180 DROSERA ROTUNDIFOLIA. (CHAP. IX. 
with and without meat, were closely inflected; so that the ether 
apparently had stimulated these leaves, causing all the tentacles to 
bend. 
Vapour of Nitric Ether.—This vapour seems more injurious than 
that of sulphuric ether. A plant was exposed for 5 m.in a 12-07. 
vessel to eight drops in a watch-glass, and I distinctly saw a few 
tentacles curling inwards before the glass was removed, Immediately 
afterwards bits of meat were placed on three glands, but no movement 
ensued in the course of 18 m. ‘The same plant was placed again under 
the same vessel for 16 m. with ten drops of the ether. None of the 
tentacles moved, and next morning those with the meat were still in 
the same position. After 48 brs. one leaf seemed healthy, but the 
others were much injured. 
Another plant, having two good leaves, was exposed for 6 m. under 
a 19-oz. vessel to the vapour from ten minims of the ether, and bits of 
meat were then placed on the glands of many tentacles on both leaves. 
After 36 m. several of them on one leaf became inflected, and after 
1 hr.almost all the tentacles, those with and without meat, nearly reached 
the centre. On the other leaf the glands began to dry in 1 hr. 40 m., 
and after several hours not a single tentacle was inflected ; but by the 
next morning, after 21 hrs., many were inflected, though they seemed 
rnuch injured. In this and the previous experiment, it is doubtful, 
owing to the injury which the leaves had suffered, whether any 
anesthetic effect had been produced. 
A third plant, having two good leaves, was exposed for only 4 m. 
in the 19-0z. vessel to the vapour from six drops. Bits of meat were 
then placed on the glands of seven tentacles on the same leaf. A 
single tentacle moved after 1 hr. 23 m.; after 2 hrs. 3 m. several were 
inflected; and after 3 hrs. 3 m. all the seven tentacles with meat were 
well inflected. From the slowness of these movements it is clear that 
this leaf had been rendered insensible for a time to the action of the 
meat. A second leaf was rather differently affected; bits of meat 
were placed on the glands of five tentacles, three of which were 
slightly inflected in 28 m.; after 1 hr. 21 m. one reached the centre, 
but the other two were still only slightly inflected; after 3 hrs. they 
were much more inflected; but even after 5 hrs. 16 m. all five had 
not reached the centre. Although some of the tentacles began to 
move moderately soon, they afterwards moved with extreme slowness. 
By next morning, after 20 hrs., most of the tentacles on both leaves 
were closely inflected, but not quite regularly. After 48 hrs. neither 
leaf appeared injured, though the tentacles were still inflected; after 
72 hrs. one was almost dead, whilst the other was re-expanding and 
recovering. 
Carbonic Acid.—A plant was placed under a 122-oz. bell-glass 
filled with this gas and standing over water; but I did not make 
sufficient allowance for the absorption of the gas by the water, so that 
towards the latter part of the experiment some air was drawn in. 
After an exposure of 2 hrs. the plant was removed, and bits of raw 
