Zones with similar Rf to gibberellic acid (GA) on chromatograms of ethylacetate extracts of dwarf French bean and potato leaves and stems and lettuce heads all promoted growth of disks of etiolated dwarf French bean leaves in darkness. The presence of a gibberellin was confirmed by tests with stems of dwarf pea, but that the substance was not GA was shown by the lack of effect in the tests with lettuce hypocotyls. The tests with dwarf maize, effects on d-3 and d-5, but not d-1, identified it as gibberelliin A5 (bean factor II). Material that promoted the growth of lettuce hypocotyls occurred in zones close to the starting-line of chromatograms of extracts of bean and lettuce leaves. Calibration of the growth tests with GA gave an estimate of the gibberellin content of the tissues extracted. In the dwarf-pea test the apparent gibberellin contents were similar to the values in the leaf-disk test, but very low values occurred in the maize tests.