The naked cells which have been alluded to live in water, and call therefore for no differentiation in connection with this necessity; but those which are surrounded by a cell-wall always develop within themselves a vacuole or cavity which occupies the greater part of their interior, and the hydrostatic pressure of whose contents keeps tha protoplasm in contact with the membrane, setting up a condition of turgidity.
Most plant cells have a single vacuole that takes up much of the cell.
Factors produced by mast cells also caused vacuole formation but not cell death.
Copepod with large oil vacuole, storing energy for the winter months.
The fixation made evident the cytoplasm that surrounds the great central vacuole.