A considerable amount of argentaffin granules was localised in the proximal tubules of the toad kidney. While they were found to give argentaffin, metal chelating and alkaline azo coupling reactions in keeping with the general characteristics of the chromaffin cells, the chromaffin and Gibbs reactions could not be obtained. It is, however, peculiar that the granules gave some acid azo coupling reaction and benzylidene reaction even after formol fixation. Positive fluorescence in ultraviolet light and some other reactions were also obtained to indicate that the compound studied was a tryptamine derivative with a tertiary amine at the end of the side chain.