Figure 1. Pyrodictium occultum, scanning electron micrograph. The flat, irregularly shaped cells are connected by a network of protein filaments. (Reinhard Rachel and Karl Stetter, Regensburg, Germany.)

Figure 2. Picrophilus torridus and its habitat. The organism was isolated from a sample taken close to the volcano of Kawayu (Hokkaido, Japan). Christa Schleper (University of Vienna) is in the left background. (Photograph: Gabriela Puehler, Munich, Germany.)