This study was undertaken as a direct service to the schools of the State of Iowa through the suggestion of Professor Ernest Horn, to whom I owe the greatest debt of gratitude for continuous encouragement and helpful criticism. I wish to thank the superintendents, teachers and pupils who gave so freely of their time and effort in securing the spellings and also the Dean of the Graduate College and the Director of the Extension Division who financed from their budgets the collection and scoring of the data. AcknowIedgments are also made to Dean Russell, Associate Professor Lewis, and Dr. Harry A. Greene for their sympathetic counsel and assistance throughout the progress of the study.....