. Ameboid movement. Amoeboid movement; Amoeba. AMEBOID MOVEMENT 119 zzi. Figure 39. The path of an Amoeba duhia in comparatively low tem- perature (18° C). The large number of loops and deep waves in the path are due to the low temperature. The experiment was performed under light controlled conditions. Length of the ameba, 350 microns. become transformed into circles. As the temperature decreases, the crests of the waves rise higher and higher, and the bases con- tract more and more, until the two sides of the waves come to- gether, resuUing in the formation of circles (Figure 40). The actual
. Ameboid movement. Amoeboid movement; Amoeba. AMEBOID MOVEMENT 119 zzi. Figure 39. The path of an Amoeba duhia in comparatively low tem- perature (18° C). The large number of loops and deep waves in the path are due to the low temperature. The experiment was performed under light controlled conditions. Length of the ameba, 350 microns. become transformed into circles. As the temperature decreases, the crests of the waves rise higher and higher, and the bases con- tract more and more, until the two sides of the waves come to- gether, resuUing in the formation of circles (Figure 40). The actual size of the wave also decreases at the same time from about eight times the length until it is only two or three times the length of the ameba. Temperature affects therefore the wave mechanism independently of the mere viscosity of the endoplasm. The speed of movement is not merely slowed down, but the character of the waves themselves, is changed. ?; • i Amebas sometimes react to stimuli by moving around the source of the stimulus at a more or less uniform distance through one or more quadrants of a circle, instead of reacting positively, nega- tively, or indifferently, in a definite manner, to the source of the stimulus (Schaeffer '16, '17). See Figure 41. The explanation that has been given by this investigator is that the encircling is due to a balance between the tendency to move ahead in the original direction ("Functional inertia") and a tendency to react positively. But now that we know that amebas tend to form. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Schaeffer, Asa A. (Asa Arthur), b. 1883. Princeton : Princeton University Press
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