825 
Embryo and Aleurone Layer of Hordeum. 
is a much attenuated network of cytoplasm, the meshes of which are 
densely crowded, principally with variously sized starch grains, and among 
the other far less abundant inclusions are those of a protein nature. 
Immediately external to the amyliferous cells is the aleurone layer, 
forming as already stated, with the exception of that portion of the inner 
endosperm which abuts on the scutellum, an investing envelope to the entire 
inner endosperm. External to the aleurone layer is the spermoderm com¬ 
prising the different external integuments of the seed. 
The principal point of interest in the present inquiry refers to the 
question as to whether or not the inner endosperm, independently of the 
amyloclastic secretions of the embryo and aleurone layer, possesses a capacity 
for self-depletion, and if so, in what degree transformation of the starch 
storage reserves is induced solely by the pre-existent amylase of the 
resting seed. 
The conclusions of the different investigators who have attacked this 
aspect of the question are marked by their extreme divergency. 
Brown and Morris (loc. cit. p. 482) state that the inner endosperm 
consists of a mass of non-living cellular units which are unable to induce 
self-digestion of their starch contents. 
Hansteen (loc. cit.) and also Puriewitsch (loc. cit.) contend that the 
endosperm of barley is self-digesting and that each cell of the inner endosperm 
is a living functionary unit. 
The claim of vitality for the inner endosperm rests almost entirely on 
the demonstration of enzyme action in this tissue, this constituting a criterion 
which, as already stated, is no longer regarded as valid in determining 
whether a tissue possesses vitality or otherwise. Although Puriewitsch’s 
view is opposed to Haberlandt’s conclusion that the aleurone layer possesses 
a secretory function, yet many of his experimental results really suggest and 
support the correctness of Haberlandt’s contention. 
Brown and Escombe, 1 as a result of a reinvestigation of the work 
of Brown and Morris (loc. cit.), modify the views of the latter authors 
materially. 
The statement by Brown and Morris that the accumulation of amylase 
which occurs in the inner endosperm during the germinative process is 
largely due to the secretory activity of the embryo they amend by con¬ 
ceding that the contributory share in the sum total of the amylase found 
in the endosperm furnished by the embryo was, no doubt, considerably 
over-estimated. On the other hand, they substantiate Haberlandt’s 
suggestion that the aleurone layer possesses glandular functions and claim 
that it plays a much greater role in endospermic depletion than had hitherto 
been assigned to it. 
Experiments devised to ascertain if the isolated inner endosperm 
1 Proc. Roy. Soc., Ixiii, 1898, p. 3. 
