220 O' B Hen. — The Proteids of Wheat . 
amount of soluble matter yielded by bran depending on the 
fineness to which it is ground. Thus the nutritive value of 
bread containing bran, must depend, not on the absolute 
amount of nitrogenous matter present, but on the degree in 
which it is accessible to the action of liquids. For though the 
nitrogenous matter is not ordinarily available for nutrition, 
there is no reason to suppose that it is, in its nature, useless 
for this purpose, as has been urged (Poggiale 2 and others). 
The A leuron-L ayer during Germination. — ■ After being 
soaked in water for two days, wheat was sown, and later, 
examined at intervals. After one day the grains in the 
aleuron-layer did not seem to be affected, nor did those on 
the convex side of the grain after four days ; whilst those 
from the grooved face showed greater solubility than the 
former, and in some cases seemed already dissolving from 
within. 
After eight days, when the plumule is above ground and 
long adventitious roots are present, the aleuron-grains still 
persist ; but by the nineteenth only the membranes of the grains 
persist, and no mineral (Ca) is present in the aleuron-cells. At 
this time only a small part of the endosperm seems to have 
been used, but the starch-grains immediately under the aleuron- 
layer are much corroded. 
Function of the A leuron-L ayer. — ( i ) The aleuron-layer is 
frequently considered chiefly as a part of the reserve store for 
the embryo. 
(2) A conducting function (of diastase from the embryo) 
has also been suggested. 
(3) It is usually considered to be concerned in the diastatic 
solution of starch (Johanssen 10 ), whether by actual secretion 
of diastase (Haberlandt n , &c.) or, as just mentioned, by con- 
duction. This is also the general opinion among bakers, the 
aleuron-layer of bran (cerealin-cells) being supposed to exert 
a diastatic action on flour, shown in ‘ softening 5 of the dough 9 . 
(4) The presence of a gluten-transforming ferment is sug- 
gested by Balland 8 . 
The diastatic function of the aleuron-layer has been denied 
