117 
1913-14.] Enzymatic Peptolysis in Germinating Seeds. 
the Buchner mortar. A suitable quantity of Pepton Roche solution was 
then added and the resulting mass subjected to a pressure of 300 kg. per 
sq. cm. in the Buchner press. The expressed liquid was freed from sus- 
pended particles by means of the centrifuge, and then passed through a 
Chamberland filter into sterilised Pasteur flasks, which were afterwards 
placed at the same temperatures as were employed before. 
The results obtained from this experiment were similar to those 
obtained before with regard to the separation of tyrosin — a strongly 
marked reaction at 25° and 37°, a less marked but distinct reaction at 15°, 
and no reaction at 50°. 
Part of the contents of the flask which had been incubated at 25°, and 
which had given the heaviest deposit of tyrosin, were transferred to a 
Pasteur flask containing sterilised glucose-Pepton Witte solution and further 
incubated at 25°. The contents of the flask were found to remain sterile 
throughout the whole period of incubation, which extended over several 
weeks, proving conclusively that the peptolysis was not due to any 
development of micro-organisms. 
The presence in germinating barley of two distinctly different peptases 
having be,en thus established, the next step in the main research became 
that of ascertaining at what period the activation of the above-mentioned 
peptases takes place, in order that the conditions influencing the activation 
might be finally studied in detail. 
For the purpose of elucidating this point, the peptolytic activity was 
determined from time to time in a sample of barley during germination 
and the results confirmed, firstly, with another quantity of the same sample, 
and secondly, by repeating and extending the experiment with a different 
sample. 
The examination was in each case commenced with the ungerminated 
barley, and was continued in the first two instances for seventeen days, in 
the last instance for twenty-nine days. The germination took place under 
the conditions usually observed in the preparation of malt, and the samples 
were examined at intervals of from two to four days. 
The water content was determined in every sample withdrawn for 
examination, by placing 5 grms. of the ground material in a weighing 
bottle, covering it with absolute alcohol, and drying it in a hot- water oven 
for twenty-four hours. 
500 grms. of barley were disintegrated in a mincing machine and 
ground in a Buchner mortar with 500 grms. of sand and a suitable quantity 
of water to make a firm paste. This was placed in a Buchner press and 
subjected to a pressure of 350 kg. per sq. cm. for about one hour, when no 
