Abstract: Studies of the mechanism of action of the fungal toxin, Victorin. Dissertation Discovery Company and the University of Florida are dedicated to making scholarly works more discoverable and accessible throughout the world. This dissertation, "Physiological and Ultrastructural Studies of Oat Membranes Treated With Helminthosporium Victoriae Toxin" by Vernon Edward Gracen, was obtained from the University of Florida and is being sold with permission from the author. A free digital copy of this work may also be found in the university's institutional repository, the IR@UF. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation.