Abstract‘Pyrethrins’ I and II have been separated on both alumina and silica columns. On alumina columns there is some evidence of the separation of the cinerins from the pyrethrins.Material separated in this way has been used to elucidate separations obtained by chromatography of pyrethrum extracts on paper impregnated with alumina and by paper chromatography of 2: 4‐dinitrophenylhydrazine derivatives of the ‘pyrethrins.’.