187 



Experiments 



The present series of experiments was undertaken under the 

 direction of Professor WilHam J. Gies, at the New York Botan- 

 ical Garden, in the summer and autumn of 1907, in order to de- 

 termine especially the digestive power of Sarracenia purpurea on 

 carbohydrates, fats, and proteins. 



The plants were obtained from the sphagnum bogs near Lake- 

 wood, N. J., and from a similar locality near Poughkeepsie, N. 

 Y. No difference was observed in the behavior of the plants 

 from the two localities. They were planted in sphagnum and 

 kept in the propagating houses of the New York Botanical Gar- 

 den under as nearly natural conditions of temperature and mois- 

 ture as possible. Before a solution was placed in a pitcher the 

 contents were withdrawn by means of a pipette, the pitcher was 

 thoroughly, though gently rinsed with tap-water and distilled 

 water, and swabbed with absorbent cotton. After the solu- 

 tion had been placed in the pitcher, it was covered with lace 

 net which proved effectual in preventing the entrance of in - 

 sects except during the use of olive oil, which was so attractive 

 to ants that it was necessary to set the crocks containing the 

 plants used for those experiments in dishes containing water to 

 keep the ants out. The materials used in the protein tests were 

 prepared under Professor Gies's personal supervision and great 

 care was taken in handling the others. 



Tests were made of the effects of various solutions with the 

 special purpose of providing helpful information for use in the 

 subsequent digestive work. 



I. Effects of Various Solutions 



Acetic Acid. — A 0.5 per cent, solution of acetic acid was 

 found to be injurious. Pitchers containing it began to wither 

 above the level of the liquid within a few hours, and were dead 

 at the end of six days. 



Potassium Nitrate. — A dilute solution of potassium nitrate 

 {in\\02\) proved harmless, though by frequent renewals it was 

 kept in the pitchers a period of six weeks. A 0.5 per cent, so- 

 lution of potassium nitrate was not injurious. In one case per- 



