456 B ruse hi. — Researches on the Vitality and 
hydrolytic test, and preformed sugars almost disappeared — a new and 
important fact to which I shall return in another paper. The synthetic 
action of the amylase of Maize is greater for the enzyme of the endosperm 
than for that of the embryo, in which it may be entirely lacking (Exp. II) ; 
it exists only in the early days of evacuation, and afterwards it is over- 
whelmed by a powerful hydrolytic action which steadily increases. One 
can therefore maintain that amylase exists in the endosperm as a pro- 
enzyme or zymogen which becomes active during germination, possibly 
owing to contact with the air or through the action of cellular acids. It is 
to be noted that Reychler (’89), and Lintner and Eckhardt (’90) had 
observed after treating the gluten of Gramineae with dilute acid that 
it acquires a weak diastatic power ; it is evident that this gluten held fast 
a small quantity of pro-amylase. 
So we can no longer hold the view that the increase of diastase in the 
isolated endosperm constitutes a proof of the vitality of its cells, and one 
must turn to various methods of cell physiology. 
At first, use was made of the plasmolys method, which gave very 
uncertain results, because the abundance of reserve material accumulated 
in the cells prevented accurate observation ; but a trace of plasmolysis 
seemed to occur in the cells of the horny portion of the endosperm. On 
the contrary, by using the method of ‘ vital staining ’ (staining of living 
tissues) with methyl violet or aniline blue, one obtained a deep coloration 
of the whole farinaceous part and of some of the cells of the horny layer 
which lay most distant from the aleurone layer, while most of the cells 
of the horny portion, especially near the aleurone cells, did not take the 
stain ; the gradual passage from the living cells occurring at the periphery 
of the endosperm to the dead cells in the middle was very instructive. 
Nuclear staining was attempted by different methods. Those lying 
near the aleurone layer stain easily with iodine green, methyl green, and 
eosin ; they are less deformed and smaller, while the deformation and 
resistance to the stain increased in the farinaceous portion. So we cannot 
say that the nuclei are totally dead, but it is proved as a matter of fact that 
they will absorb none of those stains which are rapidly taken up by young 
and living cells. The nucleus is frayed and vacuolated, and shows increas- 
ing decrepitude from the periphery to the middle of the endosperm. 
Barley. 
All the above experiments were carried out with Barley (. Hordeum 
distichum ), and show that in the Barley endosperm evacuation, if not com- 
plete, is much greater than in Maize. T phosphoric acid again facilitates 
the endosperm emptying, while chloroform has a much less deterrent action 
than upon the Maize endosperm. These facts all indicate that the vitality 
of the Barley endosperm must be less than that of Maize. 
