Chap. V. EFFECTS OF OEGANIC FLUIDS. 79 



above-named non-nitrogenous fluids ; and the tentacles 

 were not in a single case inflected. 



With respect to nitrogenous fluids, the first which came to 

 hand were tried. The experiments were made at the same 

 time and in exactly the same manner as the foregoing. 

 As it was immediately evident that these fluids produced a 

 great efiect, I neglected in most cases to record how soon tho 

 tentacles became inflected. But this always occurred in less 

 than 24 hrs. ; whilst the drops of non-nitrogenous fluids which 

 produced no effect were observed in every case during a 

 considerably longer period. 



Milk. — Drops were placed on sixteen leaves, and the tentacles 

 of all, as well as the blades of several, soon became greatly 

 inflected. The periods were recorded in only three cases, 

 namely, with leaves on which unusually small drops had been 

 placed. Their tentacles were somewhat inflected in 45 m. ; 

 and after 7 hrs. 45 m. the blades of two were so much curved 

 inwards that they formed little cups enclosing the drops. 

 These leaves re-expanded on the third day. On another occa- 

 sion the blade of a leaf was much inflected in 5 hrs. after a 

 drop of milk had been placed on it. 



Human Urine. — Drops were placed on twelve leaves, and the 

 tentacles of all, with a single exception, became greatly inflected. 

 Owing, I presume, to differences in the chemical nature of the 

 urine on different occasions, the time required for the movements 

 of the tentacles varied much, but was always effected in under 

 24 hrs. In two instances I recorded that all the exterior ten- 

 tacles were completely inflected in 17 hrs., but not the blade of 

 the leaf. In another case the edges of a leaf, after 25 hrs. 

 30 m., became so strongly inflected that it was converted into a 

 cup. The power of urine does not lie in the urea, which, as 

 we shall hereafter see, is inoperative. 



Albumen (fresh from a hen's egg), placed on seven leaves, 

 caused the tentacles of six of them to be well inflected. In one 

 case the edge of the leaf itself became much curled in after 

 20 hrs. The one leaf which was unaffected remained so for 

 26 hrs., and was then treated with a drop of milk, and this 

 caused the tentacles to bend inwards in 12 hrs. 



Cold Filtered Infusion of Raw Meat. — This was tried only on a 

 single leaf, which had most of its outer tentacles and the blade 

 inflected in 19 hrs. During subsequent years, I repeatedly 

 used this infusion to test leaves which had been experimented 



