Abstract
Laboratory work on Sphagnum blue-green algal associations is described. The conversion factor between C2H2 reduction and N2 fixation for the system is estimated at 4.5. Heterocyst counts indicate that Sphagnum epiphytic algae have considerably higher N2 fixation per heterocyst than free algae in the same environment. The Sphagnum argustifolium stem transports nitrogen fixed and exuded by Nostoc muscorum upwards.