Phycomyces: habituation of the light growth response

Abstract

Phycomyces sporangiophores respond to four distinct physical stimuli: gravity, light, stretch, and an avoidance stimulus. Saturating the organism with a light stimulus so that it does not respond to any additional light program does not decrease its ability to respond to an avoidance stimulus. This demonstrates that the organism has the potential to respond after a saturating light stimulus and that the an avoidance stimulus acts at some point past or parellel or parellel to the light-receiving mechanism.