

130 MISSOURI BOTANICAL GARDEN 







form in some cells. At this time (f. 14) the endosperm 

 cells in contact with the raphe and the integument contain 

 more tannin than the inner ones, and it would seem that the 

 integuments serve in some measure to distribute the tannin. 



m 



already been 



As maturity is approached, many of the cells of the outer 

 integument lose their tannin. These are chiefly the epi- 

 dermis and an irregular zone of underlying cells, in all of 

 which not the least trace of tannin is to be found (f. 31). 

 The cells of the inner integument are all tanniferous. What 

 becomes of the tannin in the cells which definitively do 

 not contain it is not easy to say. There is no evidence that 

 it is removed to adjoining cells; on the other hand, there is 

 none that it is transformed, beyond the circumstance that 

 there is a considerable sclerosis of the epidermal cells. It 

 has been noted that of cells of similar origin, apparently, 

 in the endocarp, some become sclerosed and do not contain 

 tannin (or occasionally, very little), while others remain than 

 walled, and are tanniferous. This lends some probability to 

 the view that the tannin is used in physiological changes 

 in the individual cell. If, however, the removal of tannin 

 from the epidermis and underlying cells is to be explained 

 by lateral movement into those cells which are finally tan- 

 niferous, this happens long before the period of ripening, 

 and is not the rapid segregation described by Howard (l. c.) 

 in the pericarp of the persimmon. 



After ripening, the cells of the integument and raphe, with 

 the exception noted, are heavily loaded with insoluble aplas- 

 tic tannin. To this the deep brown color of the seed is 

 due. 



sum 



setting aside the endosperm for the present, are, during the 

 period of growth, supplied with plastic tannin which is 



over to the developing endosperm. During the same 



ed 

 od 



, in the raphe, but at length throughout both raphe 

 teguments. During the latter part of the interval be- 



