. The Biological bulletin. Biology; Zoology; Marine biology. 452 J. A. DAWSON, W. R. KESSLER, AND J. K. SILBERSTEIN tinues, the sphere becomes slightly elongated. This elongation is a definite indication of the late telophase. From here on the external form of the dividing amoeba may vary. In about 75 per cent of all cases, short, irregular pseudopodia break out at each pole. The re- maining portion of the peripheral protoplasm of the former division sphere (plasmalemma and plasmagel of Mast) remains intact and no pseudopodia are projected from this region. A progressive flowing out occurs at
. The Biological bulletin. Biology; Zoology; Marine biology. 452 J. A. DAWSON, W. R. KESSLER, AND J. K. SILBERSTEIN tinues, the sphere becomes slightly elongated. This elongation is a definite indication of the late telophase. From here on the external form of the dividing amoeba may vary. In about 75 per cent of all cases, short, irregular pseudopodia break out at each pole. The re- maining portion of the peripheral protoplasm of the former division sphere (plasmalemma and plasmagel of Mast) remains intact and no pseudopodia are projected from this region. A progressive flowing out occurs at each end and the pseudopodia of each prospective daughter amoeba become longer and slightly thinner, still, however, remaining noticeably thickened. The cytoplasmic bridge gradually becomes more attenuated, finally forming a fairly long connecting strand (Plate I, Fig. 5). Cytoplasmic currents, as evidenced by the motion of crystals, can be observed to flow, first in one direction and then in the other in. Fig. 6. Amoeba dubia Schaeffer. Total mount. second type of division in A. dubia. See text. X 450. A view of the this connecting strand which now appears quite homogeneous and clear. Just before this strand breaks all motion of protoplasm ceases. Each broken end snaps back toward its respective daughter amoeba, and, be- coming broader and thicker, is gradually withdrawn. In other, fewer cases under apparently similar conditions no long connecting cytoplasmic strand can be seen. Here the pseudopodia are coarser and fewer in number and seem to flow in all directions. Unlike the former type, they are projected from the original central portion which makes the formation of a long connecting strand impossible. In- stead, two wedge-shaped areas progressively pass through and cut off the daughter amoebae (Fig. 6). In such cases the pseudopodia of the daughter amoebae usually obscure the process of fission and it is only possible to know that it has been completed when the daughter c
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