ABSTRACT
Analysis of high-speed cine-films of Euglena viridis reveal that the organism traverses a complex three-dimensional path while helical waves are propagated from base to tip along the flagellum.
Theoretical analysis shows that the rapid forward velocity of the organism cannot be produced by the body movement alone. The propulsive force generated by the flagellum is sufficient to maintain the observed velocities.
Although the euglenoid flagellum bears mastigonemes the thrust produced by it is in the direction to be expected if the flagellum were smooth. Possible explanations of this observation are given.
The hyperboloid of one sheet is a quadric surface having a finite centre and some of its plane sections hyperbolae (e.g. James & James, 1949). The surface can be generated by a moving straight line. A set of lines lying on a hyperboloid is shown in Fig. 3.
