title: ON "REVERSAL" OF PHOTOTROPISM IN PHYCOMYCES.
abstract: Alleged reversal of the phototropism of the sporangiophores of Phycomyces by high intensities of light does not occur if infra-red radiation is properly excluded. Phototropic "indifference" alone occurs at high intensities due to equal photic action on both sides of the sporangiophore. If heat radiation is not screened out, a gradual, negative thermotropic bending takes place.
authors.affiliation: Laboratory of General Physiology, Harvard University, Cambridge.
authors.forename: E S
authors.initials: ES
authors.lastname: Castle