148 



MISSOURI BOTANICAL GARDEN 



d. A zone from which the protoplasm is disappearing, and in con- 

 sequence, the oil becomes agglomerated. The reserve cellu- 

 lose begins to undergo change. This zone takes up Bismarck 

 Brown more readily than elsewhere. (Outer part of Sachs' 



e. 



middle zone.) 

 Unchanged endosperm. (Sachs' corresponding layer.) 



has 



show that the agglomeration 



coincident with the disappearance 



m 



and 



that the disappearance of oil begins when the cell-walls are 



membranes. This harmonizes with' 



du 



ited endosperm remains the same (7-9% 



m 



matiere 



de 1 albumen n'est absorbee par le cotyieaoi 

 mesure de la digestion des parois memes 



des cellules de 



l'albumen" (1899, p. 396). 



may be observed 



that the relative amount of oil in zone c is greater than else- 

 where, because of the reduction in the amount of both the 

 protein and reserve cellulose. The comparison of the be- 

 havior of oil and protein during embryogeny and during 

 germination shows further that the facts are identical, while 

 the cessation of growth in the endosperm and the presence 

 of reserve cellulose remove one condition, the presence of the 

 tension zone, and impose another, the necessity of digesting 

 the reserve cellulose, a different material from any attacked 

 by the embryo pr 



seems obvious, that during the embry 



em 



bryo, changed into water-soluble substances. This conclusion 

 must be extended to the period of germination. Sachs be- 

 lieved to the contrary, for the reason, before stated, that oil 



d 



mm 



and because the immediately underlying layer of epithelium 

 also contains oil-droplets 30 (1862, p. 250). The presence of 



30 



cytology 



the date appears to have overlooked the important modifications in 

 the appearance of the cytoplasm, and possibly of the nucleus, which 



