Howard : Tannin cells of persimmons 



571 



stage will show that most of the tannin is being or has been col- 

 lected into the tannin cells. The contents of the cells are becoming 

 more highly refractive and from this fact the cells can be identified 

 with considerable ease, even without any tannin test. The middle 

 lamellae have softened sufficiently to allow the cells to be separated 

 without rupturing the walls. At about the middle of this stage a 

 large proportion of the tannin cells show vacuoles between the 

 tannin mass of the cell and portions of the cell-wall (figure 5). 



Figure 4. Section of Japanese persimmon, showing projections extending be- 

 tween adjacent cells. Tannin cells (masses) dark and somewhat shrunken away from 

 the cell-wall. X I 5°« 



If the material is mounted in the fruit juice these vacuoles remain 

 unchanged, but if water be added the tannin mass expands, fills 

 out the vacuoles, and, if allowed to continue absorbing, there re- 

 sults a rupturing of the cell-wall. This is then followed by part 

 of the cell-contents being forced out into the surrounding media. 

 In the early part of this stage the contents thus escaping mingle 

 readily with water, but later on the material forms a globular-shaped 

 portion on the sides of the cell. Such a condition is shown in 



