1176 Stoward. — A myloclastic Secretory Capacities of the . 
paper. Unfortunately, if the experiment is continued beyond about four 
days, there is a decided tendency for the embryo to become detached from 
its inner endosperm, and this tends to limit the period of experiment. 
The inner endosperms in these experiments were carefully examined 
for starch grains exhibiting signs of erosive action. Repeated examination 
of specimens of the endospermic starch grains taken from various parts of 
the inner endosperm fail to reveal any eroded starch grains except in that 
part of the inner endosperm with which the exterior surface of the scutellum 
is in close contact. 
It is clear, therefore, as in experiments with isolated inner endosperms, 
so in these experiments, that there is an entire absence of the amylase 
resident in the amyliferous cells corroding the starch grains at its 
disposal, this mode of attack being, as already stated, confined to the 
amyloclastic secretions of the embryo and aleurone layer. 
XII. The Inactivation of the Amylase of Ungerminated 
Barley. 
The suggestion has frequently been put forward that either the active 
secretions or substances other than secretions which pass by diffusion from 
the epithelial and aleurone-layer cells during the germination process may 
possibly exercise an activating influence on the amylase pre-existent in the 
inner endosperm either in the condition of 4 free ’ or ‘ latent 5 enzyme. 
It therefore appears desirable to subject the question to experimental 
inquiry, more for the purpose of ascertaining what would happen than 
with the hope of acquiring any very definite indications of the nature 
of the changes induced. 
In the following essays the influence exercised by the embryo and 
aleurone-layer secretions on the amylase of resting barley has been made 
the subject of inquiry. The enzyme solutions used were derived from 
separate cultivations of embryos and aleurone layers on asparagin-mineral 
salt solution. The culture liquids containing the active amylase were 
removed aseptically with sterilized pipettes, which were at once sealed and 
afterwards conserved in the dark for 2-3 months prior to their use. 
TABLE XXXV. 
Influence of Embryo Secretion on the Amylase of 
Ungerminated Barley Substance. 
Digestion period, i hour at 30°C. Starch solution containing 58 grms. starch solids per 
100 c.c. of solution. 
^ X P' lent to mg. Cu. 
1. 5 c.c. embryo secretion + 30 c.c. starch solution 208 
2. 5 c.c. water + 30 cc. starch solution + 02 grm. barley 343 
3. 5 c.c. embryo secretion + 30 c.c. starch solution + o«2 grm. barley _ 556 
4. 5 c.c. embryo secretion +30 c.c. starch solution+ 0-2 grm. barley (boiled) 159 
5. 5 c.c. embryo secretion (boiled) + 30 c.c. starch solution + 0*2 grm. barley 310 
