428 MB. S. H. VINES ON THE 



cells a ferment similar in its properties to that which exists in the 

 peptic glands of animals. Accordingly, they proceeded to treat 

 the leaves of Brosera in the same way as the gastric mucous mem- 

 brane of an animal is treated when it is desired to prepare from 

 it a glycerin extract holding pepsin in solution, according to the 

 method of Von Wittich ; that is to say, they first treated the 

 leaves with absolute alcohol for twenty-four hours, to remove as 

 much water as possible from them, and then, after reducing them 

 to pulp, allowed them to stand in glycerin. They then proceeded 

 to test the digestive properties of this extract by placing in it 

 some shreds of swollen-up fibrin (prepared after G-riinhagen'a* 

 method) and acidifying it slightly with dilute hydrochloric acid. 

 They found that at the end of eighteen hours, at a temperature of 

 40° C, the fibrin had entirely disappeared, and that the filtered 

 liquid gave the characteristic peptone reaction when treated with 

 caustic potash and dilute copper sulphate. At the same time 

 they had carried on control-experiments with shreds of fibrin ex- 

 posed in the one case to the unacidified extract, in the other to 

 the dilute hydrochloric acid. In neither of these cases was the 



fibrin dissolved; nor did the filtered liquid give the peptone 

 reaction. 



From these experiments it is evident that the leaves oiDrosera 

 contain a digestive ferment which resembles that of the peptic 

 glands of animals— (1) in that it is soluble in glycerine, and (2) 

 in that it exercises a digestive action on proteids only in the pre- 

 sence of an acid, the result of this action being the conversion of 

 proteids into peptones. It cannot be doubted, therefore, that 

 the solution of proteids which was observed in the numerous 



by a process of true digestion. 



Mr 



Gorup 



Besanez f with reference to Nepenthes (phyllatnphora and gracilis), 

 though in this case the secretion itself was the subject of experi- 

 ment. He found that shreds of fibrin, placed in the secretion 

 (which had an acid reaction) were more or less completely dissolved 

 within an hour when exposed to a temperature of 40° C, and that 

 the filtered liquid gave the characteristic peptone reaction with 



. * This method consisted in soaking the fibrin in dilute HC1 (2 per cent.) 

 until it is quite gelatinous. 



t Beriehte der deutsch. chem. Geselkch. zu Berlin, Jahrg. 9, No. 9, May 22, 



1876. 



