Mouse Ehrlich ascites carcinoma cells and the amoebaHartmanella castellaniiwere subjected to an acoustic microstreaming field generated around a partially submerged transversely oscillating wire. The various forces responsible for the intracellular “consistency” (i.e., the viscoelastic tendency to resist mechanical deformation) of ascites cells are so strong that the organelles remain attached to each other after the plasma membrane has been torn off, whereas the cell contents of the amoebae are easily dispersed once the plasma membrane is ruptured. Present evidence suggests that the high internal consistency of ascites cells prevents any form of intracellular streaming, whereas the low internal consistency of amoebae might allow artifically induced streaming within the intact cell.