vii. ruosriiATE OF AMMONIA. 165 



and most of them rather closely, four or five being only sub- 

 inflected. 



(3) No change for the first 12 hrs.; but after 24 hrs. all the 

 tentacles excepting those of the outermost row were sub-inflected, 

 with the blade inflected. After 3u hrs. blade strongly inflected, 

 with all the tentacles, except three, inflected or sub -inflected. 

 After 48 hrs. in the same state. 



(4) to (8) These leaves, after 2 hrs. 30 m., had respectively 

 32, 17, 7, 4, and tentacles inflected, most of which, after a few 

 hours, re-expanded, with the exception of No. 4, which retained 

 its thirty-two tentacles inflected for 48 hrs. 



Now for the eight corresponding leaves in water : 



(1) After 2 hrs. 40 m. this had twenty of its outer tentacles 

 inflected, five of which re-expanded after 6 hrs. 30 m. After 

 10 hrs. 15 m. a most unusual circumstance occurred, namely, 

 the whole blade became slightly bowed towards the footstalk, 

 and so remained for 48 hrs. The exterior tentacles, excepting 

 those of the three or four outermost rows, were now also in- 

 flected to an unusual degree. 



(2) to (8) These leaves, after 2 hrs. 40 m., had respectively 42, 

 12, 9, 8, 2, 1, and tentacles inflected, which all re-expanded 

 within 24 hrs., and most of them within a much shorter time. 



When the two lots of eight leaves in the solution and in the 

 water were compared after the lapse of 24 hrs., they undoubt- 

 edly differed much in appearance. The few tentacles on the 

 leaves in water which were inflected had after this interval re- 

 expanded, with the exception of one leaf; and this presented 

 the very unusual case of the blade being somewhat inflected, 

 though in a degree hardly approaching that of the two leaves in 

 the solution. Of these latter leaves, No. 1 had almost all its 

 tentacles, together with its blade, inflected after an immersion 

 of 2 hrs. 30 in. Leaves No. 2 and 3 were affected at a much 

 slower rate; but after from 24 hrs. to 48 hrs. almost all their 

 tentacles were closely inflected, and the blade of one quite 

 doubled up. We must therefore admit, incredible as the fact 

 may at first appear, that this extremely weak solution acted on 

 the more sensitive leaves ; each of which received only the 

 80000 of a grain ('00081 nig.) of the phosphate. Now, leaf 

 No. 3 bore 178 tentacles, and subtracting the three which were 

 not inflected, each gland could have absorbed only the 1 4060000 

 of a grain, or '00000463 mg. Leaf No. 1, which was strongly 

 acted on within 2 hrs. 30 m., and had all its oiiter tentacles, 

 except thirteen, inflected within 6 hrs. 30 m., bore 260 tentacles; 

 and on the same principle as before, each gland could hstva 



