Fig. 4. Stability to perturbations.

(a) Fluid is injected from a second pipette (arrow). Waveform sequences for the cis flagellum only are shown (1–3). (Insets) x-y coordinates of a reference point at a fixed arclength. (b) Trajectories veer off the preperturbation limit cycle during one perturbation event. This deviation is sampled at fixed phase as a function of time (c), which accompanies marked changes in the beat frequencies of both flagella (d).