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 

 or 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 



FIG. 94. MODIFIED LEAP (PITCHER) 

 OF Nepenthes. (After Kerner.) 



