110 



while those allowed to remain in the propagating house were 

 examined daily. 



Dry Egg-white * 



Particles of dry white of egg were placed upon all the leaves 

 of a plant on October 13, 1907. The tentacles curved slowly but 

 at the end of 24 hours were tightly closed over albumen parti- 

 cles. At the end of three days the albumen had entirely dis- 

 appeared and was no doubt pretty thoroughly digested. 



In the use of such crude products as egg-white, as was the 

 case in practically all of Darwin's Drosera experiments, the pos- 

 sible influence of salts and other non-protein compounds in the 

 materials employed, is ignored. In the remaining experiments, 

 accessory substances, such as inorganic salts and extractives, 

 have had no influence, for they were completely eliminated from 

 the protein samples in the course of their preparation. 



ACIDALBUMIN 



Acidalbumin particles were placed upon all the leaves of a 

 plant on October 13, 1907, but the response was slight, and the 

 albuminate remained at the end of three days. 



Alkali Albuminate 



Alkali albuminate particles were placed upon the leaves of a 

 third plant, October 13, 1907, with a result similar to that in the 

 case of the acidalbumin. 



The results of the foregoing experiments show that egg 

 albumen causes a response of the tentacles and ultimate diges- 

 tion, while the acidalbumin and alkali albuminate both cause a 

 much less vigorous response. The plants upon which the experi- 

 ments were tried were just ready to enter the resting stage so it is 

 hardly fair to say that they would not more readily digest the 

 acidalbumin and alkali albuminate if the plants had been in prime 

 condition. It is possible, of course, that the prior separation of 

 saline matters and other impurities from the albuminates, re- 

 moved an effective digestive stimulus. 



* This was the only crude product employed. All others were chemically pure. 



