- Arnold L. Nelson, Arvid John Johnson, Bradford Knapp, Charles Ellsworth Gage, Curtis Benton, Cyril Oliver Bratley, D. F. Fisher, E. H. Siegler, Edmund Lambert, Floyd Franklin Smith, Forrest Vern Owen, Frederick James Stevenson, George Arceneaux, George McMillan Darrow, Hazel Katherine Stiebeling, James Herbert Beattie, Loyd William Brannon, Robert Roland Farrar, Van E. Romney, Waldo Lee McAtee, Wayne Melville Bever, William Henry Burrows, William Ogilvie Fraser, William Taylor Miller, United States. Department of Agriculture, Arthur Steele Mason, Charles Frederick Clark, Don Juan Slater, Esther Funnell Phipard, Francis Munger, Harry Humfeld, Howard W. Johnson, I. E. Stokes, Jacob Martin Lutz, Joseph Patrick Quinn, Thomas Laffin Baggette, Victor Rickman Boswell, Wesley Pillsbury Flint, Woodrow Wilson Bailey, John McDowell McCown, Lloyd E. Smith, Talbott Elson Clarke
· 1939