Phycomyces: Discovery of the Aiming Error in the Avoidance Response

Abstract
When a stage IVb Phycomycea sporangiophore is subjected to an asymmetric avoidance stimulus (a single barrier), it uses its own net rotation to convert the spatial stimulus to a temporal one. This explains the sporangiophore''s nonadaptation to a single-barrier stimulus and adaptation to a double-barrier stimulus.