EMBRYO, SEED AND CARPEL IN THE DATE. 127 



at once on the addition of reagents. 18 A careful study of the 

 development and nutrition of the embryo-sac previous to pol- 

 lination will, I believe, show that they behave in some such 

 way as suspected by Servettaz in, e. g., Hippophae rham- 

 noides. Unfortunately my material has not been suitable 

 for this. 



I have been able, however, to follow the behavior of the 

 antipodal cells after pollination. It appears that disintegra- 

 tion proceeds from the basal cell, operating successively on 

 the adjacent and the innermost (f. 4, 4a). The disintegra- 

 tion is preceded by the reduction of the nucleolus, and the 

 enlargement of those of the adjoining cells. The order of 

 disintegration is the reverse of that followed in Hippophae 

 and other Eleagnacese (Servettaz, L c. p. 354). Whatever 

 the explanation of the difference, their position at the end 

 of the elongated cells which represent the end of the vascu- 

 lar supply to the embryo-sac, as in Hippophae, the presence 

 and evident nutritive importance of tannin, the peculiar 

 thickening of the contiguous cell walls, and their ultimate 

 behavior, all offer positive evidence of their physiological 



lm 



It would similarly appear that the tapetum 19 is also impor- 

 tant. At the early stage of development both tannin and 

 starch occur in the inner integument and tapetum. 

 This tissue does not break down — is not digested by the 

 embryo-sac. The character of the tapetal cells indicates 

 that its nutrients are transferred to the embryo-sac, following 

 the decomposition of the thin nucellus. 



Just before, or, at any rate, immediately following polli- 

 nation, the endosperm begins a rapid chalazal growth, pre- 

 vious to the division of the secondary nucleus. In doing 

 so, it digests the tissue at the base of the embryo-sac quite 

 irregularly, and forms several cul-de-sacs which extend back- 

 ward beyond the antipodal pit. This is, for some time, left 

 projecting into the utriculum of the embryo-sac (f. 5). 



18 This is not the secondary staining of the wall spoken of by Stras- 

 burger in his Practical Botany. 



i 



* Goldfluss, 1899. 





