SECRETORY FUNCTIONS IN HUMAN PLACENTA 559 



there occurs a material formation which may be deemed a 

 secreted matter which is excreted by the cell body. 



The large-type decidual cells are remarkable in their ap- 

 pearance by the end of the first month of pregnancy, though 

 in the second month they appear to reach their climax, and in 

 the following third or fourth months, they diminish in their 

 size. And, the afore-mentioned secreting phenomenon which 

 is peculiar to these cells, begins in the second month, appears 

 most remarkably in the third month, and may be demonstrated 

 up to about the sixth month, though in the seventh month and 

 after it is no longer possible to observe it. In general, the 

 large-type cells retrograde and decay remarkably in the second 

 half of pregnancy, though at the end of pregnancy it is still 

 able to find them, and, moreover, at this period there are some 

 few cells which do contain a small quantity of lipoids. 



The functions of the glandular epithelium are most active 

 at the end of the first month of pregnancy, begin to drop 

 considerably from the beginning of the third month, in the 

 fourth month the decline is greater, and in the fifth month, it 

 appears, they almost come to a standstill. In general, the 

 functions make their appearance somewhat earlier in the decidua 

 serotina than in the decidua vera, and accordingly they stop 

 earlier in the former than in the latter. The secretions are 

 thrown out into the uterine cavity probably only in the earliest 

 period of pregnancy, and later as the openings of the glandular 

 tubules are closed by the placental formation and by the adhesion 

 of the decidua vera and decidua reflexa, the secretions, along 

 with the detrital matters of the degenerated glandular cells are, 

 of necessity, absorbed by the mother. 



5. Since it is possible that the secretions of the various kinds 

 of cell groups mentioned above are, for the most part, absorbed, 

 either by the mother or by the fetus, as in the case of internal 

 secretions, everybody will easily assent to the supposition that, 

 like the secretions of many internal secretory glands, each of 

 them contains a certain hormone, and should this be the case, 

 it may be said that each of the two organs concerned is assur- 

 edly a producer of hormones of various sorts and kinds, and is 



