Chap. XIIL] DIGESTION. 245 



matter, this serves, to use SchifFs expression, as a pepto- 

 gene," and the glands on the surface pour forth their acid 

 secretion, which acts like the gastric juice of animals. As 

 80 many experiments were tried on the digestive power of 

 Drosera, only a few were made with Dionsea, but they were 

 amply sufficient to prove that it digests. This plant, more- 

 over, is not so well fitted as Drosera for observation, as the 

 process goes on within the closed lobes. Insects, even beetles, 

 after being subjected to the secretion for several days, are 

 surprisingly softened, though their chitinous coats are not 

 corroded. 



Experiment 1. A cube of albumen of -^ of an inch (2.540 mm.) 

 was placed at one end of a leaf, and at the other end an oblong 

 piece of gelatine, ^ of an inch (5.08 ram.) long, and ^^ broad; the 

 leaf was then made to close. It was cut open after 45 hrs. The 

 albumen was hard and compressed, with its angles only a little 

 rounded; the gelatine was corroded into an oval form; and both 

 were bathed in so much acid secretion that it dropped off the leaf. 

 The digestive process apparently is rather slower than in Drosera, 

 and this agrees with the length of time during which the leaves 

 remain closed over digestible objects. 



Experiment 2. A bit of albumen -^ of an inch square, but only 

 ^ in thickness, and a piece of gelatine of the same size as before, 

 were placed on a leaf, which eight days afterwards was cut open. 

 The surface was bathed with slightly adhesive, very acid secretion, 

 and the glands were all in an aggregated condition. Not a vestige 

 of the albumen or gelatine was left. Similarly sized pieces were 

 placed at the same time on wet moss on the same pot, so that they 

 were subjected to nearly similar conditions; after eight days these 

 were brown, decayed, and matted with fibres of mould, biit had 

 not disappeared. 



Experiment S. A piece of albumen ^ of an inch (3.81 mm.) 

 long, and t^ broad and thick, and a piece of gelatine of the same 

 size as before, were placed on another leaf, which was cut open 

 after seven days; not a vestige of either substance was left, and 

 only a moderate amount of secretion on the surface. 



Experiment 4. Pieces of albumen and gelatine, of the same 

 size as in the last experiment, were placed on a leaf, which spon- 

 taneously opened after twelve days, and here again not a vestige 

 of either was left, and only a little secretion at one end of the 

 midrib. 



Experiment 5. Pieces of albumen and gelatine of the same size 

 were placed on another leaf, which after twelve days was still 

 firmly closed, but had begun to wither; it was cut open, and con- 

 tained nothing except a vestige of brown matter where the albu- 

 men had lain. 



" [flee footnote, p. 10G.-F. D.] 



