568 Vines . — The Proteolytic Enzyme of Nepenthes. 
neutral liquid ; a wasp which made its way into it soon died, 
and the liquid acquired an alkaline reaction, many Bacteria 
and Infusoria being present in it. The second pitcher con- 
tained acid liquid, in which there was a fly : the liquid 
dissolved fibrin in an hour, and after three hours it contained 
no dissolved albumen, but only peptone; another shred of fibrin 
was dissolved by the liquid in forty minutes at a temperature 
of 1 6-1 8° C., when some o*2°/ o solution of hydrochloric acid 
had been added to it ; a gelatin-culture from this liquid 
gave no indication of the presence of Bacteria. The youngest 
pitcher was still closed : it contained 4*6 c.cm. of a neutral 
viscid liquid : a gelatin-culture from the liquid gave no 
indication of the presence of any Fungi ; on the addition of 
formic acid to the extent of -ooi, a shred of swollen fibrin 
was dissolved by it in twelve hours. Goebel did not succeed 
in preparing an active glycerin-extract of the pitchers. He 
concludes that these facts suffice to invalidate the assumption 
that the digestive process which, goes on in the pitchers is to 
be attributed to the action of Bacteria, which only comes into 
play in the case of old and exhausted pitchers, the liquid 
in which has no longer an acid reaction. 
In view of Goebel’s observations, it may perhaps seem 
superfluous to reopen the subject : but inasmuch as the 
statements of Dubois and of Tischutkin are in direct con- 
tradiction to my own published results, I have felt it necessary 
to repeat my experiments, and to extend and modify them 
in various directions. I hope that the new facts which 
I am now able to bring forward may be accepted as my 
justification. 
Goebel has already commented upon the insufficiency 
of Dubois’ data as a basis for the sweeping conclusions which 
he draws : but there is one point to which I would draw 
special attention. One of the most important pieces of 
evidence upon which Dubois relies is the fact that liquid 
drawn directly from unopened pitchers exerted no digestive 
action upon cubes of white of egg. It is to be remarked 
that he himself describes the liquid in unopened pitchers as 
