208 DKOSERA ROTUNDIFOLIA. Chap. XI. 



leaves made by keeping them for a long time in 

 merely warm water is far less efficient. A decoction 

 of grass-leaves is less powerful than one of green j)eas 

 or cabbage-leaves. 



These results led me to inquire whether Drosera 

 130ssessed the power of dissolving solid animal matter. 

 The experiments proving that the leaves are capable 

 of true digestion, and that the glands absorb the di- 

 gested matter, are given in detail in the sixth chapter. 

 These are, perhaps, the most interesting of all my 

 observations on Drosera, as no such power was before 

 distinctly known to exist in the vegetable kingdom. 

 It is likewise an interesting fact that the glands of the 

 disc, when irritated, should transmit some influence 

 to the glands of the exterior tentacles, causing them 

 to secrete more copiously and the secretion to be- 

 come acid, as if they had been directly excited by 

 an object placed on them. The gastric juice of ani- 

 mals contains, as is well known, an acid and a fer- 

 ment, both of which are indispensable for digestion^ 

 and so it is with the secretion of Drosera. When the 

 stomach of an animal is mechanically irritated, it 

 secretes an acid, and when particles of glass or gther 

 such objects were placed on the glands of Drosera, 

 the secretion, and that of the surrounding and un- 

 touched glands, was increased in quantity and became, 

 acid. But, according to Schiff, the stomach of an 

 animal does not secrete its proper ferment, pepsin, 

 until certain substances, which he calls jDeptogenes, 

 are absorbed; and it apj^ears from my experiments 

 that some matter must be absorbed by the glands 

 of Drosera before they secrete their proper ferment. 

 That the secretion does contain a ferment which acts 

 only in the presence of an acid on solid animal 

 matter, was clearly proved by adding minute doses of 



