Vines. — Proteolytic Enzymes in Plants. 245 
In another experiment, the action of the fruit-tissue on Witte- 
peptone was observed. 5 grms. were placed in a bottle to which 
20 cc. of distilled water, and the same quantity of chloroform-water, 
with 0*3 grm. Witte-peptone, were added. After 19 hours’ diges- 
tion the liquid gave a distinct tryptophane-reaction. The liquid 
of a control-experiment, containing no Witte-peptone, gave no 
reaction. 
Lycopersicum esculentum. 
The expressed juice of the Tomato is turbid, reddish in colour, 
acid, and seems to give a tryptophane-reaction, but this is difficult to 
decide on account of the colour of the liquid. 
30 cc. of the juice were placed in each of three bottles : to No. 1 
nothing was added; to No. 2, 0-3 grm. of Witte-peptone and 0-3 cc. 
of 4 % HCN ; to No. 3, 0-3 grm. of Witte-peptone and 1-5 cc. of 4 % 
HC 1 (= o*i8 %). 
After 2 hours’ digestion, No. 1 gave a distinct tryptophane- 
reaction ; Nos. 2 and 3 a marked reaction, rather stronger in 3 than 
in 2 : after 22 hours’ digestion, No. 1 gave a marked reaction, No. 2 
a very strong, and No. 3 a strong reaction. 
Pyrus Malus. 
The not quite ripe apple used was a variety of Codlin. The 
expressed juice is a greenish, acid liquid, which turns bright yellow 
on the addition of chlorine-water, the colour gradually deepening to 
orange. 
After 23 hours’ digestion with some Witte-peptone, there was no 
definite tryptophane-reaction. I then tried an experiment with 
bruised pieces of the parenchyma of the fruit, but with the same 
negative result. I was, however, more successful with the peel 
or rind. 
3 grms. of rind were placed in each of two bottles with about 
40 cc. distilled water: to the one nothing was added, to the other 
0-3 grm. of Witte-peptone. After 19 hours’ digestion, the liquid in the 
bottle containing no Witte-peptone gave a bright yellow colour on 
the addition of chlorine-water, but no tryptophane-reaction : that in 
the bottle to which Witte-peptone had been added gave a distinct 
reaction. 
