The Proteolytic Enzyme of Nepenthes (III). 
BY 
S. H. VINES, M.A., D.Sc., F.R.S. 
Sherardian Professor of Botany in the University of Oxford. 
HE occasion of my reversion to this subject is the publiCa* 
i tion of researches by the late Georges Clautriau (2) which 
were concluded but a short time before his lamented decease. 
The paper is of such importance, and is moreover so relatively 
inaccessible to English readers, that it will not be out of 
place if I give a short account of its contents. 
Clautriau was, I believe, the first to investigate the physio- 
logy of the pitchers of Nepenthes in the native habitat of the 
plant. The species which he so studied was N. melamphora , 
growing at a height of 1500-2200 metres near the laboratory 
which has been erected at Tjibodas on Mount Gedeh, a 
volcano in the island of Java. The proteid material used in his 
digestion-experiments was a 10 per cent, solution of egg- 
albumin rendered incoagulable on boiling by the addition of 
a small quantity of ferrous sulphate. In consequence of the 
altitude at which the experiments were performed, the tem- 
perature never exceeded 28° C. : digestion was therefore slow, 
and the experiments prolonged. 
The liquid in the unstimulated pitcher was found to be 
colourless, tasteless, almost odourless, and slightly viscid. On 
stimulation of the pitcher, the liquid became acid ; and when 
digestion had taken place, it acquired an odour resembling 
[Annals of Botany, Vol. XV. No. LX. December, 1901.] 
Pp 
