The display screen behind the Adviser flicked into a schematic diagram of the Ibis Crater. "Please notice the revised boundary lines," the Sorienti said. "I hope that each of you will avoid trespassing—not merely physically but biologically as well." She looked at them seriously. "Some of you may plan to use herbicides. This is permissible, but the spreading of spray beyond your sector’s boundaries is considered crass. Bacteriological establishment is a subtle art. The spreading of tailored disease organisms is an aesthetic distortion. Please remember that your activities here are a disruption of what should ideally be natural process. Therefore the period of biotic seeding will last only twelve hours. Thereafter, the new complexity level will be allowed to stabilize itself without any other interference at all. Avoid self-aggrandizement, and confine yourselves to a primal role, as catalysts."