1 m. in water at 120 (48 .8 Cent.) and then left for 1 hr. 26 m. in
cold water; the tentacles were but little inflected, and there was only
here and there a trace of aggregation. In all these and other trials
with warm water the protoplasm showed much less tendency to aggregate
into spherical masses than when excited by carbonate of ammonia.
Redissolution of the Aggregated Masses of Protoplasm. As soon as
tentacles which have clasped an insect or any inorganic object, or have
been in any way excited, have fully re-expanded, the aggregated masses
of protoplasm are redissolved and disappear; the cells being now
refilled with homogeneous purple fluid as they were before the
tentacles were inflected. The process of redissolution in all cases
commences at the bases of the tentacles, and proceeds up them towards
the glands. In old leaves, however, especially in those which have been
several times in action, the protoplasm in the uppermost cells of the
pedicels remains in a permanently more or less aggregated condition. In
order to observe the process of redissolution, the following
observations were made: a leaf was left for 24 hrs. in a little
solution of one part of carbonate of ammonia to 218 of water, and the
protoplasm was as usual aggregated into numberless purple spheres,
which were incessantly changing their forms. The leaf was then washed
and placed in distilled water, and after 3 hrs. 15 m. some few of the
spheres began to show by their less clearly defined edges signs of
redissolution. After 9 hrs. many of them had become elongated, and the
surrounding fluid in the cells was slightly more coloured, showing
plainly that redissolution had commenced. After 24 hrs., though many
cells still contained spheres, here and there one [page 54] could be
seen filled with purple fluid, without a vestige of aggregated
protoplasm; the whole having been redissolved. A leaf with aggregated
masses, caused by its having been waved for 2 m. in water at the
temperature of 125 Fahr., was left in cold water, and after 11 hrs.
the protoplasm showed traces of incipient redissolution. When again
examined three days after its immersion in the warm water, there was a
conspicuous difference, though the protoplasm was still somewhat
aggregated. Another leaf, with the contents of all the cells strongly
aggregated from the action of a weak solution of phosphate of ammonia,
was left for between three and four days in a mixture (known to be
innocuous) of one drachm of alcohol to eight drachms of water, and when
re-examined every trace of aggregation had disappeared, the cells being
now filled with homogeneous fluid.
48