in the third and seventh chapters that immersion in distilled water
causes after a time some degree of aggregation of the protoplasm, and a
moderate amount of inflection, especially in the case of plants which
have been kept at a rather high temperature. Water does not excite a
copious secretion of mucus. We have here to consider the effects of
immersion in various fluids on the subsequent action of salts of
ammonia and other stimulants. Four leaves which had been left for 24
hrs. in water were given bits of meat, but did not clasp them. Ten
leaves, after a similar immersion, were left for 24 hrs. in a powerful
solution (1 gr. to 20 oz.) of phosphate of ammonia, and only one showed
even a trace of inflection. Three of these leaves, on being left for an
additional day in the solution, still remained quite unaffected. When,
however, some of these leaves, which had been first immersed in water
for 24 hrs., and then in the phosphate for 24 hrs. were placed in a
solution of carbonate of ammonia (one part to 218 of water), the
protoplasm in the cells of the tentacles became in a few hours strongly
aggregated, showing that this salt had been absorbed and taken effect.
A short immersion in water for 20 m. did not retard the subsequent
action of the phosphate, or of splinters of glass placed on the glands;
but in two instances an immersion for 50 m. prevented any effect from a
solution of camphor. Several leaves which had been left for 20 m. in a
solution of one part of white sugar to 218 of water were placed in the
phosphate solution, the action of which was delayed; whereas a mixed
solution of sugar and the phosphate did not in the least interfere with
the effects of the latter. Three leaves, after being immersed for 20 m.
in the sugar solution, were placed in a solution of carbonate of
ammonia (one part to 218 of water); in 2 m. or 3 m. the glands were
blackened, and after 7 m. the tentacles were considerably inflected, so
that the solution of sugar, though it delayed the action of the
phosphate, did not delay that of the carbonate. Immersion in a similar
solution of gum arabic for 20 m. had no retarding action on the
phosphate. Three leaves were left for 20 m. in a mixture of one part of
alcohol to seven parts of water, [page 214] and then placed in the
phosphate solution: in 2 hrs. 15 m. there was a trace of inflection in
one leaf, and in 5 hrs. 30 m. a second was slightly affected; the
inflection subsequently increased, though slowly. Hence diluted
alcohol, which, as we shall see, is hardly at all poisonous, plainly
retards the subsequent action of the phosphate.
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