428 . TorrEY: CYTOLOGICAL CHANGES 
(f. 5). All the cells, at a given time, are by no means at the 
same stage in the elaboration of the enzyme. This is especially 
the case after the first day. We may say, nevertheless, that the 
first and second periods of secretion are separated by an interval 
of from 36 to 48 hours. By this time the plumule has broken 
through, and the radicle is an inch and a quarter in length. The 
scutellar cells show now a notable increase in the number and size 
of the starch grains that they contain. This is of course due to 
the fact that, by virtue of the solvent action of diastase, the starch 
of the endosperm is being transported and stored up in the scu- 
tellum, where it serves as food for the growing plant. The usual 
reduction in size follows the swollen condition, and is accompanied 
by a collecting of the granules at the tips of the cells, and finally 
by a discharge of the enzyme into the endosperm. 
. From now on until the complete depletion of the endosperm 
and the final degeneration of the scutellum there are no sudden 
changes in the size of the secreting cells. There seems, on the 
other hand, to be a gradual, but steady, increase in size with a 
continual production of diastase by each cell independently of the 
others. During the fourth day the nuclei of many cells became 
filled again with granules and on the fifth these may frequently 
be seen breaking through the nuclear membrane and collecting 
at the tips of the cells directly, without at first becoming scat 
tered through the cell (£ 6). At the end of 11 days there are 
signs of degeneration in some of the epithelial cells. These com 
sist of an abnormal swelling and vacuolization of the cytoplasm, 
most noticeable at the ends of the cells towards the scutellum- 
After the lapse of 22 days the cytoplasm is very scanty and 
ragged. The cells have also become very greatly elongated. 
They are now at least three and a half times their length at the 
beginning of germination. The cell walls are thick and stratified. 
The nuclei still stain very darkly and are probably producing @ 
ferment for the dissolution of what is left of the cell walls of the 
endosperm. The starch grains have completely disappeared from 
the endosperm and the scutellar cells are mere skeletons (7. 7) 
The time given, at which various changes in the diastase secret: 
ing cells occur, is merely approximate and varies greatly acco 
ing as the conditions are more or less favorable for growth. 
