462 Bruschi . — Researches on the Vitality and 
the periphery of the endosperm, is also retained in one or several sub- 
aleuronic layers, whence it lessens by degrees till it totally disappears 
towards the middle of the endosperm, as well as in the part near the 
scutellum. 
This is clearly seen in the Maize, the endosperm of which shows well- 
marked, though strangely deformed, nuclei in the cortical, glutinous portion, 
while they are not to be brought in evidence in the farinaceous central 
portion which forms the bulk of the endosperm. 
In Barley and Wheat, if any trace of vitality is conserved in the 
amyliferous cells, it must be sought in the immediately sub-aleuronic 
layers, the larger part of the endosperm being quite dead. 
The rapid dismembering of the Rye endosperm at the very beginning 
shows that it is entirely dead. Its disintegration is due to the influence of 
a powerful cytase that precedes the amylase action, and dissolves the middle 
lamellas, while the cellulose layers of the walls are retained for a long time. 
The cells become isolated, but remain entire with intact starch in the endo- 
sperm cavity, so that one can no longer speak of an endosperm tissue. 
A similar fact is to be noted in Wheat and Barley, but less marked and 
at a more advanced period of evacuation ; but the phenomenon does not 
occur in Maize, though a cytase becomes active during the evacuation 
of this endosperm also. 
The discrepancies of preceding authors are very likely due to the fact 
that they used different species of corn. So that Puriewitsch, Griiss, and 
Linz, who worked chiefly with Maize, are not wrong in describing its endo- 
sperm as partly living, while Brown and his co-workers are right in asserting 
that the endosperm of Barley is a dead magazine of reserve food. 
Between the partly living endosperm of Maize and the totally dead 
endosperm of Rye, and also between the different parts of a grain of Maize 
or Wheat, one finds a gradual decrease in vitality. Nevertheless a rapid 
self-emptying of isolated grass endosperms can take place, for they contain 
pro-amylase, pro-cytase, &c., which still exist after the death of the cells, and 
yield large quantities of active enzymes after soaking in water at ordinary 
temperatures. 
The amount of energy needed for the hydrolysis of starch and hemi- 
cellulose is very small, and can originate from the oxidasic, i. e. extra vital, 
respiration of the sugars formed. Herein one sees a difference between 
carbohydrate and oil reserves ; in the latter only vital activity can supply 
the energy needed for the complicated formation of sugars, starch, &c., from 
the reserve fat. Indeed, I have shown in other papers (’07) that the endo- 
sperm of the Castor-oil plant ( Ricinus communis) retains its vitality during 
the whole process of germination or artificial evacuation. 
