All moral rights asserted. Recolouring or alteration of the image is prohibited without permission. Bright field light micrograph of a thin section of red onion cells. The whole of each cell vacuole is filled with the violet pigment anthocyanin after this tissue was placed in a salt (sodium chloride) solution. The dilute (hypotonic) salt solution caused water to diffuse into the cell cytoplasm, leading to the cells to become turgid. Compare this image with cells undergoing plasmolysis (shrinkage) in C056/2332. Magnification: x100 when printed at 15 centimetres wide.