SECRETORY FUNCTIONS IN HUMAN PLACENTA 539 



increase in quantity (figs. 44, 48, 50, 51, and 52). The lipoid 

 granules arise at the beginning in a very small granular body, 

 whence they grow up to a certain degree, when clear halos ap- 

 pear around them, and the manner in which they directly 

 participate in the formation of vacuoles (figs. 44, 46, 52, and 53) 

 is the same as what is observed in the epithelium and the stroma 

 cells of villi. And sometimes it occurs that the vacuolar for- 

 mation appears equally at a time within one and the same cell 

 body, and as a result the foamy image of high degree, such as 

 is illustrated by figure 49, is brought into being, but this is rather 

 rare, and in most cases the vacuoles vary in their sizes. And, 

 besides, it is customary for the vacuolar formation in most 

 cases to contain at the same time groups of plastosomes or 

 Upoids of different sizes. In short, the smaller-type decid- 

 ual cells entirely agree with the stroma cells of villi in their 

 structure, and, therefore, there is no need for argument that 

 their secreting phenomena should be dealt with in the same 

 manner as the latter. On this score, I will not go to the redund- 

 ant trouble of touching upon the secreting process of the smaller 

 type decidual cells here, but will confine myself to the brief 

 statement that the function is repeatedly performed by the 

 same methods as in the stroma cells of villi. 



If we take a glance at the figures in the plate, it will be quite 

 clear that the smaller-typed decidual cells, repeatedly perform- 

 ing as they do the functions as described above, develop and 

 increase in size more and more, and passing through the 

 various intermediate types (figs. 52 to 54, 62 and 63) grad- 

 ually, as I mentioned in the previous chapter, pass into the 

 larger-type decidual cells to attain the height of their growth. 

 Therefore, the demarcation between the large and small types 

 in the decidual cells is, after all, due to the difference in the de- 

 gree of growth of the same kind of cells, and the smallness of the 

 cell should be taken for an indication of comparative infancy, 

 while the largeness of the cell shows that it has attained the 

 region of perfection in its growth. 



The large-type decidual cells may be divided into two kinds 

 with respect to structure. One represents the kind of cells whose 



