66 DROSERA ROTUNDIFOLIA. [Cuar. V. 
Olive Oil—Drops were placed on the discs of eleven leaves, and no 
effect was produced in from 24 hrs. to 48 hrs. Four of these leaves 
were then tested by bits of meat on their discs, and three of them were 
found after 24 hrs. with all their tentacles and blades closely inflected, 
whilst the fourth had only a few tentacles inflected. It will, however, 
be shown in a future place, that cut-off leaves immersed in olive oil 
are powerfully affected. 
Infusion and Decoction of Tea.—Drops of a strong infusion and 
decoction, as well as of a rather weak decoction, of tea were placed on 
ten leaves, none of which became inflected. I afterwards tested three 
of them by adding bits of meat to the drops which still remained on 
their discs, and when I examined them after 24 hrs. they were closely 
inflected. The chemical principle of tea, namely theine, was 
subsequently tried and produced no effect. The albuminous matter 
which the leaves must originally have contained, no doubt, had been 
rendered insoluble by their having been completely dried. 
We thus see that, excluding the experiments with water, 
sixty-one leaves were tried with drops of the 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 effect, I neglected in most 
cases to record how soon the 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 
occasion 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 tentacles 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 
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