574 



Howard : Tannin cells of persimmons 



When the last stage of the chang 



ry 



The addition of water 



causes 



sure upon the cover slip resulting in the fracturing of the tannin 

 mass into irregular fragments (figure 7). These fragments tested 

 for tannin give strong reactions showing that no fundamental change 

 has taken place in the distinctive character of the tannin radical. 

 This stage of ripening is evident to the taste, for all astringency 





4 





■s. 



m 







* 



* ' 



.frr- 



■*• 











Figure 7. Tannin cells in ripe condition, after pressure has been applied, break- 

 ing the mass into fragments. X 2 5- 



has now disappeared. Right here it may not be out of place to 

 call attention to the fact that finally the tannin masses may be 

 either of watery clearness in color or else of dark amber-brown 

 color. There is, however, a difference in surface outline of the 

 two kinds, in that the clear form has a fairly even surface with 

 more or less of slight wrinkling while in the brown type hemi- 

 spherical hollows in the surface seem to be always present in 

 greater or less extent (figure 8). Hollows are very rarely ob- 

 served in -the clear type. The brown type has not been observed 



