Fig. 6

Scanning electron microscopy pictures of dark zones (E–H) and unmarked surfaces nearby (A–D) at various magnifications, in the Hall of the Bulls (central bench) and the Passage (vertical bench). Spherical bacteria are indicated by sb (one in B, many in F), bacteria of various shapes by b (in G and H), fungi by f (in E), and microbial filaments by mf (in D, F–H)