828 Stoward.—Amyloclastic Secretory Capacities of the 
aleurone layer, possess of augmenting their amylase content. The salient 
point of difference to be noted is that under precisely parallel external 
conditions and quite apart from any possible differences in the attributes 
of the amylase from the two available sources (aleurone layer and inner 
endosperm), the amounts of enzyme which have diffused from the objects 
into the culture medium and naturally the total amounts of enzyme in 
objects and medium in Experiments 1, 2, 3 (endosperms) are decidedly 
superior to those in Experiments 4, 5 (inner endosperms). 1 
If certain provisional assumptions are made, certain tentative evaluations 
of the relative augmentative capacities of the endosperm and inner endosperm 
under the selected conditions of experiment may be formed. These are 
that (1) destruction of enzyme falls equally on the enzyme from either 
source ; (2) both enzymes have similar properties or attributes; (3) in both 
series of experiments the inner endosperm comports itself in precisely the 
same manner as regards its enzyme augmentative capacity, i.e. the presence 
of the aleurone layer does not influence the augmentative capacity of the 
inner endosperm ; in short, the inner endosperm retains its individuality. 
Then, from the data given in Table XII, an approximate calculation may 
be hazarded of the relative augmentative capacities of the endosperm, inner 
endosperm, and of the aleurone layer. 
The total augmentation of enzyme in each experiment is readily arrived 
at by deducting the initial amylase content from the total amylase content. 
Thus in Experiments 1 and 4 we have:— 
Exp. 1. 3664 — 1181 = 2483 mg. 
Exp. 4. 1904 — 844 = 1060 mg. 
The relative contributory shares of the aleurone layer and inner endo¬ 
sperm may be computed by deducting the augmentation of enzyme in the 
inner endosperm from the augmentation in the endosperm. Thus in 
Experiments 1 and 4 we have :— 
2483 — 1060 = 1423 mg. 
For the convenience of survey these results are given in tabulated form. 
1 These experiments afford clear evidence of the diffusibility of one colloidal substance into 
another (see Brown and Morris, Chemistry and Physiology of Foliage Leaves, Journ. Chem. Soc., 
lxiii, 1893, p. 657). Diffusion of enzyme across the aleurone layer cell-walls and spermoderm prob¬ 
ably only takes place to a very limited extent. In Experiments 1 and 2 (endosperms), therefore, the 
enzyme must pass principally if not wholly via the ‘ germ bed ’ or exposed proximal end of the 
amyliferous tissue. Although the conditions in Experiments 4 and 5 (inner endosperms) for outward 
diffusion of enzyme apparently are greatly improved by removal of the aleurone layer, yet the amount 
of enzyme found in the medium is (as compared with Experiments 1,2, 3) considerably less. The 
result is hardly that which anticipation would lead one to expect, if the units of the inner endosperm 
and aleurone layer possessed equal capacities for augmenting their content of amyloclastic enzyme. 
Apart from the provision of external conditions favourable to outward diffusion, however, as we 
shall see later, the presence of a cytoclastic enzyme in the endosperm modifies certain internal 
conditions which probably favour diffusion. Removal of the aleurone layer means elimination of 
one of the principal sources of this cytoclastic enzyme. 
