This is a DIC micrograph of cells in a leaf of Elodea canadensis. Cells contain green chloroplasts. The image is linked to an old timelapse video of cytoplasmic streaming, active movement of chloroplasts in the cell. The image above shows the position of chloroplast in dark-adapted cells (uniformly distributed), whereas the timelapse video shows the response of chloroplasts to strong illumination – the chloroplast move to the edge of a cell and start to cycle rapidly.