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―D, namely, the formation of an
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Fig. 8.
(Drosera rotundifolia.)
Diagram of the same cell of a tentacle, showing the various forms successively assumed by the aggregated masses of protoplasm.
extremely minute sphere at one end of an elongated mass. This rapidly increased in size, as shown in E, and was then reabsorbed, as at F, by which time another sphere had been formed at the opposite end.
The cell drawn in Fig. 7 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 here represented (Fig. 8) was from this leaf, being sketched eight times in the course of 15 m. These sketches exhibit some of the more remarkable changes which the protoplasm undergoes. At first, there was at the base of the cell 1 a little mass on a short footstalk, and a larger mass near the upper end, and these seemed quite separate. Never-
which lines the walls. In the process of aggregation the vacuole expels a great part of its watery contents, retaining, however, the red colouring matter of the cell-sap, as well as tannin and albuminous matter. The vacuole does not remain a single body, but divides into numerous secondary vacuoles. The are the aggregated masses which are rendered conspicuous by being surrounded by the expelled fluid which serves as a colourless background to them. The movements of the masses are, according to De Vries, entirely passive, and are accounted for by the currents of protoplasm, stirring them and washing them to and fro.―P. D.]
