OF INSECTIVOROUS PLANTS 449 



ceding experiment). The proteolysis was marked on the fourth day, and 

 was almost complete on the ninth day. 



Liquor from non-stimulated pitchers was used in all of the following 

 experiments. 



The liquor (0.6 cc.) was digested with 2 cc. of the globulin solution 

 0.5 cc. 0.1 N hydrochloric acid, and 1.9 cc. of water. No proteolysis 

 had occurred at the end of 14 days. 



In another experiment, 2.5 cc. of the liquor, 2 cc. of the substrate 

 solution, and 0.5 cc. 0.1 N hydrochloric acid were mixed and incubated; 

 the protean was completely digested in 14 hours. 



Two experiments were made, using 1 cc. of liquor, 2 cc. of the sub- 

 strate solution, 0.5 cc. 0.1 .Y hydrochloric acid, and 1 cc. of water. 

 The protean was almost completely digested in one of these experiments 

 in 29 hours, and was completely digested in the other experiment in 48 

 hours. 



It should be noted that liquor from a separate pitcher was used in 

 each experiment in which this protean served as the substrate. 



Jacoby^s Ricin 



This test was carried out with the reagents prescribed by Jacoby (23). 

 A solution of 1 gram of ricin (Jacoby) and 1.5 grams of sodium chloride 

 in 100 cc. of water was prepared, and filtered if necessary. The pitcher 

 liquor (1 cc.) and the ricin solution (3 cc.) were mixed; 1 cc. of 0.56 

 percent, hydrochloric acid was added; and the resulting mixture was 

 incubated. In the presence of a protease active in this concentration 

 of hydrochloric acid, the cloudy precipitate, which forms on the addition 

 of the acid, is dissolved during subsequent incubation. The reactions 

 involved are essentially the same as those described above for the castor- 

 bean globulin. 



Liquor from a stimulated pitcher was used in one experiment. The 

 cloudy precipitate underwent a marked proteolysis in two days. 



Liquor from a non ■stimulated pitcher was used in another experiment. 

 The cloudy precipitate was partially digested in two days, but had not 

 been entirely digested at the end of 1 week. 



Glycyltryptophane 



Liquor (10 cc.) from stimulated pitchers was incubated with 2 cc. 

 of an aqueous solution of the dipeptide, glycyltryptophane (so-called 

 Ferment diagnosticum). In this series of experiments only, toluene 

 was used as a bactericide. After incubation, the test for free trypto- 



