68 DROSEKA ROTUNDIFOLIA. Chap IV. 



when tho leaves are subsequently placed in a solution of car- 

 bonate of ammonia. But the most remarkable change is that 

 the glands become opaque and uniformly white ; and this may 

 be attributed to the coagulation of their albuminous contents. 



My first and preliminary experiment consisted in putting 

 seven leaves in the same vessel of water, and warming it slowly 

 up to the temperature of 110° Fahr. (43°-3 Cent.) ; a leaf being 

 taken out as soon as the temperature rose to 80° (26°-6 Cent.), 

 another at 85°, another at 90°, and so on. Each leaf, when taken 

 out, was placed in water at the temperature of my room, and 

 "the tentacles of all soon became slightly, though iii-egularly, 

 inflected. They were now removed fi'om the cold water and 

 kept in damp air, with bits of meat placed on their discs. 

 The leaf which had been exposed to the temperature of 110° 

 became in 15 m. greatly inflected ; and in 2 hrs. every single 

 tentacle closely embraced the meat. So it was, but affer rather 

 longer intervals, with the six other leaves. It appears, there- 

 fore, that the warm bath had increased their sensitiveness 

 when excited by meat. 



I next observed the degree of inflection which leaves under- 

 went within stated periods, whilst still immersed in warm 

 water, kept as nearly as possible at the same temperature ; but 

 I will here and elsewhere give only a few of the many trials 

 made. A leaf was left for 10 m. in water at 100° (37°-7 Cent.), 

 but no inflection occurred. A second leaf, however, treated in 

 the same manner, had a few of its exterior tentacles very 

 slightly inflected in 6 m., and several irregularly but not closely 

 inflected in 10 m. A third leaf, kept in water at 105° to 106° 

 (40°.5 to 41°-1 Cent.), was very moderately inflected in 6 m. 

 A fourth leaf, in water at 110° (43°-3 Cent.), was somewhat in- 

 flected in 4 m., and considerably so in from 6 m. to 7 m. 



Three leaves were placed in water which was heated rather 

 quickly, and by the time the temperature rose to 115°— 116° 

 (46°"1 to 46°'06 Cent.), all three were inflected. I then removed 

 the lamp, and in a few minutes every single tentacle was 

 closely inflected. The protoplasm within the cells was not 

 killed, for it was seen to be in distinct movement; and the 

 leaves, having been left in cold water for 20 hrs., re-expanded. 

 Another leaf was immersed in water at 100° (37°-7 Cent.), which 

 was raised to 120° (48°-8 Cent.); and all the tentacles, except 

 tho extreme marginal ones, soon became closely inflected. 

 Tho leaf was now placed in cold water, and in 7 hrs. 30 m. it 

 had partly, and in 10 hrs. fully, re-expanded. On the follow- 

 ing morning it was immersed in a weak solution of carbonate of 



