200 Green . — On the Occurrence of Vegetable Trypsin 
The association with a globulin would also be suggested 
by the observation already mentioned, that on boiling, the 
extract became turbid from the presence of coagulated 
proteid. 
The most powerful proteo-hydrolytic ferment that has 
hitherto been found in plants is the vegetable trypsin occur- 
ing in the Papau, which has been carefully worked out by 
Martin h The gourd under examination appearing to resem- 
ble this fruit in many respects, experiments were next under- 
taken to see if the two ferments also are alike. The points 
investigated were (i) the medium in which the Cucumis- 
ferment is most active, (f) the products of the decomposition 
which it initiates. 
An extract prepared by salt solution from the pericarp, and 
one obtained by similar treatment of the central pulp in which 
the seeds were embedded, were carefully neutralised. Three 
tubes of each were prepared — one contained the extract 
diluted with an equal volume of % H. Cl., one the same 
with an equal volume of water, and the third the same with an 
equal volume of 3 °/ 0 Na. 2 Co. 3 . Boiled controls of all were 
exposed side by side with them. To each was added a 
measured quantity of the egg-albumin, and the two sets with 
their controls were put side by side in an incubator at 34 0 C. 
They were labelled E x E 2 E 3 and F x F 2 F 3 , and their controls 
E lb F l6 , &c. The digestion was in this case continued for 
three days. During the experiment and at its conclusion the 
greatest activity was found to be shown by the alkaline tubes 
of both sets, while the acid had least power. Like papain, 
therefore, the ferment acts most advantageously in a faintly 
alkaline medium. 
The products of the decomposition were examined in a 
digestion carried out in dialysing tubes, controls being used, 
in which the extract was boiled before adding the albumin. 
These may be referred to as G and H. After twenty-four 
hours peptone was found to be present in the dialysate of G in 
1 Op. cit. 
