ClIAl". XIII. 



DIGESTION. 



301 



mens kept in water. I then tried suspending a leaf 

 in a bottle over an excessively putrid infusion of 

 raw meat, to see whether they absorbed the vapour, 

 but their contents were not affected. 



Digestive Power of the Secretion* When a leaf closes 

 over any object, it may be said to form itself into a 

 temporary stomach ; and if the object yields ever so 

 little animal matter, this serves, to use Schiffs expres- 

 sion, as a peptogene, and the glands on the surface 

 pour forth their acid secretion, which acts like the 

 gastric juice of animals. As so many experiments 

 were tried on the digestive power of Drosera, only a 

 few were made with Dionaja, 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 - OS mm.) long, and 



* Dr. W. M. Canby, of Wil- 

 mington, to whom I am much 

 indebted for information regard- 

 ing Dionfea in its lative home, 

 has published in the ' Gardener's 

 Monthly,' Philadelphia, August 

 1868, some interesting observa- 

 tions. He ascertained that the 

 secretion digests animal matter, 

 such as the contents of insects, 

 bits of meat, &c. ; and that the 

 secretion is reabsorbed. He was 

 also well aware that the lobes 

 remain closed for a much longer 

 time when in contact with animal 

 matter than when made to shut 

 by a mere touch, or over objects 



not yielding soluble nutriment; 

 and that in these latter cases the 

 glands do not secrete. The Rev. 

 Dr. Curtis first observed (' Boston 

 Journal Nat. Hist.' vol. i. p. 123) 

 the secretion from the glands. I 

 may here add that a gardener. 

 Mr. Knight, is said (Kirby and 

 Spencer's ' Introduction to Ento- 

 mology,' 1818, vol. i. p. 295) to 

 have found that a plant of the 

 Dion?ea, on the leaves of which 

 "he laid fine filaments of raw 

 beef, was much more luxuriant 

 in its growth than others not so 

 treated." 



