by A. J. Pieters, Archibald Dixon Shamel, Benjamin Ralph Stauber, Chalmers Jackson King, Charles Sidney Leete, Charles Walter Collins, F. M. Grant, Fred Earl Keating, Frederick John Pritchard, Frederick Wulling Herbert, George McMillan Darrow, George Wright Hoffman, Harry Eugene Burke, Harvey John MacAloney, Hazel Katherine Stiebeling, Herman Meserve Johnson, Mary E. Sweeny, Neil E. Stevens, Orville Edward May, Oscar Roland Mathews, Perley Spaulding, Robert Claude Wright, Thomas Moore Whiteman, United States. Department of Agriculture, Walter Cochran Davis, Carl Stone Pomeroy, Charlotte Chatfield, Clarence Elbert Clement, George Fordyce Waldo, Harold Frederick Loomis, Horace Terhune Herrick, James Warren Hubbard, John Raymond Hansbrough, John Valentine Schaffner, Louis Henry Burgwald, Ruth Leah Morgan, Verner Ivan Clark, William Solomon Porte, Frank Nelson Harmon

1931

by Arthur Dickie Borden, Benjamin Yoe Morrison, Caroline Louisa Hunt, Charles Adolph Weigel, Clyde Evert Leighty, Elmer Johnson, Frank Hurlbut Chittenden, Fred Runk Johnson, George Burnap Fiske, Howard Ross Tolley, Jacob Allen Clark, James Herbert Beattie, James Silver, Jason Edward Barr, Leonard Wheeler Kephart, Louis Henry Burgwald, Russell Sage Woglum, Wayne Crocker Nason, Wells Alvord Sherman, William Jeter Phillips, Francis Ezra Cobb, John Holmes Martin, Olnton Dickman Miller

1928