1910. ] The Proteolytic Enzyme of Drosera. 139 
On application of the tryptophane test to the contents of the test-tubes 
C, D, G, H, K, and I, it was found that in none of the tubes could there be 
detected the faintest trace of amido bodies or of any digestion carried beyond 
the peptone stage, and the same result was obtained when the tubes had been 
put back into the oven for an additional 24 hours. 
The results of these additional experiments must consequently serve to 
strengthen my previous conclusion that the digestive process by the 
proteolytic enzyme present in the leaf glands of Drosera does not extend 
further than the production of peptones. 
In conclusion I wish to thank Prof. Ewart for all the help he has given 
me. Supplies of fresh material of the different species tested were obtained 
as they were required by Mr. J. W. Audas, of the National Herbarium. 
BIBLIOGRAPHY. 
Dubois, R., “Sur le prétendu pouvoir digestif du liquide de lurne des Nepenthes,’’ 
‘Compt. Rend.,’ 1890, vol. 111, p. 315. 
Reynolds Green, J., ‘The Soluble Ferments and Fermentation.’ 
Lawson Tait, ‘“ Insectivorous Plants,” ‘ Nature,’ 1875, vol. 12, p. 251. 
Tischutkin, “ Ueber die Rolle der Mikroorganismen bei der Ernihrung der Insecten- 
fressenden Planzen,” Abstr. in ‘ Bot. Cent.,’ 1892, vol. 50, p. 304, and 1893, vol. 53, 
p. 322. 
Vines, 8. H., “The Proteolytic Enzyme of Nepenthes,” ‘ Ann. Bot., 1897, vol. 11, p. 563. 
“The Proteases of Plants,” ‘Ann. Bot., Jan., 1910, vol. 24, p. 213. 
