a type of movement characteristic of the protoplasm of leukocytes, amebae, and other unicellular organisms; protoplasm streams to a region of the cell where surface pressure is least and forms a balloon-shaped pseudopod; subsequently, the protoplasm may return to the body of the cell, causing retraction of the pseudopod, or the cell’s entire volume of protoplasm may flow into the pseudopod, therefore causing the cell to move from its previous position to the location occupied by the pseudopod. SYN: streaming movement.