1. The European corn borer larva has been shown to require a dietary source of one or more unidentified factors contained in corn leaves, grass juice concentrate, and certain other plant materials. The required factor or factors has been termed the corn leaf factor.
2. The corn leaf factor does not appear to be identical with any of the known B vitamins, or with ascorbic acid, sodium nucleate, citrovorum factor, or carnitine.
3. The corn leaf factor is heat-stable, acid-stable, water-soluble, and dialyzable.