OF INSECTIVOROUS PLANTS 423 



from stimulated pitchers imparted a decidedly red color to litmus paper, 

 and the color did not completely vanish on exposure to the air. 



Liquor from Stimulated Pitchers 



The insect residues were removed by filtration, and the action of the 

 filtrate on certain substrates was studied. Ox-blood fibrin was swollen 

 to a gelatinous mass in 0.2 percent hydrochloric acid, then was freed as 

 completely as possible from the adherent acid by means of pressure. A 

 flock of this fibrin was almost completely dissolved by the pitcher liquor 

 in ^ to 1 hour at a temperature of incubation of 40° C, and in 2 hours at 

 a temperature of incubation of 20° C. The resulting solution was 

 faintly opalescent. The time required for solution of the fibrin was 

 reduced to 14: hour by addition of several drops of 0.2 percent hydro- 

 chloric acid to the liquor. After digestion for two hours, the filtered solu- 

 tion remained clear on boiling, and was not precipitated by mineral acids 

 or by acetic acid plus potassium ferrocyanide, but was precipitated by 

 mercuric chloride, by tannin, and by phosphotungstic acid, and gave an 

 excellent rose-red biuret reaction. 



Little slices of coagulated egg white were digested with liquor to which 

 1 or 2 drops of 0.2 percent hydrochloric acid had previously been added. 

 After 24 hours at 20° C, the sUces were attacked at the edges, and were 

 transparent; the filtrate from them gave a distinct rose-red biuret reaction. 



On digestion at 20° C. with pitcher liquor and 1 or 2 drops of 0.2 per- 

 cent hydrochloric acid, raw meat soon became transparent at the edges 

 and somewhat swollen, and was partly dissolved without putrefaction. 

 A further change was not noted after 48 hours. The filtered solution 

 was not precipitated by boiling, nor by the addition of acetic acid and 

 potassium ferrocyanide, was precipitated by mercuric chloride and by 

 tannin, yielded a cloudy precipitate with phosphotungstic acid soluble in 

 excess of the reagent, and gave a positive biuret reaction. 



Legumin became transparent on the edges and somewhat swollen 

 after digestion for 24 hovu-s at 20° C. with pitcher liquor plus 1 or 2 drops 

 of 0.2 percent hydrochloric acid; the filtered solution gave a very decided 

 biuret reaction. 



Gelatin, upon which pitcher liquor plus several drops of 0.2 percent 

 hydrochloric acid had been poured, dissolved almost completely after 

 24 hours at ordinary temperature. The solution was filtered and con- 

 centrated to a small volume; it did not gelatinize, but remained a thick 

 syrup; digestion had occurred with the production of gelatin-peptone, 

 and the power to gelatinize had been destroyed. 



