. Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic]. Biology. 84 BIOLOGICAL LECTURES. magnification. Such an appearance is not to be observed in a stationary somatic cell. Thus we see that we can, by the introduction of this property of isolation, trace back highly important and seemingly hetero- geneous phenomena in cell life to a common cause. After this digression we may return to the excretophores. The imbedding of foreign particles in the cytoplasm of the excretophores is only the first step in a series of important changes in these cells, which finall
. Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic]. Biology. 84 BIOLOGICAL LECTURES. magnification. Such an appearance is not to be observed in a stationary somatic cell. Thus we see that we can, by the introduction of this property of isolation, trace back highly important and seemingly hetero- geneous phenomena in cell life to a common cause. After this digression we may return to the excretophores. The imbedding of foreign particles in the cytoplasm of the excretophores is only the first step in a series of important changes in these cells, which finally terminate in the disintegra- tion of the latter. Let us suppose that an excretophore has by mere mechanical action imprisoned in its plasm a number of solid excretory particles. The isolability of the plasma will soon become mani- fest, and these granules will be surrounded by a fluid secretion of the cytoplasm. The waste products, being indigestible and insoluble, the fluid which surrounds them becomes part of a definitive structure of the cell. This fluid may be water or may be something else. I cannot a priori decide what the chemical value of the secreted fluid is, because I am not sufficiently familiar with the chemism of bioplasma and know nothing about the chemical constitution of the excretory products. What I have seen is this: In Fig. i I have reproduced a living excre- tophore, which was obtained by teasing out a part of a living animal (Nephelis quadristriata), drawn under a very high magnification (hom. imm. mm. comp. oc. 6). In the living cell the cytoplasmic network is not visible, and the nucleus appears only as a light drop sur- rounded by a highly refractive membrane. I have in this figure made a combination, inasmuch as I have added to the drawing of the living cell the nuclear structure {n) and the cytoplasmic threads {cp) as they appear in a good preparation. The upper. Please note that these images are extracted from scanned page images that ma
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