160 DEOSERA ROTUNDIFOLIA. CHAP. VII. 



iO m. all the outer tentacles except twenty-five were inflected, 

 as was the blade in a strongly marked manner. After 24 hrs. 

 every tentacle except one was closely inflected, and the blade 

 was completely doubled over. Thus the leaf remained for two 

 days, when it began to re-expand. 1 may. add that the three 

 latter leaves (Nos. 9, 10, and 11) were still somewhat inflected 

 after three days. The tentacles in but few of these eleven leaves 

 became closely inflected within so short a time as in the pre- 

 vious experiments with stronger solutions. 



We will now turn to the twenty corresponding leaves in water. 

 Nine had none of their outer tentacles inflected ; nine others 

 had from one to three inflected ; and these re-expanded after 

 8 hrs. The remaining two leaves were moderately affected ; one 

 having six tentacles inflected in 34 m. ; the other twenty-three 

 inflected in 2 hrs. 12 m. ; and both thus remained for 24 hrs. 

 None of these leaves had their blades inflected. So that the con- 

 trast between the twenty leaves in water and the twenty in the 

 solution was very great, both within the first hour and after 

 from 8 to 12 hrs. had elapsed. 



Of the leaves in the solution, the glands on leaf No. 1, which 

 in 2 hrs. had all its tentficles except eight inflected, were 

 counted and found to be 202. Subtracting the eight, each gland 

 could have received only the -j-g siwo f a grain ("0000411 mg.) 

 of the phosphate. Leaf No. 9 had 213 tentacles, all of which, 

 with the exception of four, were inflected after 24 hrs., but 

 none of them closely ; the blade was also inflected ; each gland 

 could have received only the Ifi7 ^ 000 of a grain, or '0000387 

 mg. Lastly, leaf No. 11, which had after 24 hrs. all its ten- 

 tacles, 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 

 oo 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 ex- 

 tremely 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 

 J92, and that the outer or exterior ones, the movements of 

 which are alone significant, are to the short ones on the disc in 

 luc proportion of about sixteen to nine. 



