536 GENCHO FUJIMURA 



particular organ which is needed for the absorption of nutrition 

 for the embryo first makes its appearance in a perfect condition 

 only after the epithelium of villi retrogrades and becomes thin. 

 On this score I am led to believe that the epithelium of vilh is 

 simply an organ of internal secretion, and that the ground is 

 extremely weak for the argument, which treats it as an organ 

 to take nutrition for the embryo, as has been generally conjec- 

 tured in the past. 



3. The phenomena of internal secretion in the stroma cells of villi 



The smallest of the stroma cells of villi is simply a ball- 

 shaped cell which is comparatively rich in protoplasm, and 

 within the cell body there is a large quantity of plastosomes 

 (fig. 27), but presently a somewhat large quantity of lipoid gran- 

 ules or vacuoles having various sizes appears within the cell 

 body (figs. 28 and 29) ; and- subsequently, as the cell grows in 

 size the chief ingredients of the cell body will be plastosomes 

 and vacuoles, while the appearance of the lipoids is not very 

 distinct. The image such as is seen in figure 34 is very seldom 

 met with. On the contrary, however, the vacuoles may be 

 deemed the almost constant ingredients of each cell, and 

 especially as the cell developes and grows in size they increase 

 the more in size and quantity, and present a highly foamy 

 structure which is characteristic of this kind of cell. Now, 

 if we consider the correlations between the different con- 

 stituents mentioned above, it will be found first that in these 

 cells the plastosomes are stained comparatively easily, and are 

 therefore very distinctly detected in each cell; and as regards 

 its quantitative relations, it will be noted that there is not the 

 least tendency in the plastosomes to decrease in quantity, even 

 though the functions increase and the cells enlarge, as was seen 

 in the epithehum of villi described above. On the contrary, 

 the plastosomes crowd together in large numbers in the various 

 protoplasmic sections of cell bodies, and they present the ap- 

 pearance of a new growth and multiplication in the sections 

 concerned (figs. 30, 31, 32, 33, 36, and 38). The only excep- 

 tion is that when the quantity of lipoids contained in the cell 



