Vines . — The Proteases of Plants {IV). 115 
In a subsequent paper (3) it was shown that extract of Green Peas ( Pismn 
sativum) acts strongly on Witt e-peptone ; and that the £ germ ’ of Wheat 
not only acts upon Witte-peptone, but also digests fibrin. My last paper on 
proteases (5) contains an account of more detailed investigation of the 
proteolytic properties of Malt, carried on with the object of elucidating 
the nature of the enzymes which effect not only peptolysis but also 
peptonization. 
I begin with a general description of the methods adopted. The seeds, 
as a rule without their integuments, were ground in a hand-mill : in nearly 
every case 10 grms. of the flour were triturated with 100 c.c. distilled 
water (10 °/ o mixture) : the mixture was generally used as such, but in 
some cases it was allowed to settle and the supernatant liquid decanted 
off: the antiseptic was HCN o-i °/ o : the ox-fibrin had been preserved 
in a mixture of dilute glycerin ($0 °/ o ) and alcohol, and was well 
washed before an experiment : the mixtures for digestion were put into 
stoppered bottles to prevent loss by evaporation, more especially of the 
HCN, a few drops of which were added from time to time when the 
experiments were protracted : the temperature of the incubator was about 
40° C. The fibrin was suspended in the digesting mixture by a thread, so 
that it could be readily examined from time to time. The fibrin used 
was of the same stock throughout the whole of the experiments ; the 
fact that in many instances the fibrin was not digested, suffices to remove 
any suspicion of self-digestion. 
The seeds employed were those of the following plants - Vicia Faba 
(Broad Bean), Pisum sativum (Pea), Phaseolus multiflorus (Scarlet Runner), 
Phaseolus vulgaris (White Haricot Bean), Lupinus hirsutus (Blue Lupin), 
and Zea Mais (Maize). The idea was to compare a number of more or 
less closely allied seeds, in this case Leguminous, introducing an altogether 
different one by way of contrast. In every case it was ascertained that 
the sample of seed used was capable of germinating. The seeds were 
germinated in a hot-house. 
The experiments were designed to determine whether or not (1) auto- 
lysis, or (2) fibrin-digestion, took place in the various mixtures. 
(1) Germinated Seeds. 
Vicia Faba. 19 days after sowing: 30 grms. of ground cotyledons extracted 
for 48 hours with 100 c.c. distilled water, at room-temperature : the extract gave 
marked tryptophane-reaction: 40 c.c. of the extract decanted off digested 0-2 grm. 
fibrin within 24 hours in the incubator. 
Phaseolus multiflorus. 7 days after sowing: 10% mixture gave distinct trypto- 
phane-reaction, which became strong after 24 hours in the incubator: the fibrin 
(°-3 g rrn *) had begun to break up after 72 hours, and had entirely disappeared 
in 120 hours. 
50 grms. of the same cotyledons were triturated with 200 c.c. distilled water and 
I 2 
