The developing endosperm of young maize (Zea mays) kernels has proved to be a rich source of readily extracted enzymes suitable for electrophoretic analysis. Isozymes have already been described for alcohol dehydrogenase (Schwartz 1966), catalase (Beckman, Scandalios, and Brewbaker 1964a), esterase (Schwartz 1960), and leucine amino peptidase (Beckman, Scandalios, and Brewbaker 1964b). This communication reports the discovery of electrophoretic variants of a starch-degrading enzyme in extracts of this tissue, and some preliminary breeding tests to establish their mode of inheritance.