Phototropism in Conidiobolus, Some Preliminary Observations.

The action spectrum for phototropism of Conidiobolus conidiophores was determined crudely with glass filters and by projecting a spectrum on cultures of the fungus. The active wavelengths (about 400 to 650 mmicro) corresponded in general with those absorbed by extracts containing a pigment with an absorption spectrum characteristic of a porphyrin.