TRANSACTIONS OF THE SECTIONS. 113 
extent, even after the pitcher has been removed from the plant. I do not find that 
placing inorganic substances in the fluid causes an increased secretion, but I have 
twice observed a considerable increase of fluid in pitchers after putting animal 
matter in the fluid. 
To test the digestive powers of Nepenthes I have closely followed Mr. Darwin’s 
treatment of Dionea and Drosera, employing cubes of boiled white of egg, raw 
meat, fibrine, and cartilage. In all cases the action is most evident, in some sur- 
prising. After twenty-four hours’ immersion the edges of the cubes of white of egg 
are eaten away and the surfaces gelatinized. Fragments of meat are rapidly re- 
duced ; and pieces of fibrine weighing several grains dissolve and totally disappear 
in two or three days. With cartilage the action is most remarkable of all; lumps 
of this weighing eight and ten grains are half gelatinized in twenty-four hours, and 
in three days the whole mass is greatly diminished, and reduced to a clear trans- 
parent jelly. After drying some cartilage in the open air for a week, and placing 
it in an unopened but fully formed pitcher of NV. Rafftesiana, it was acted upon 
similarly and very little more slowly. 
That this process, which is comparable to digestion, is not wholly due to the 
fluid first secreted by the glands, appears to me most probable; for I find that very 
little action takes place in any of the substances placed in the fluid drawn from 
pitchers and put in glass tubes; nor has any followed after six days’ immersion of 
cartilage or fibrine in pitchers of N. ampullaria placed in a cold room, whilst on 
transferring the cartilage from the pitcher of N. ampullaria in the cold room to one 
of V. Rafflesiana in the stove it was immediately acted upon. Comparing the 
behaviour of fibrine, meat, and cartilage placed in tubes of MNepenthes-fluid, with 
that in tubes of distilled water, I observed that their disintegration is three times 
more rapid in the fluid; but this disintegration is wholly different from that 
which follows the immersion of these substances in the fluid of the pitcher of a 
living plant. 
In the case of small portions of meat, 3-2 grains, all seems to be absorbed ; but 
with 8-10 grains of cartilage it is not so—a certain portion disappears, the rest 
remains as a transparent poly, and finally becomes putrid, but not till after many 
days. Insects appear to be acted upon somewhat differently ; for after several days’ 
immersion of a large piece of cartilage I found that a good-sized cockroach, which 
had followed the cartilage and was drowned for his temerity, in two days became 
utrid. After removing the cockroach the cartilage remained inodorous for many 
ays. In this case no doubt the antiseptic fluid had permeated the tissue of the 
cartilage, whilst enough did not remain to penetrate the chitinous hard covering of 
the insect, which consequently decomposed. 
In the case of cartilage placed in fluid taken from the pitcher, it becomes putrid, 
but not so soon as if placed in distilled water. 
From the above observations it would appear probable that a substance acting as 
pepsine does is given off from the inner wall of the pitcher, but chiefly after placing 
animal matter in the acid fluid ; but whether this active agent flows from the glands, 
or from the cellular tissue in which they are imbedded, I have no evidence to show. 
I have here not alluded to the action of these animal matters in the cells of the 
glands, which, as has been observed by Mr. Darwin in Drosera, produces remark- 
able changes in their protoplasm, ending in their discoloration. Not only is 
there aggregation of the protoplasm in the gland-cells, but the walls of the cells 
themselves become discoloured, and the glandular surface of the pitcher that at 
first was of a uniform green, becomes covered with innumerable brown specks 
(which are the discoloured glands). After the function of the glands is exhausted, 
the fluid evaporates and the pitcher slowly withers. 
At this stage I am obliged to leave this interesting investigation. That Nepen- 
thes possesses a true digestive process, such as has been proved in the case of Drosera, 
Dionea, and Pinguicula, cannot be doubted. This process, however, takes place in 
a fluid which deprives us of the power of following it further by direct observation. 
We cannot here witness the pouring out of the digestive principle; we must, assume 
its presence and nature from the behaviour of the animal matter placed in the fluid 
in the pitcher. From certain characters of the cellular tissue of the interior walls 
of the pitcher, I am disposed to think that it takes little part in the Ercan of 
1874. 
