The menacing form depicted in this dramatic photograph is not some giant glob of man-eating protoplasm from a science-fiction film. It is actually a hamster's kidney cell magnified 15,000 times by a scanning electron microscope. Such scientific snapshots taken by Caltech Biologist Jean-Paul Revel may offer an important clue to a mystery that has long puzzled scientists: how a living cell moves across a surface. The cell's perambulations, Revel says, are apparently made possible by a strange phenomenon called "ruffling."
According to Revel's interpretation of the photos, the cell sprouts thin, veil-like folds along its forward edge—that is, in the direction of...