190 VEGETABLE PHYSIOLOGY 
definite digestive fluid possessing properties like those of 
the secretions of the stomach and pancreas of the higher 
animals by the instrumentality of which the insoluble 
proteins of their prey are converted into peptones, and 
possibly partially into amino- and amido-acids, prior to 
actual absorption. Among 
these Nepenthes may be men- 
tioned. 
The pitchers of Nepenthes 
(fig. 94) are in the main 
similar to those of Sarra- 
cenia. They possess means of 
attracting insects to them, of 
seducing them into the in- 
terior of the pitcher, and of 
preventing their subsequent 
escape, all of which are com- 
parable to those already de- 
scribed. The pitchers contain 
a watery liquid, which is 
secreted by their interior 
surfaces, and which has a 
faintly acid reaction. When 
an animal is captured and 
falls into the liquid, it sets 
up a further secretion, which 
is more strongly acid, and 
which contains a_ peculiar 
body known as an enzyme 
Fic. 94.—Mopiriep Lear (PircuEr) . 
oF Nepenthes. (After Kerner.) OF ferment, the properties of 
which will be discussed in a 
subsequent chapter. This ferment somewhat closely re- 
sembles the active principles of the gastric and pancreatic 
juices of the human body, and in the acid medium is capable 
of converting the proteins of the prey into peptone, leucin, 
and tyrosin, products which are all soluble and diffusible. 
This secretion is prepared by special glands, which are 
