S toward. — On Endospermic Respiration in Certain Seeds. 417 
provision for the escape of the mobilized products of change derived from 
the supposed inactive storage-tissues of the latter. 
He asserts that in the case of oily seeds, on account of the peculiar 
nature of the metabolism associated with them — oil first undergoing trans- 
formation into starch — the inhibitory influence of the accumulated products 
of self-digestion would not manifest itself so early as in the case of starchy 
endosperms. Hence, while auto-depletion might be observed in the case 
of the endosperm of Ricinus , it might not be in the Gramineae because of 
its early inhibition in their case. 
He further claims to have himself demonstrated the self-depletion of 
the non-growing and apparently inactive endosperms of Hordeum and Zea, 
when placed under sterile conditions of germination, and when, also, ample 
opportunity was given for the removal of the products of mobilization and 
depletion. 
Linz (7), in a study of the physiology of germination of maize, claims 
from the results obtained with the isolated endosperms of this seed, which 
were placed under germination conditions for twelve days and showed 
a marked increase in sugar content, that they possess vitality. 
Puriewitsch (8), utilizing in the main the method of experiment devised 
by Hansteen, and conducting his experiments in such a manner that the 
absence of micro-organisms was assured, observed the corrosion of starch 
grains and the more or less advanced depletion of the endosperms of barley 
and maize. 
He considers that the endosperms of the Gramineae should be regarded 
as living organs, and that each individual cell of the endosperm is capable 
of functioning autonomously as a living unit. 
Brown and Escombe (9) subjected the work of Brown and Morris to 
a re-investigation which resulted in a demonstration of both a cytohydro- 
lytic and an amylohydrolytic capacity in the aleurone cells of barley. 
They were, however, unable to demonstrate an amylohydrolytic 
capacity for the amyliferous cells. Fragments of endosperm deprived of 
their aleurone layer, which were placed under conditions favourable for 
germination, and the ready outward diffusion of any soluble metabolic 
products, showed no difference as compared with similarly prepared ones, 
previously treated with saturated aqueous chloroform for a sufficient length 
of time to extinguish any residual vitality they may have possessed. 
The general conclusion to be derived from these later experiments of 
Brown and Escombe on the barley endosperms appears to be that the 
aleurone cells are endowed with a depletive capacity, and are probably 
living, while the amyliferous cells possess no such capacity and probably 
do not possess vitality. 
Quite apart from any possibility of determining whether the amylifer- 
ous cells of the endosperm-tissue of barley and maize do or do not 
