Coloured scanning electron micrograph (SEM) of microorganisms in a sample of wet soil. At centre is a ciliate protozoan and at left is a Korotnevella sp. amoeba. This amoeba has small scales all over its surface, which appear as a net pattern. Amoeba are unicellular protozoa with a flexible outer membrane that allows the organism to alter its shape, primarily by extending and retracting pseudopods. With these pseudopods they engulf food (bacteria, or other microorganisms). Ciliates are single-celled organisms that are covered in hair-like cilia. The cilia are used for locomotion and to move food to the mouth pore. The surrounding humus is permeated by fungal hyphae (brown) and bacteria (yellow, orange, red). This sample comes from the National Park Northern Black Forest, Germany. Magnification: x2400 when printed at 15cm wide.