After 24 hrs. the damp meat had excited some acid secretion, and the lobes at this end of the leaf were almost shut.  At the other end, where the damp gelatine lay, the leaf was still quite open, nor had any secretion been excited; so that, as with Drosera, gelatine is not nearly so exciting a substance as meat.  The secretion beneath the meat was tested by pushing a strip of litmus paper under it (the filaments not being touched), and this slight stimulus caused the leaf to shut.  On the eleventh day it reopened; but the end where the gelatine lay, expanded several hours before the opposite end with the meat.

A second bit of roast meat, which appeared dry, though it had not been purposely dried, was left for 24 hrs. on a leaf, caused neither movement nor secretion.  The plant in its pot was now covered with a bell-glass, and the meat absorbed some moisture from the air; this sufficed to excite acid secretion, and by the next morning the leaf was closely shut.  A third bit of meat, dried so as to be quite brittle, was placed on a leaf under a bell-glass, and this also became in 24 hrs. slightly damp, and excited some acid secretion, but no movement.

A rather large piece of perfectly dry albumen was left at one end of a leaf for 24 hrs. without any effect.  It was then soaked for a few minutes in water, rolled about on blotting paper, and replaced on the leaf; in 9 hrs. some slightly acid secretion was excited, and in 24 hrs. this end of the leaf was partially closed.  The bit of albumen, which was now surrounded by much secretion, was gently removed, and although no filament was touched, the lobes closed.  In this and the previous case, it appears that the absorption of animal matter by the glands renders [page 298] the surface of the leaf much more sensitive to a touch than it is in its ordinary state; and this is a curious fact.  Two days afterwards the end of the leaf where nothing had been placed began to open, and on the third day was much more open than the opposite end where the albumen had lain.

Lastly, large drops of a solution of one part of carbonate of ammonia to 146 of water were placed on some leaves, but no immediate movement ensued.  I did not then know of the slow movement caused by animal matter, otherwise I should have observed the leaves for a longer time, and they would probably have been found closed, though the solution (judging from Drosera) was, perhaps, too strong.

From the foregoing cases it is certain that bits of meat and albumen, if at all damp, excite not only the glands to secrete, but the lobes to close.  This movement is widely different from the rapid closure caused by one of the filaments being touched.  We shall see its importance when we treat of the manner in which insects are captured.  There is a great contrast between Drosera and Dionaea in the effects produced by mechanical irritation on the one hand, and the absorption of animal matter on the other.  Particles of glass placed on the glands of the exterior