title: Biorhythms on cellular and organismic level (introduction).
authors.affiliation: Institut für Allgemeine Botanik und Botanischer Garten der Universität Hamburg, FRG.
authors.forename: D
authors.initials: D
authors.lastname: Mergenhagen
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D013026:Space Flight; D014893:Weightlessness