Figure 2. Flagellar beat kinematics of freely swimming Euglena gracilis.

(a) $N=10$ flagellar configurations in evenly spaced instants (phases) within a periodic beat. (b) The same configurations overlapped and color coded according to their phases. (c) Computed torsion $\tau =\tau (s)$ as a function of the flagellar arc length ${\displaystyle s}$. The plot is presented in terms of the normalized quantities $\tau /L^{-1}$ and $s/L$, where ${\displaystyle L}$ is the total length of the flagellum. Panels (a-b) are adapted from Figure 5.E of Rossi et al., 2017.