OBJECTIVES: 1. Complete cinematographic sequences in macrocyst formation and germination in Dictyostelium discoideum. Excellent film is at hand covering the early stages of cytophagic cell formation and engulfment of surrounding myxamoebae. Still to be completed, later stages of maturation and germination. 2. Investigate the origin of the cytophagic cells in homothallic strains of D. mucoroides and D. discoideum, i.e., slime molds where pairing of mating types is not required for macrocyst formation. Is or is not cell fusion necessary? 3. Extend current investigation re the influence of different regions of the spectrum and light intensity on the formation of sorocarps vs. macrocysts in Dictyostelium mucoroides and D. discoideum. With few exceptions darkness promotes cyst formation and "white" light promotes sorocarp production in slime molds capable of forming macrocysts. 4. Complete examination, describe and publish description of the new cellular slime mold to be designated Fonticula alba, a member of the subclass Acrasea. 5. Recultivate, study and describe a unique cellular slime mold, now maintained in lyophilized form, that produces Copromyxa-like fructifications following cell aggregation via streaming, the only known example of this in the subclass Acrasea.