The joint application for an extension of time for filing answering briefs and for allowance of time for filing reply briefs is granted. Answering briefs shall be filed on or before June 15, 1964, and reply briefs shall be filed on or before July 30, 1964. The motion of Carl Whitson for leave to file a petition for intervention is denied but the alternative motion for leave to file a brief, as amicus curiae, is granted.