1160 Stoward*—Amyloclastic Secretory Capacities of the 
Slow but complete liquefaction accompanied by the customary ‘ break ■ 
or separation of a flocculent material occurred in Experiments i, 2, 3, and 5, 
but in Experiment 4 these features were entirely absent. 
The iodine reaction was persistently blue throughout the course of the 
conversion. The method of predigestion failed to induce in the ‘ latent ’ 
enzyme the acquisition of those specific properties which differentiate 
■ secretion ’ amylase as a more or less distinct type of amylolytic enzyme. 
These starch-conversion experiments were not regarded as satis¬ 
factorily settling this point, and similarly conducted experiments, with the 
exception that the concentration of starch was lower, were undertaken in 
order to ensure the action of residual amylase attaining those final stages 
which are marked by the appearance of a persistent violet coloration with 
iodine. 
It has been definitely shown by Baker 1 that in starch-paste conversions 
with the amylase of ungerminated barley the reaction never goes beyond 
the violet coloration, and further that the conversion products formed by its 
action on starch paste are different from those formed by malt amylase in 
otherwise similarly conducted conversions. 
The view has been recently advanced by Ling 2 that digestive trans¬ 
formations of storage contents and organized structures (cell walls and 
cytoplasmic contents) of the inner endosperm are conditioned solely by 
enzymes residual in this tissue. In particular does this refer to digestive 
changes in the starch-storage reserves. The amylase, both ‘ free ’ and 
‘ occluded ’ or ‘ latent resident in the inner endosperm—according to Ling 
■—undergoes transformation into that of malted corn, i. e. the amylase of 
the resting grain (as the germinative process progresses) virtually acquires 
the properties of malt amylase, and it is further assumed that the process of 
transformation in the germinating seed under malting conditions is closely 
paralleled by that which takes place when resting barley is subjected to 
auto- or papain-digestion. 
In view of this suggestion it will be appropriate in this section to note 
the following experiment 
0-5 gramme of finely ground barley was predigested with 25 c.c. of 
1 % papain for twenty-four hours at 30° C, a small quantity of toluene 
being added as antiseptic. The extract thus prepared was filtered and 
20 c.c. of the clear filtrate were added to 50 c.c. of 4 % starch paste and 
digested successively for two and a half hours at 55 0 C., twenty hours at 
30° C., three hours at 55 0 C, and finally twenty-four hours at 30° C. 
The colour reactions with iodine at the termination of each successive 
digestion interval were respectively intense blue, intense violet, less intense 
violet, i. e. at the termination of the first interval blue, and a persistent 
intense violet during the remaining ones; the colour test being carried out 
1 Baker : Journ. Chem. Soc., Ixxxi, 1902, p. 1177. 2 Ling: Journ. Inst. Brewing, xiv, 190S. 
