Side bumps on walking cells.

A. Presented is the root-mean-square speed relative to the substrate of the tip of 20 pseudopods.. B. Images of wild-type walking cells. C. Images of tail-attached wild-type cells. D. Images of gliding gbpD-null cells. In the three cases the frames are static and the dots are placed at fixed positions; the arrows point to moving bumps. Numbers indicate time in seconds.