a sort of almanac for 

 predicting the date of delivery. These problems are made yet more 

 difficult by our ignorance of just what happens in the ovaries during the 

 reflex excitement of coitus. On FraenkePs hypothesis, ovulation should 

 occur rhythmically once a month two weeks before menstruation, the 

 rhythm depending on entirely unknown conditions perhaps in the ovarian 

 tissues. From this point of view coitus would have little influence in 

 rupturing Graafian follicles, and the musculature of the ovaries fails of a 

 known function. If we suppose, then, that menstruation is occasioned 

 by the degeneration of the uterine mucosa after being disappointed 

 in its expectation of feeding a fertilized ovum, we shall be as near to an 

 explanation of the menses as can be had at present. 



The evidence that some internal secretion of some part of the ovary 

 occasions the monthly flow is very conclusive, for removal of all of both 

 ovaries stops menstruation permanently, while if only a small part of 

 one ovary be left the process continues. This is quite in line with the 

 conditions under which enzymes in general work. Moreover, after 

 complete removal, with cessation of the catamenia, the successful trans- 

 plantation (Glass) into the abdominal cavity of a fragment of ovary 

 again starts the menstrual rhythm. In the over-radical gynecology of 

 a decade ago there were all too many opportunities for testing these now 

 well-known facts. Experiments on the transplantation of corpora lutea 

 only remain to be performed. 



IMPREGNATION. 



Biologically considered woman is female in order to bear children and 

 to nurture them during their uniquely long childhood. The first step 

 in this long and complex process in which the girl becomes a woman is a 



