OF INSECTIVOROUS PLANTS 461 



control experiment was made in which 2.5 cc. of physiological salt solu- 

 tion were s\ibstituted for the solution derived from the larvae. Carmine 

 fibrin (0.2 gram, weighed, then swollen in 0.2 percent hydrochloric acid) 

 was added to both the experiment proper and the control, and both were 

 then incubated at room temperature. In the control, the carmine 

 fibrin was completely dissolved in 1.75 hours. In the experiment proper, 

 the carmine fibrin was not dissolved at the end of 12 days, but had been 

 completely dissolved at the end of 17 days. Therefore antipepsin, 

 an antiprotease, was present in the larvae, since the solution derived 

 from the larvae markedly retarded the peptic digestion. 



In the second series of experiments, 82 larvae (total weight 8.30 

 grams) were used. From the same gathering of larvae a number were 

 bred to the adult fly, and proved, by examination of the male genitalia, 

 to be Sarcophaga sarraceniae Riley, the first recognized Sarcophaga asso- 

 ciate of Sarracenia. The larvae were ground with glass powder to an 

 intimate mixture, which was thoroughly triturated with distilled water. 

 The pasty mass was subjected to a pressure of 50 kilograms per square 

 centimeter in a Buchner press; 48 cc. of press juice were obtained. The 

 press juice was so cloudy that the edestan and casein tests could not 

 be applied in the examination for antiproteases, and only carmine fibrin 

 was used as a substrate. 



Antipepsin. In the experiment proper, 12 cc. of press-juice and 12 

 cc. of a freshly prepared 0.2 percent aqueous solution of pepsin were 

 mixed and allowed to stand at room temperature for .30 minutes to per- 

 mit the pepsin and the antipepsin (if present) to combine. Suflficient 

 hydrochloric acid (2 percent) and trikresol (2 percent aqueous solution) 

 were then added to make the concentration of each 0.2 percent in the 

 resulting solution; lastly, 0.2 gram of carmine fibrin was added. A con- 

 trol experiment vvas carried out in exactly the same manner as the ex- 

 periment proper, save that 12 cc. of distilled water were substituted 

 for the press-juice. The temperature of incubation was that of the room. 

 In the control experiment, the carmine fibrin was completely dissolved 

 in 45 minutes; in the experiment proper, it was partly dissolved in 14 

 hours and completely dissolved in 17 hours. 



Antitrypsin. In the experiment proper, 12 cc. of press-juice and 12 cc. 

 of a freshly prepared 0.2 percent aqueous solution of pancreatin (owing 

 its proteolytic power to trypsin) were mixed, and held at room tem- 

 perature for 30 minutes to permit the trypsin and the antitrypsin (if 

 present) to combine. Sufficient 4 percent solution of sodium carbonate 

 and 2 percent solution of trikresol were added to make 0.4 percent of 



