IT has been long known that there is no close relationship between the physically and chemically measured action of polygalacturonase1. Jansen and MacDonnel2, Matus3, McColloch and Kertesz4, Reid5, Schubert6 and others have, from very different observations, suggested that the polygalacturonase preparations extracted from micro-organisms and plants contain more than one glycosidically effective pectin enzyme.