Preparations of glucan obtained from baker’s yeast and sclerotia of Sclerotinia Libertiana were found to be completely hydrolysed by enzymes of the Sclerotinia fungus. Some differences in the molecular structure of the glucans were found upon examination of the modes of degradation by the successive action of Rhizopus- and Sclerotinia enzyme preparations of which the former had only a partial hydrolytic effect.The dissolution of glucan in intact cells of yeast, that could be estimated from the rate of autolysis of the cells, was proved to be insignificant on the action of glucanase alone in the Sclerotinia enzyme solution. The combined action of glucanase with lipolytic enzyme in the fungus enzyme solution are shown to promote the solubilization of intact yeasts and sclerotium cells.