Self -digestion of the Endosperm of some Graminaceae . 459 
no choice but to admit that cytase production occurs only in the aleurone 
cells, or at most in the directly sub-aleuronic layers. 
Wheat was used for a comparative study, by staining methods, of what 
happens in the amyliferous cells of the seed from the time of the beginning 
of endosperm formation up to the ripening of the seed. 
Results were chiefly obtained by staining properly-fixed material with 
iodine green, methyl green, malachite green, gentian violet, and by double 
staining with methyl or malachite green and eosin, gentian violet and eosin, 
iodine green and orange. With single staining, both in the first stages of 
endosperm development and in more advanced stages (but always green), 
a sharp coloration of the nuclei in the starchy cells was obtained. These 
nuclei were easily distinguished among the starch grains, though the latter 
were present in great abundance in the later stages and had reached their 
proper size. 
Eosin and orange gave a coloration of the cell protoplasm, while the 
nuclei absorbed their peculiar stains as iodine green, methyl green, mala- 
chite green, gentian violet, &c., in other stainings, and were clearly distin- 
guishable in the middle of the cells, showing a perfectly normal structure. 
As it might be thought that in sections of old endosperms which 
had been boiled in dilute acid in order to remove the starch, the nucleus 
would have lost its property of absorbing its peculiar stains on account of the 
treatment received, young cells with normal nuclei were treated in the same 
way. In spite of the treatment the nucleus and protoplasm of all the 
endosperm cells still retained to the full their property of absorbing stains. 
So it cannot be said that the removal of the reserve starch by dissolving 
out with dilute acid alters the chemical composition of the nuclear sub- 
stance, even in ripe and germinating endosperms, sufficiently to hinder 
staining. 
From all these observations it can be inferred that the cells of Wheat 
endosperms do not regain vitality during germination ; but the fact remains 
that they can empty themselves, even when cut off from the embryo, by 
means of the activation and functioning of their amylolytic enzymes, and 
that chloroform has a remarkable inhibiting action on this evacuation. 
Rye. 
With Rye {Sec ale cereale ) a total evacuation of the endosperm was 
obtained by the same methods, with a copious diffusion of reducing sugars 
and other digestion products (albumins) in the surrounding liquid ; in the 
early stages of germination there occurred a complete disintegration of the 
starchy tissue by separation of the individual cells. Chloroform has no 
action upon the starch hydrolysis, nor on the dissolution of the walls, nor on 
the evacuation of the entire endosperm, for, though the seeds became a little 
