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O' Brien . — The Proteids of Wheat. 
by Brown and Morris 13 , but their experiments do not seem 
exclusive of the possibility of some such function of the 
aleuron-layer, accessory to the scutellar epithelium. For, 
as already shown, there is no necessity for a stimulus from 
the embryo (if such be needed) to traverse the lifeless endo- 
sperm to reach the aleuron-layer, since the two are in contact 
below the furrow, towards the base of the grain. Nor does 
a decreased diastatic activity of the aleuron-layer after the 
embryo is detached necessarily prove that the enzyme comes 
from the embryo. Again, though in Barley the course of 
starch-dissolution may be independent of the aleuron-layer, 
this does not seem to be the case in Wheat. For while 
towards the tip of a germinating grain (four days) the starch- 
grains in the centre of the endosperm are intact, those in the 
cells immediately underlying the aleuron-layer have already 
begun to undergo dissolution, showing the characteristic 
radial pittings — and this both on the dorsal and the central 
face of the seed. But I have given no special attention to 
the question of the function of the aleuron-layer. 
However, it rests with those who consider the aleuron-layer 
merely as a specialised reserve store to explain why it consists 
of apparently living cells with a large and perfect nucleus, 
whilst the rest of the endosperm-cells, as shown by Brown 
and Morris, are lifeless. In any case, it seems to me that 
cultivated grain, with a much larger proportion of starchy 
endosperm than that naturally present in the Gramineae, is 
hardly the best material from which to form an opinion as to 
the normal functions of the aleuron-layer. 
The Aleur on- Layer of other Cereals. 
Oats . — The aleuron-layer is one cell thick as in Wheat ; 
and the grains show much the same degree of solubility. 
Zea Mays . — The aleuron-grains are smaller and less regular 
than those of Wheat. They appear to contain a small globoid, 
or more than one, which is surrounded by a peripheral mass 
of proteid too thick to be considered a membrane, and which 
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