1 1 6 Vines — The Proteases of Plants (IV). 
left to stand at room-temperature for 24 hours : 150 c.c. liquid were then decanted off, 
and gave distinct tryptophane-reaction : the fibrin (0-3 grm.) remained unaltered 
until the seventh day in the incubator, when it was seen to be breaking up, the 
tryptophane-reaction being strong : the fibrin had disappeared on the ninth day. 
Same crop, 13 days after sowing: the 10% mixture of the cotyledons gave 
marked tryptophane-reaction : after 24 hours in the incubator, the fibrin (0-3 grm.) 
was partly digested, and the tryptophane-reaction had become strong : 2 1 hours 
later, the fibrin had completely disappeared. 
Pisum sativum. 6 days after sowing : epicotyls about 1 inch above the soil : the 
10 % watery mixture of the ground cotyledons gave marked tryptophane-reaction : 
after 24 hours in the incubator, the tryptophane- reaction had become strong : the 
fibrin (0*3 grm.) remained apparently unaltered until 72-96 hours in the incubator, 
when it was found to be attacked : 48 hours later it had disappeared. 
Some seedlings of the same crop were left to grow for 5 days more : a 20 % 
watery mixture of the cotyledons was then made, which gave strong tryptophane- 
reaction, and digested 0-3 grm. fibrin within 24 hours. 
Lupinus hirsuius. 4 days after sowing : radicles 1-2 inches long : 10 % mixture 
gave faint tryptophane-reaction : after 24 hours in the incubator, the tryptophane- 
reaction had become strong : after 1 20 hours, the fibrin (0-3 grm.) remained 
apparently unaltered, but had quite disappeared at the end of 168 hours. 
Same crop, 7 days after sowing : 10 % mixture gave distinct tryptophane- 
reaction, which had become strong after 24 hours in the incubator: the fibrin was 
found to be breaking up after 72 hours, and had disappeared by the end of 120 hours. 
Same crop, n days after sowing: cotyledons green: the 10% mixture gave 
faint tryptophane-reaction : after 48 hours in the incubator the tryptophane-reaction 
was found to have become strong and the fibrin to be breaking up : by the end of 
96 hours, the fibrin had disappeared. 
Phaseolus vulgaris. 8 days after sowing : the epigeal cotyledons were green : 
10 % mixture gave faint tryptophane-reaction : after 48 hours in the incubator the 
tryptophane-reaction had become strong, and the fibrin (0*3 grm.) was breaking up : 
within 72 hours the fibrin had disappeared. 
Zea Mais. 4 days after sowing : radicles well developed : ground up entire 
grains and seedlings: the 10% mixture gave distinct tryptophane-reaction: after 
24 hours in the incubator both the tryptophane-reaction and the fibrin (0-3 grm.) 
were unaltered: 24 hours later the tryptophane-reaction was marked, and most of 
the fibrin had gone : 24 hours later the fibrin had disappeared. 
The results of these experiments are altogether harmonious. In all 
cases it was found that, after germination, 
(1) the cotyledons, or the entire grain (Maize), contained tryptophane ; 
(2) the amount of tryptophane rapidly increased during the experi- 
ment ; and, 
(3) fibrin was more or less rapidly digested. 
The conclusions to be drawn are obviously these. (1) There was 
present in these germinated seeds an enzyme that produced tryptophane 
