Light micrograph of the freshwater eye flagellate Euglena gracilis. Euglena gracilis are unicellular flagellates with a swimming flagellum, an eye spot, chloroplasts with pyrenoid and colourless paramylon grains as reserve material. The cell shape is, as usual in euglenophyceae, highly variable. Culture material of the algae collection at the University of Cologne (CCAC). Microscopic contrast method : Differential interference contrast. Magnification 920x at a print width of 10 cm.