268 DROSERA ROTUNDIFOLIA. Cuar. 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 peas 
or cabbage-leaves. 
These results led me to inquire whether Drosera 
possessed 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 detuil 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 other 
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 peptogenes, 
are absorbed; and it appears 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 
