A slipper-shaped ciliate glides a wandering path under darkfield, its whole rim fringed with short cilia that beat in a metachronal wave — a phase gradient running around the body so the strokes look like wind over grass. Inside: an oral groove, two contractile vacuoles filling then snapping empty, a macronucleus and food vacuoles streaming in cyclosis. Every few seconds it fires the avoidance reaction — the cilia reverse, it backs up and turns. Pointer drops an obstacle it swerves around, scroll drives a water current, press jolts it.