58 DROSERA ROTUNDIFOLIA. [Cuar. IV. 
nearly as possible at the same temperature; but I will here and else- 
where give only a few of the many trials made. A leaf was left for 
10 m. in water at 100° (37°°7 Cent.), but no inflection occurred. A 
second leaf, however, treated in the same manner, had a few of its 
exterior tentacles very slightly inflected in 6 m., and several irregularly 
but not closely inflected in 10m. A third leaf, kept in water at 105° 
to 106° (40°°5 to 40°-1 Cent.), was very moderately inflected in 6 m. 
A fourth leaf, in water at 110° (43°°3 Cent.), was somewhat inflected 
in 4 m., and considerably so in from 6 m. to 7 m. 
Three leaves were placed in water which was heated rather quickly, 
and by the time the temperature rose to 115°—-116° (46°°1 to 46°-06 
Cent.), all three were inflected. I then removed the lamp, and in a 
few minutes every. single tentacle was closely inflected. ‘lhe proto- 
plasm within the cells was not killed, for it was seen to be in distinct 
movement; and the leaves, having been left in cold water for 20 hrs., 
re-expanded. Another leaf was immersed in water at 100° (87°°7 
Cent.), which was raised to 120° (48°°8 Cent.) ; and all the tentacles, 
except the extreme marginal ones, soon became closely inflected. ‘The 
leaf was now placed in cold water, and in 7 hrs. 30 m. it had partly, 
and in 10 hrs. fully, re-expanded. On the following morning it was 
immersed in a weak solution of carbonate of ammonia, and the glands 
quickly became black, with strongly marked aggregation in the 
tentacles, showing that the protoplasm was alive, and that the glands 
had not lost their power of absorption. Another leaf was placed in 
water at 110° (43°°3 Cent.) which was raised to 120° (48°°8 Cent.); 
and every tentacle, excepting one, was quickly and closely inflected. 
This leaf was now immersed in a few drops of a strong solution of car- 
bonate of ammonia (one part to 109 of water) ; in 10 m. all the glands 
became intensely black, and in 2 hrs. the protoplasm in the cells of 
the pedicels was well aggregated. Another leaf was suddenly plunged, 
and as usual waved about, in water at 120°, and the tentacles became 
inflected in from 2 m. to 3 m., but only so as to stand at right angles 
to the disc. The leaf was now placed in the same solution (viz. 
one part of carbonate of ammonia to 109 of water, or 4 grs. to 1 0z., 
which I will for the future designate as the strong solution), and when 
I looked at it again after the interval of an hour, the glands were 
blackened, and there was well-marked aggregation. After an additional 
interval of 4 hrs. the tentacles had become much more inflected. It 
deserves notice that a solution as strong as this never causes infection 
in ordinary cases. Lastly, a leaf was suddenly placed in water at 125° 
(51°°6 Cent.), and was left in it until the water cooled; the tentacles 
were rendered of a bright red and soon became inflected. 'The contents 
of the cells underwent some degree of aggregation, which in the course 
of three hours increased ; but the masses of protoplasm did not become 
spherical, as almost always occurs with leaves immersed in a solution 
of carbonate of ammonia. 
We learn from these cases that a temperature of from 120° 
