Green . — On Vegetable Ferments . 107 
nature of the action was however not investigated, and we can 
say nothing more as to the various bodies formed in the 
digestion. Vines carried the work further by showing that 
the enzyme can be extracted from the walls of the pitcher by 
dehydration and subsequent treatment with glycerine. The 
action can only be detected when the ferment works in a 
faintly acid medium, about *2- per cent, of hydrochloric acid 
being best. Vines’ paper embodies further some experi- 
ments made upon the pitchers with the view of ascertaining 
in what condition the ferment exists in the pitchers when no 
digestion is provoked. To this point we shall return later. 
Krukenberg 1 obtained a similar ferment from the plasmo- 
dium of Aethalium septicum , one of the Myxomycetes. Be- 
sides peptone, he found a body resembling an albumose in 
the products of the digestion. 
These ferments appear to resemble very closely the pepsin 
of the stomach, and provisionally they must be classed with 
it. In the characters of their action, their intimate associa- 
tion with weak hydrochloric or other acid, and the materials 
they can dissolve, the resemblances are striking. At the same 
time it must be remembered that the various authors do not 
quote any very detailed account of the bodies formed during 
the action, leaving it therefore undetermined whether the 
power of the ferment is sufficient to split up peptone into 
amide-bodies. 
Trypsin. Of the tryptic group the ferment which was the 
first to be very completely examined is the so-called papain or 
papaine. It has long been the custom of the natives of India 
to cook certain fruits with tough meat to make it tender, and 
curious stories have obtained currency with respect to the 
powers of that of the Papau ( Carica Papaya ) in this connection. 
Wrapping tough meat in the leaves of the plant, or even hang- 
ing it under the tree has been said to have the same effect. 
Three such fruits in particular have been used for the purpose, 
the Papau, the Fig, and a variety of the Melon ( Cucumis 
utilissifnus ). 
1 Untersuch. aus dem physiol. Inst, der Univ. Heidelberg, Band II, Hft. 3, 1878, 
