612 Vines . — Proteolytic Enzymes in Plants (//). 
Turning now to the question of the proteolytic activity of 
the juice, I may mention that Buscalioni and Fermi found the 
tuberous roots of the Dahlia to be proteolytically inactive, 
but this is not in accordance with my results. I made 
experiments (a) with the juice alone (autolysis) ; ( b ) with 
Witte-peptone added ; ( c ) with fibrin added ; in all cases there 
was distinct evidence of proteolysis. The material used was 
the root in the resting condition, and the experiments were 
carried on at intervals from January to March. 
Auiolysis. 
40 cc. of slightly diluted expressed juice were placed in each of 
4 bottles: to (1) nothing was added; to (2) HCN 0-2 %; to (3) citric 
acid 0-5 % ; to (4) HCN 0-2 %, and citric acid 0-5 %. 
After 21 hours’ digestion at 40°C., the contents of (1) and (2) gave 
a distinct tryptophane-reaction, those of (3) and (4) a marked reaction. 
30 hours later, (1) and (2) still gave the same reaction, whilst that of 
(3) was marked, and that of (4) had become strong. 
Proteolysis of Witte-peptone . 
In each of four bottles were placed 50 cc. of expressed juice 
diluted with equal vol. of dist. water, and 0*5 grm. Witte-peptone: 
the further additions to the bottles were precisely as in the preceding 
experiment. 
After 4 hours’ digestion at 40°C., the tryptophane-reaction was strong 
in the bottle containing citric acid, and in that to which neither citric 
acid nor HCN had been added ; marked in the citric acid and HCN 
bottle; distinct in that to which HCN but no citric acid had been 
added. 
19 hours later, the reactions were essentially the same. 
Fibrin . 
4 bottles were prepared precisely as those in the preceding experi- 
ment, except that 1 grm. moist fibrin was substituted for the Witte- 
peptone. 
After 19 hours’ digestion at 40° C., the fibrin had become shrivelled 
and stringy in all the bottles, and did not appear to have been at all 
dissolved. The tryptophane-reactions were: — distinct in the citric 
acid and HCN bottle, as also in the bottle with HCN but no citric 
