548 GENCHO FUJIMURA 



There is, of course, a certain limit to the growth of each cell, 

 but there is something exceptional about the decidual cell. It 

 rises from certain extraordinarily small spherical cells within 

 the proper mucous membrane of uterus, and yet it grows so 

 very rapidly and becomes enormous in size that the classi- 

 fication between the large and small types in the ordinary de- 

 cidual cells, if dealt with according to their genesis, should be any- 

 thing but significant. For these two mutually run over to 

 one another through the intervention of the intermediate 

 type, and no sharp demarcation exists between them. There- 

 fore, these two kinds, histogenetically, belong to exactly the 

 same kind of cell, and they only differ in that one is still young 

 in its growth while the other has already perfected its growth. 

 However, it must be noted here particularly that the two pre- 

 sent an entirely different appearance histologically, and, there- 

 fore, in all probability, along lines of their physiological 

 functions. In other words, the decidual cell entirely changes its 

 structure and functions along with the perfection of its growth. 

 That is to say, the decidual cell which has perfected its growth 

 no more demonstrates within its body any important tissue in- 

 gredients, except plastosomes; however, it seems that probably, 

 at this period, the cell prepares, by means of the special action 

 of a very strongly developed cell membrane, certain secretions, 

 and sends them forth into the interstitium. At any rate, the cell 

 passing through this stage gradually withers and becomes smaller. 



The secretions, while at the height of their formation, are 

 congiutinated with one another, produce in abundance vacu- 

 oles of various sizes and shapes, and will show a high beehive 

 structure. And the way of their removal and absorption, if 

 in the syncytium layer, will be, undoubtedly, by rupture, sooner 

 or later, toward the intervillous spaces, and thus they will be 

 absorbed in the mother's blood, while in the various other cells, 

 there is no knowing but that the secretions are thrown out by 

 osmosis, and the secretions of the Langhans' cells and the stroma 

 cells of villi should, as a matter of course, be absorbed on the side 

 of embryo, with the exception of those, which, finding their out- 

 lets in the Langhans' islets, are probably taken in by the mother's 



