EMBRYO, SEED AND CARPEL IN" THE DATE. 119 









les parties de Fovule . . ." (p. 353). Servettaz, fur- 

 ther, inclines to the belief that the tannin may be employed 

 in the nutrition of the embryo-sac, and advances the interest- 

 ing view that antipodal cells play an active role in the 

 process: ". . . les tannins amenes a la base du nucelle 

 <eraient transformers en glucose par la 'cellule antipode' qui 

 occupe l'extremite du sac embryonnaire, car cet organe ne 

 renferme pas de tannins . . ." (p. 411). He concludes 

 that, though tannins occur in such situations that they must 

 be considered a waste, he also takes the position that they are 

 in other situations useful, and cites the finding of Gerber 

 (1897), w T ho has shown that tannins give rise to glucose dur- 

 ing the maturation of some fruits. 



In what follows it is hoped to show that (1) in the date 

 tannin occurs in special cells in such a state that we are 

 precluded from supposing that it serves any but secondary 

 functions, such as protection, as shown by Vinson (1909). 

 This tannin is aplastic. (2) That there is no condensation 

 of tannin just prior to ripening, meaning by this a move- 

 ment of tannin from the surrounding parenchyma to the 

 special cells or idioplasts. (3) that tannin (plastic) occurs 

 and disappears at such times and in such situations as to 

 warrant the conclusion that it is a nutrient, and in this is 

 analogous to starch, reserve cellulose, oil, etc. 



Carpel. Hypodermal tanniferous zone (f. 33). The 

 parenchyma cells lying between the epidermis and the zone 

 of stone cells are more or less flattened radially, and take 

 up, with the epidermis, a thickness of about 60 microns, of 

 w r hich the epidermis accounts for 15. In the Rhars, the 

 majority of these cells, usually excluding the epidermis, con- 

 tain tannin, and thev constitute a zone one to three cells 

 in thickness, immediately beneath the epidermis. Occasional 

 cells among them are sclerosed and may also contain tannin. 

 In Deglet Noor there is a similar zone, but usually of only 

 one cell in thickness. The hypodermis of commercial dates 

 displays the same tanniferous layer, the cells containing tan- 

 nin "vacuoles/' or masses lying in the vacuoles. In material 

 fixed with a chromic acid mixture, the tannin does not ap- 



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