156 DROSERA ROTUNDIFOLIA. Cuap. VIL. 
eaten this latter case each gland could have received only the 
<resoo (or 000563 mg.) of a grain. Lastly, similar drops of a 
solution of one part to 1750 of water (1 gr. to 402.) were tried on 
five leaves; a drop being applied to four glands on the same 
leaf. The tentacles on three of these leaves were not in the 
least affected ; on the fourth leaf, two became inflected; whilst 
on the fifth, which happened to be a very sensitive one, all four 
tentacles were plainly inflected in 6 hrs. 15 m.; but only one re- 
mained inflected after 24 hrs, I should, however, state that in 
this case an unusually large drop adhered to the head of the 
pin. rahe of these glands could have received very little more 
than ,sesa0 Of a grain (or 000423); but this small quantity 
sufficed to cause inflection. We must bear in mind that these 
drops were applied to the viscid secretion for only from 10 to 
15 seconds, and we have good reason to believe that all the 
phosphate in the solution would not be diffused and absorbed in 
this time. We have seen wee the same circumstances that the 
Bede nan by a gland of syioo Of a grain of the carbonate, and 
of 57495 Of a grain of the nitrate, did not cause the tentacle bear- 
ing the gland in question to be inflected; so that here again the 
phosphate is much more powerful than the other two salts, 
We will now turn to the 106 experiments with immersed 
leaves. Having ascertained by repeated trials that moderately 
strong solutions were highly efficient, I commenced with sixteen 
leaves, each placed in thirty minims of a solution of one part 
to 43,750 of water (1 gr. to 100 oz.); so that each received 
sdoo Of a grain, or 04058 mg. Of these leaves, eleven had 
nearly all or a great number of their tentacles inflected in 
1 hr., and the twelfth leaf in 3 hrs. One of the eleven had 
every single tentacle closely inflected in 50 m. Two leaves out 
of the sixteen were only moderately affected, yet more so 
than any of those simultaneously immersed in water; and the 
remaining two, which were pale leaves, were hardly at all 
affected. Of the sixteen corresponding leaves in water, one 
had nine tentacles, another six, and two others two tentacles 
inflected, in the course of 5 hrs. So that the contrast ‘ir 
appearance between the two lots was extremely great. 
Eighteen leaves were immersed, each in thirty minims of a 
solution of one part to 87,500 of water (1 gr. to 200 oz.), so 
that each received 5545 of a grain (0202 mg.). Fourteen ot 
these were strongly inflected within 2 hrs, and some of them 
within 15 m.; three out of the eighteen were only slightly 
affected, having twenty-one, nineteen, and twelve tentacles in- 
