22 DEOSEEA EOTUNDIFOLIA. CHAP. IL 



outer tentacles to bend inwards. But this follows 

 much more surely and quickly, if the object contains 

 nitrogenous matter which can be dissolved by the 

 secretion. On one occasion I observed the follow- 

 ing unusual circumstance. Small bits of raw meat 

 (which acts more energetically than any other sub- 

 stance), of paper, dried moss, and of the quill of a 

 pen were placed on several leaves, and they were all 

 embraced equally well in about 2 hrs. On other 

 occasions the above-named substances, or more com- 

 monly particles of glass, coal-cinder (taken from the 

 fire), stone, gold-leaf, dried grass, cork, blotting-paper, 

 cotton- wool, and hair rolled up into little balls, were 

 used, and these substances, though they were some- 

 times well embraced, often caused no movement what- 

 ever in the outer tentacles, or an extremely slight and 

 slow movement. Yet these same leaves were proved to 

 be in an active condition, as they were excited to move 

 by substances yielding soluble nitrogenous matter, 

 such as bits of raw or roast meat, the yolk or white of 

 boiled eggs, fragments of insects of all orders, spiders, 

 &c. I will give only two instances. Minute flies were 

 placed on the discs of several leaves, and on others 

 balls of paper, bits of moss and quill of about the same 

 size as the flies, and the latter were well embraced 

 in a few hours ; whereas after 25 hrs. only a very 

 few tentacles were inflected over the other objects. 

 The bits of paper, moss, and quill were then removed 

 from these leaves, and bits of raw meat placed on them ; 

 and now all the tentacles were soon energetically 

 inflected. 



Again, particles of coal-cinder (weighing rather more 

 than the flies used in the last experiment) were placed 

 on the centres of three leaves : after an interval of 

 19 hrs. one of the particles was tolerably well embraced ; 



