Vacuole synonyms

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.

In these we have (1) the evaporation from the damp delicate cell-walls into the intercellular spaces; (2) the imbibition by the cell-wall of water from the vacuole; (3) osmotic action, consequent upon the subsequent increased concentration of the cell sap, drawing water from the wood cells or vessels which abut upon the leaf parenchyma.

Eventually the protoplasm usually forms only a lining to the cell wall, and a large vacuole filled with cell sap occupies the centre.

There is no reason to doubt that this vacuole is a normal cell-constituent, for it has been described in parasites in quite normal surroundings and conditions.