a reversed direction to that of aggregation. Tentacles in an aggregated
condition were shown to Prof. Huxley, Dr. Hooker, and Dr. Burdon
Sanderson, who observed the changes under the microscope, and were much
struck with the whole phenomenon. [page 40]
The little masses of aggregated matter are of the most diversified
shapes, often spherical or oval, sometimes much elongated, or quite
irregular with thread- or necklace-like or club-formed projections.
They consist of thick, apparently viscid matter, which in the exterior
tentacles is of a purplish, and in the short distal tentacles of a
greenish, colour. These little masses incessantly change their forms
and positions, being never at rest. A single mass will often separate
into two, which afterwards reunite. Their movements are rather slow,
and resemble those of Amoebae or of the white corpuscles of the blood.
We
FIG. 7. (Drosera rotundifolia.) Diagram of the same cell of a tentacle,
showing the various forms successively assumed by the aggregated masses
of protoplasm.
may, therefore, conclude that they consist of protoplasm. If their
shapes are sketched at intervals of a few minutes, they are invariably
seen to have undergone great changes of form; and the same cell has
been observed for several hours. Eight rude, though accurate sketches
of the same cell, made at intervals of between 2 m. or 3 m., are here
given (fig. 7), and illustrate some of the simpler and commonest
changes. The cell A, when first sketched, included two oval masses of
purple protoplasm touching each other. These became separate, as shown
at B, and then reunited, as at C. After the next interval a very common
appearance was presented [page 41] D, namely, the formation of an
extremely minute sphere at one end of an elongated mass. This rapidly
increased in size, as shown in E, and was then re-absorbed, as at F, by
which time another sphere had been formed at the opposite end.
The cell above figured was from a tentacle of a dark red leaf, which
had caught a small moth, and was examined under water. As I at first
thought that the movements of the masses might be due to the absorption
of water, I placed a fly on a leaf, and when after 18 hrs. all the
tentacles were well inflected, these were examined without being
immersed in water. The cell
35