stream of protoplasm on the walls of the cells ceases to be visible; I
observed this fact repeatedly, but will give only one instance. A pale
purple leaf was placed in a few drops of a solution of one part to 292
of water, and in 2 hrs. some fine purple spheres were formed in the
upper cells of the pedicels, the stream of protoplasm round their walls
being still quite distinct; but after an additional 4 hrs., during
which time many more spheres were formed, the stream was no longer
distinguishable on the most careful examination; and this no doubt was
due to the contained granules having become united with the spheres, so
that nothing was left by which the movement of the limpid protoplasm
could be perceived. But minute free spheres still travelled up and down
the cells, showing that there was still a current. So it was next
morning, after 22 hrs., by which time some new minute spheres had been
formed; these oscillated from side to side and changed their positions,
proving that the current had not ceased, though no stream of protoplasm
was visible. On another occasion, however, a stream was seen flowing
round the cell-walls of a vigorous, dark-coloured leaf, after it had
been left for 24 hrs. in a rather stronger solution, namely, of one
part of the carbonate to 218 of water. This leaf, therefore, was not
much or at all injured by an immersion for this length of time in the
above solution of two grains to the ounce; and on being afterwards left
for 24 hrs. in water, the aggregated masses in many of the cells were
re-dissolved, in the same manner as occurs with leaves in a state of
nature when they re-expand after having caught insects.
In a leaf which had been left for 22 hrs. in a solution of one part of
the carbonate to 292 of water, some spheres of protoplasm (formed by
the self-division of a bag-like mass) were gently pressed beneath a
covering glass, and then examined under a high power. They were now
distinctly divided by well-defined radiating fissures, or were broken
up into separate fragments with sharp edges; and they were solid to the
centre. In the larger broken spheres the central part was more opaque,
darker-coloured, and less brittle than the exterior; the latter alone
being in some cases penetrated by the fissures. In many of the spheres
the line of separation between the outer and inner parts was tolerably
well defined. The outer parts were of exactly the same very pale purple
tint, as that of the last formed smaller spheres; and these latter did
not include any darker central core.