1. Several years ago we reported a new type of sugary, "amylaceous sugary," the inheritance of which depends upon two factors, one of which, su₁^am, is allelomorphic to su₁, the other du being located in chromosome 10. The genotype su₁^am su₁^am Du Du is indistinguishable from pure starchy, while the genotype su₁^am su₁^am du du is a good sugary though not as wrinkled and translucent as ordinary sugary. Since the presence of the du gene in homozygous condition can convert su₁^am su₁^am from starchy to sugary, it occurred to us that this same gene might have a similar effect on ordinary sugary, su₁ su₁, converting it to a "super sugary." Chemical analyses of ordinary sugary, su₁ su₁ Du Du and "super sugary," su₁ su₁ du du, have been made which confirm this assumption. The former has 48.7 per cent total sugars, the latter 62.6 per cent. Several commercial sweet corn varieties are now being converted to "super sugary" by introducing the du gene through repeated backcrossing to determine whether this gene will have any value in practical sweet corn breeding.