1 59 
Vines . — The Proteases of Plants {II). 
Hence it appears that peptolysis is effected readily by the tissue itself, 
whether the reaction be acid or neutral, whilst extracts may be inert. It 
should be added that I failed to detect any digestion of fibrin, whether 
extracts or tissue were used ; so that this leaf, like so many others, seems 
to contain only erepsin. 
Phytolacca decandra. 
The interest attaching to the observations on the leaves of this plant is 
that they afford the first instance of fibrin-digestion by ordinary foliage- 
leaves, as distinguished from the leaves of carnivorous plants (. Nepenthes , &c.), 
on the one hand, and the leaves of laticiferous plants (e. g. the Fig) on the 
other 
70 grms. of fresh leaves were minced with the machine and were extracted with 
150 c.c. distilled water containing 1 % toluol for 22 hours : the liquid was then strained 
off through muslin : 40 c.c. liquid were placed in each of four bottles, to which was 
added — No. 1, nothing; No. 2, \ grm. Witte-peptone; No. 3, \ grm. casein; No. 4, 
0-2 grm. fibrin. 
After 2 1 hours’ digestion the fibrin had disappeared in No. 4. The tryptophane- 
reactions were — in No. 1, distinct; No. 2, strong; No. 3, marked; No. 4, distinct. 
In another similar experiment, 50 c.c. of leaf-extract digested \ grm. fibrin within 
48 hours, the liquid then giving strong tryptophane -reaction. 
Ficus Carica. 
It is well known that the latex of the Fig digests proteids (see my 
paper 8) : but I thought that the investigation of the leaves from this point 
of view might yield interesting results, especially if experiments were made 
at different times of the year. 
The first experiment was made on June 4, when the leaves were young, 
and did not seem to contain any milky latex. 
Experiment 1. 60 grms. fresh leaves were minced with the machine, the 
material being then extracted for a short time with 200 c.c. distilled water, containing 
1 % toluol. 50 c.c. of the strained liquid were put into each of two bottles : to the one 
was added \ grm. of fibrin, to the other \ grm. of casein. At the end of 48 hours in 
the incubator the fibrin remained unaltered, and neither bottle gave any tryptophane- 
reaction. 
The second experiment was made on August 11, when the leaves con- 
tained latex abundantly ; digestion was then rapid. 
Experiment 2. 90 grms. of leaves were extracted with about 200 c.c. distilled 
water with toluol 1 %. 50 c.c. of the strained liquid were put into each of two bottles ; 
to the one was added grm. fibrin, to the other \ grm. Witte-peptone. 
After 23 hours' digestion the fibrin had disappeared in the one bottle, and the 
contents gave strong tryptophane-reaction ; the contents of the other bottle also gave 
a strong reaction. 
