This is the original movie of a Balamuthia mandrillaris ameba within a culture of monkey kidney cells in the background. The comparatively thick body of the ameba has a number of pseudopodia extending from it and a large prominent nucleus. The action of the pseudopodia is important in the feeding of the amebas. Their tips have a pointed, sharp, dense extension that has been seen to grow out, and move together with a snap (about 1 second). This action is a typical movement of the tips of the pseudopodia. Accompanying photographs are enlargements of the tips of pseudopodia to demonstrate their flexibility and movement, and a second set of photographs that demonstrate the puncture of the plasma membrane of a rounded, clear monkey kidney cell with a large, rounded, clear nucleus with an elongated dense nucleolus. The first shows an indentation in the cell membrane, the withdrawal of the pseudopodia tip and the subsequent rupture of the membrane in the area indented by the amebic tip. The eventual break in the membrane may have resulted from the release of a proteolytic enzyme. Adapted with permission. Details of preparation can be found to accompany CIL:19325.