. Behavior of the lower organisms. Animal behavior; Invertebrates. THE BEHAVIOR OF OTHER INFUSORIA in A. Flagellata -nu The free swimming flagellates move in a spiral, keeping a certain side of the body always toward the outside of the spiral,1 just as Para- mecium does. By means of the flagella they draw a cone of water from in front to the anterior end of the body, as happens in Paramecium. Among the flagellates the behavior has been most precisely studied in Chilomonas and Euglena (Jennings, 1900, 1900 a and b). Chilomonas. — Chilomonas is an un- symmetrical organism, of an irregularly oblo
. Behavior of the lower organisms. Animal behavior; Invertebrates. THE BEHAVIOR OF OTHER INFUSORIA in A. Flagellata -nu The free swimming flagellates move in a spiral, keeping a certain side of the body always toward the outside of the spiral,1 just as Para- mecium does. By means of the flagella they draw a cone of water from in front to the anterior end of the body, as happens in Paramecium. Among the flagellates the behavior has been most precisely studied in Chilomonas and Euglena (Jennings, 1900, 1900 a and b). Chilomonas. — Chilomonas is an un- symmetrical organism, of an irregularly oblong form. The body is compressed sideways and bears an oblique notch at the broader anterior end (Fig. 72). Of the two anterior angles which He on either side of the notch, one (x) is larger and lies more to the right than the other (y). From the notch arise two long flagella, by the aid of which the animal swims. Chilomonas often occurs in uncounted millions in water containing decaying vegetation. In swimming, Chilomonas revolves on its long axis, at the same time swerving toward the smaller of the two angles at the anterior end (Fig. 72, y). The path followed thus becomes a spiral (Fig. 73). The animal often comes to rest against solid objects; it is then attached by one of the two flagella, while the other is free. To most effective stimuli Chilomonas responds by an avoiding re- action similar to that of Paramecium. Its forward movement becomes slower, ceases, or is transformed into a movement backward. Then the animal turns more strongly toward the side which bears the smaller angle, and finally starts forward again. Thus the path is altered. The reaction consists essentially in pointing the anterior end successively in many directions, toward one of which the animal finally swims. The different factors in the reaction vary with the intensity of the stimula- tion, just as they do in Paramecium. The reaction may be repeated, as in the animal last named, until it finally ca
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