title: PHOTIC ORIENTATION BY TWO POINT-SOURCES OF LIGHT.
abstract: General formulae are derived for the orientation of phototropic organisms in a field illuminated by two point-sources of light in the same horizontal plane. It is shown that formulae previously found may all be derived as special cases of these general equations.
authors.affiliation: Laboratory of General Physiology, Harvard University, Cambridge.
authors.forename: W H
authors.initials: WH
authors.lastname: Mitchell
authors.forename: W J
authors.initials: WJ
authors.lastname: Crozier