Euglena is a single_celled plantlike protists with an oozing, ever_changing shape. Its bright green color comes from chloroplasts used in photosysnthesis. It propels itself with a single, hairlike flagellum located at its leading end. It磗 attracted to light and finds its way using its red eyespot located near the base of its flagellum. These specimens measure approximately 50 microns in length and were recorded under Nomarski illumination. Their movement has been slowed down due to evaporation of water on the microscope slide.