weit. | 
Cuar. VIL] PHOSPHATE OF AMMONIA. 131 
or *0000387 mg. Lastly, leaf No. 11, which had after 24 hrs. all its 
tentacles, except one, closely inflected, as well as the blade, bore the 
unusually large number of 252 tentacles; and, on the same principle 
as before, each gland could have absorbed only the s55}o55 of a grain, 
or °0000322 mg. 
With respect to the following experiments, I must premise that the 
leaves, both those placed in the solutions and in water, were taken 
from plants which had been kept in a very warm greenhouse during 
the winter. ‘They were thus rendered extremely. sensitive, as was 
shown by water exciting them much more than in the previous 
experiments. Before giving my observations, it may be well to remind 
the reader that, judging from thirty-one fine leaves, the average 
number of tentacles is 192, and that the outer or exterior ones, the 
movements of which are alone significant, are to the short ones on the 
disc in the proportion of about sixteen to nine. 
Four leaves were immersed as before, each in thirty minims of a 
solution of one part to 328,125 of water (1 gr. to 750 oz.). Each leaf 
thus received z5455 Of a grain (*0054 mg.) of the salt; and all four 
were greatly intlected. 
(1) After 1 hr. all the outer tentacles but one inflected, and the 
blade greatly so; after 7 hrs. began to re-expand, 
(2) After 1 hr. all the outer tentacles but eight inflected; after 12 
hrs. all re-expanded. 
(3) After 1 hr. much inflection; after 2 hrs. 30 m. all the tentacles 
but thirty-six inflected; after 6 hrs. all but twenty-two inflected ; 
after 12 hrs. partly re-expanded. 
(4) After 1 hr. all the tentacles but thirty-two inflected; after 2 
hrs. 30 m. all but twenty-one inflected; after 6 hrs. almost re- 
expanded. 
Of the four corresponding leaves in water :— 
(1) After 1 hr. forty-five tentacles inflected; but after 7 lirs, so 
many had re-expanded that only ten remained much inflected. 
(2) After 1 hr. seven tentacles inflected; these were almost re- 
expanded in 6 hrs. 
(3) and (4) Not affected, except that, as usual, after 11 hrs. the 
short tentacles on the borders of the dise formed a ring. 
There can, therefore, be no doubt about the efficiency of the above 
solution; and it follows as before that each gland of No. 1 could have 
absorbed only 3574559 Of a grain (*0000268 mg.) and of No. 2 only 
szadoos Of a grain (0000263 mg.) of the phosphate. 
Seven leaves were immersed, each in thirty minims of a solution of 
one part to 437,500 of water (1 gr. to 1000 oz.). Each leaf thus 
received +;355 of a grain (-00405 mg.). The day was warm, and the 
leaves were very fine, so that all circumstances were favourable. 
(1) After 30 m. all the outer tentacles except five inflected, and 
K 2 
