SECRETORY FUNCTIONS IN HUMAN PLACENTA 561 



part of pregnancy. And, even in this case secretions of several 

 kinds, even if they come from cells of one and the same origin, 

 would possibly be, by no means, similar in quality, but rather 

 in the organ concerned, there would be existent various kinds 

 of substances produced from the various cell groups which form 

 the organ. And, in case that there is a certain hormone action 

 in these substances, it would follow that, during a certain period 

 of pregnancy, the hormones will act upon both the mother and 

 the fetus in diverse and complex manners. 



9. The histological changes which the interstitial cells of the 

 uterine mucous membrane and glandular cells undergo prior 

 to menses resemble, in general, the changes which take place at 

 the beginning of pregnancy, though they are by far the weaker. 

 Therefore, even in that case, these two kinds of cells, looked 

 at from their histological structure, have in common to them- 

 selves, secreting functions, to whose existence we may positively 

 assert. And, the secretions, if in the interstitial cells, are un- 

 doubtedly absorbed internally, as in the case of the small-type 

 decidual cells while in pregnancy, and should thereby bring 

 about the various clinical symptoms which are experienced dur- 

 ing menses. 



The glandular cells differ from the former, and the secre- 

 tions have probably no endocrine nature and are immediately 

 thrown out to the outside, viz., into the uterine cavity, so 

 that it would be difficult to attach to them an important 

 physiological signficance, such as hormone action. Rather, it 

 would be fit to interpret such periodical changes of these cells 

 as preliminary phenomenon of the coming pregnancy. 



10. The interstitial cells of the uterus, prior to menses, are 

 developed into the so-called menstrual decidual cells, which in 

 point of structure, distinctly reminds us of the decidual cells 

 of pregnancy. For this reason, it would be in order for us to 

 trace the origin of the latter, as of the former, to the interstitial 

 cells of the uterus. 



