570 



Howard : Tannin cells of persimmons 



localized, for though it appears most abundantly in the loose 

 parenchyma-tissue where the tannin cells are located, yet it is not 

 limited to these cells nor even to the region where the cells are 

 most abundant. Microchemical tests show that tannin is abundant 

 in most of the cell- sap of the parenchyma-cells and even in the 

 intercellular portions. In this stage it is somewhat difficult to 

 identify the cells which are afterwards to figure as tannin cells 

 except by means of the size and shape, which as noted above 

 strongly differentiate them in some varieties. At this stage the 



k 



i 



Figure 3. Tannin cells from Japanese persimmons (Kaki). X 25. 



cell-contents appear to be in as perfectly liquid condition as any 

 other cells around them. 



The second stage of ripening, the transitory, is the one in which 

 the most radical changes occur in the physical and possibly in the 

 chemical constitution of the tannin. This stage in the native 

 American variety is signalized by a slight decrease in the firmness 

 of the fruit, and not long afterward by a marked tendency toward 

 softening. Examination of the tissues in the early part of this 



