248 Vines . — Proteolytic Enzymes in Plants. 
further added 1 cc. of 4 % HCN; to No. 3, 0-3 grm. of Witte- 
peptone; to No. 4, 0*3 grm. of Witte-peptone and 1 cc. of HCN; 
in No. 5 the stem was boiled in the water before the addition of 
0-3 grm. of Witte-peptone. 
After 24 hours’ digestion. No. 4 gave a distinct tryptophane- 
reaction: the liquid in No, 3 had become so darkly coloured that 
it could not be satisfactorily tested : none of the others gave any 
reaction. 
Cucurbita Pepo var. ovifera . 
The shoots of the Vegetable Marrow yielded, on pressure, a con- 
siderable quantity of turbid, slightly acid, juice. Some of this was 
placed in each of four bottles: to No. 1, nothing was added; to 
No. 2, o*5 grm. of Witte-peptone; to No. 3, 0*5 grm. of Witte-peptone 
and o-2 grm. of citric acid; to No. 4, 0*5 grm. of Witte-peptone and 
HC 1 to o-2 %. After 22 hours’ digestion, Nos. 1 and 2 gave a 
faint tryptophane-reaction, No. 3 a marked, and No. 4 a distinct 
reaction. 
Mirabilis Jalap a. 
Three bottles containing expressed juice were treated as follows : 
to No. 1, nothing was added; to No. 2, 0*3 grm. Witte-peptone; 
to No. 3, 0-3 grm. Witte-peptone and 1 cc. of HCN. After 20 
hours’ digestion, No. 1 gave a faint, and Nos. 2 and 3 a distinct 
tryptophane-reaction. 
Similar results were obtained with Helianthus tuberosus. 
Cuscula , sp. 
The special interest of this experiment lies in the fact that the 
plant is a parasite, and that its leafless shoots contain no chlorophyll. 
A quantity of the shoots of a species, in flower, growing on some 
plants of Artemisia, was ground up fine: 40 grms. of this material 
were extracted with 40 cc. of distilled water. On pressure, a dark- 
brown acid liquid was obtained, which gave no tryptophane-reaction. 
20 cc. of the unfiltered liquid were placed in each of two bottles : 
to each a few drops of 4 % HCN were added, and to one of them 
(2), 0*5 grm. of Witte-peptone. 
After 20 hours’ digestion, bottle No. 1 gave no tryptophane- 
reaction : bottle No. 2 gave a distinct reaction. 
