38 
pitcher. Plants now growing in the Garden will be utilized 
later for a study of the properties of the pitcher fluid. 
Two quantities of Sarracenia from different localities have thus 
far been placed at my disposal by Dr. MacDougal. Glycerin 
extracts of the thoroughly macerated tissue of one set of plants 
showed moderate though distinct digestive action on fibrin at 
38° C. in the presence of slight amounts of hydrochloric or 
oxalic acids, the control experiments giving negative results, 
of the extracts of the second set of plants, however, were 
entirely without digestive action. 
In view of the negative results in the second series it is im- 
possible at present to draw a satisfactory conclusion in this con- 
nection. It may be that the positive results in the first case were 
due to a bacterium specially favored by the medium furnished by 
the constituents of the glycerine extract, or to enzyme in unob- 
served diseased portions of the plants. Again, the negative re- 
sults may have been due to a less favorable degree of acidity, or 
the secreting cells of the pitchers may have been in a “resting 
condition,” without either enzyme or zymogen. Further ex- 
periments, with these matters controlled, and on pitchers gath- 
ered at a more favorable season, will surely settle these questions. 
e growing plants in the Garden will also be used for direct 
determinations of the influence of putrefactive products introduced 
into the pitcher fluid. 
n the course of the digestive experiments I had occasion to 
try the activity of the extracts under neutral, acid and alkaline 
conditions. Observing that the diluted neutral extract was prac- 
tically colorless, the acid mixture crimson and the alkaline fluid 
green, I made a few tests to determine the significance of the 
colorific effects. 
These tests resulted in showing that Sarracenia purpurea coD- 
tains a pigment which in concentrated glycerin extract has a 
reddish color, but which when diluted is practically colorless. 
At such dilution, when scarcely any color is to be seen, a drop 
of dilute acid produces a bright pink throughout the whole fluid; 
alkali in minute amounts turns it green. The pink is converted 
to green by alkali, evce versa by acid. Even in crude glycerin 
