carbonate of ammonia to 109 of water, and became finely aggregated. On
the other hand, leaves, after an immersion in water at 150 (65 .5
Cent.), on being placed in the same strong solution, did not undergo
aggregation, the cells becoming filled with brownish, pulpy, or muddy
matter. With leaves subjected to temperatures between these two
extremes of 120 and 150 Fahr. (48 .8 and 65 .5 Cent.), there were
gradations in the completeness of the process; the former temperature
not preventing aggregation from the subsequent action of carbonate of
ammonia, the latter quite stopping it. Thus, leaves immersed in water,
heated to 130 (54 .4 Cent.), and then in the solution, formed
perfectly defined spheres, but these were decidedly smaller than in
ordinary cases. With other leaves heated to 140 (60 Cent.), the
spheres were extremely small, yet well defined, but many of the cells
contained, in addition, some brownish pulpy matter. In two cases of
leaves heated to 145 (62 .7 Cent.), a few tentacles could be found
with some of their cells containing a few minute spheres; whilst the
other cells and other whole tentacles included only the brownish,
disintegrated or pulpy matter.
The fluid within the cells of the tentacles must be in an oxygenated
condition, in order that the force or [page 59] influence which induces
aggregation should be transmitted at the proper rate from cell to cell.
A plant, with its roots in water, was left for 45 m. in a vessel
containing 122 oz. of carbonic acid. A leaf from this plant, and, for
comparison, one from a fresh plant, were both immersed for 1 hr. in a
rather strong solution of carbonate of ammonia. They were then
compared, and certainly there was much less aggregation in the leaf
which had been subjected to the carbonic acid than in the other.
Another plant was exposed in the same vessel for 2 hrs. to carbonic
acid, and one of its leaves was then placed in a solution of one part
of the carbonate to 437 of water; the glands were instantly blackened,
showing that they had absorbed, and that their contents were
aggregated; but in the cells close beneath the glands there was no
aggregation even after an interval of 3 hrs. After 4 hrs. 15 m. a few
minute spheres of protoplasm were formed in these cells, but even after
5 hrs. 30 m. the aggregation did not extend down the pedicels for a
length equal to that of the glands. After numberless trials with fresh
leaves immersed in a solution of this strength, I have never seen the
aggregating action transmitted at nearly so slow a rate. Another plant
was left for 2 hrs. in carbonic acid, but was then exposed for 20 m. to
52