Chap. XIII.] EFFECTS OF VAPOUKS. 247 



again the leaf at the end enclosing the cheese opened before the 

 opposite end with the albumen; but no further observations were 

 made. 



Experiment IS. A globule of chemically prepared casein, about 

 i\f of an inch in diameter, was placed on a leaf, which spontaneous- 

 ly opened after eight days. The casein now consisted of a soft 

 sticky mass, very little, if at all, reduced in size, but bathed in 

 acid secretion. 



These experiments are sufficient to show that the secre- 

 tion from the glands of Diona3a dissolves albumen, gelatine, 

 and meat, if too large pieces are not given. Globules of fat 

 and fibro-elastic tissue are not digested. The secretion, with 

 its dissolved matter, if not in excess, is subsequently ab- 

 sorbed. On the other hand, although chemically prepared 

 casein and cheese (as in the case of Drosera) excite much 

 acid secretion, owing, I presume, to the absorption of some 

 included albuminous matter, these substances are not di- 

 gested, and are not appreciably, if at all, reduced in bulk. 



Effects of the Vapours of Chloroform, Sulphuric Ether, and 

 Uydrocyunic Acid. A plant bearing one leaf was introduced into 

 a large bottle with a drachm (3.549 c.c.) of chloroform, the mouth 

 being imperfectly closed with cotton-wool. The vaf)our caused in 

 1 m. the lobes to begin moving at an imperceptibly slow rate; but 

 in 3 m. the spikes crossed, and the leaf was soon completely shut. 

 The dose, however, was much too large, for in between 2 and 3 hrs. 

 the leaf appeared as if burnt, and soon died. 



Two leaves were exposed for 30 m. in a 2-oz. vessel to the 

 vapour of 30 minims (1.774 c.c.) of sulphuric ether. One leaf 

 closed after a time, as did the other whilst being removed from 

 the vessel without being touched. Both leaves were greatly in- 

 jured. Another leaf, exposed for 20 m. to 15 minims of ether, 

 closed its lobes to a certain extent, and the sensitive filaments 

 were now quite insensible. After 24 hrs. this leaf recovered its 

 sensibility, but was still rather torpid. A leaf exposed in a large 

 bottle for only 3. m. to ten drops was rendered insensible. After 

 52 m. it recovered its sensibility, and when one of the filaments 

 was touched, the lobes closed. It began to reopen after 20 hrs. 

 Lastly another leaf was exposed for 4 m. to only four drops of the 

 ether; it was rendered insensible, and did not close when its iila- 

 raents were repeatedly touched, but closed when the end of the 

 open leaf was cut off. This shows either that the internal parts 

 had not been rendered insensible, or that an incision is a more pow- 

 erful stimulus than repeated touches on the filaments. Whether 

 the larger doses of chloroform and ether, which caused the loaves to 

 close slowly, acted on the sensitive filaments or on the leaf itself, I 

 do not know. 



