- Reginald D. Forbes, Alvah Peterson, Arthur Truman Semple, Charles Dwight Marsh, Clarence Luther Forsling, Donald Bruce, Edmund Cecil Shorey, Franklin Post Metcalf, Hugh Curtis McPhee, Irvin Carl Feustel, Joshua John Skinner, Josiah Chase Folsom, Karl S. Quisenberry, Lyle Thomas Alexander, Marinus Westveld, R. W. Leukel, Richard Edwin McArdle, Stuart Bevier Show, Theo. H. Scheffer, Thomas Roy Truax, Walter Carter, Wilbur Clifford Edmundson, William Henry Black, A. B. Clawson, E. I. Kotok, Edwin Alfonso Trowbridge, H. E. Dvorachek, Horace Greeley Byers, K. D. Jacob, K. F. Warner, Lester Henry Reineke, O. N. Eaton, Charles Vinyard Wilson
· 1931
- Charles A. Fort, Charles Chase Hill, David Francis Costello, David Irving Blumenstock, Doys Andrew Shorb, Elmer R. Roth, Ethelbert Lee Langsford, Everett Elmer Wehr, Frank M. Eaton, Horace Preston Lanchester, Irvin Carl Feustel, Leander D. Howell, Lucy Maclay Alexander, Lyle Thomas Alexander, Mark Hughlin Haller, Milton Henry Fohrman, Robert Edgar Worthington, Roy Hyer Canfield, Stafford Coleman Happ, Thomas Randall Carson Wilson, United States. Bureau of Plant Industry, Vernon Webster Johnson, William Gustavus Wahlenberg, Bailey Sleeth, Ben Hur Thibodeaux, Gordon Rittenhouse, Horace Greeley Byers, John Stuart Pinckney, L. V. Wilcox, Nancy Griswold Clark, Nelson McKaig, Paul Lewis Harding, R. R. Graves, Raymond Price, Sidney Henderson, Smith Winford Greene, Edgar John Udine, Gilbert Colfax Dobson, Glen Edgington, Hiram Richard Reed, James Hayes Marshall
· 1940
- Carl S. Scofield, Archibald Dixon Shamel, David A. Savage, David Leroy Yarnell, E. C. Tullis, Earl Dewey Mallison, Frederic Gordon Renner, Frederick Lovejoy Wellman, Hazel Edith Munsell, Horace Greeley Byers, Howard Barrett Richardson, Irvin Carl Feustel, Johnson Thatcher Sarvis, Joseph Heilman Shollenberger, Mason August Hein, Maxon Young Pillow, Myron Sallee Anderson, Norman Julian Wall, Percy Hoke Royster, T. D. Jarrell, Theodore Comstock Scheffer, Thornton Taft Munger, Walter Huber Meyer, William Henry Black, Alonzo Charles Cook, Carl Stone Pomeroy, Charles Lloyd Moon, E. A. Gorman, Grace Margaret DeVaney, James McKenzie Hankins, James Richard Quesenberry, John Carl Thysell, Ronald Floyd Luxford, Thomas L. W. Bailey, Alfred Leroy Baker, Carl Marcus Conrad, Elmer W. Knight, Fletcher Pearre Veitch, Mary Hanford Kennedy, Ralph Emerson Caryl, William Virgil Hukill
· 1937
- A. B. Clawson, Arthur Frederick Sievers, C. H. Batchelder, C. J. King, Chase Going Woodhouse, Frederick Charles Scobey, Glenn Sanborn Smith, Hugh Hackland Darby, Irvin Carl Feustel, Irvin Cecil Brown, James Robert Douglass, John Guice Sutton, John William Strowbridge, Leander Scales Stuart, M. A. Crosby, M. S. Anderson, Milo Nelson Wood, Norma Lenys Pearson, Orville Alva Faris, Robert Claude Wright, Samuel Fortier, William Henry Black, Arthur Appleton Young, David Dewitt Questel, Edwin Alfonso Trowbridge, Eleanor Muriel Kapp, Faith Moors Williams, Horace Greeley Byers, Jacob Allen Clark, Morris Samson Lowman, Ralph Wylie Frey, Thomas Donnelly Rice, Walter M. Peacock, Lawrence Henry James, Thomas Moore Whiteman
· 1933
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Charles A. Fort, Charles Chase Hill, David Francis Costello, David Irving Blumenstock, Doys Andrew Shorb, Elmer R. Roth, Ethelbert Lee Langsford, Everett Elmer Wehr, Frank Morris Eaton, George Charles Husmann, Harold Reginald Offord, Horace Preston Lanchester, Irvin Carl Feustel, Leander D. Howell, Lucy Maclay Alexander, Lyle Thomas Alexander, Mark Hughlin Haller, Milton Henry Fohrman, Robert Edgar Worthington, Roy Hyer Canfield, Stafford Coleman Happ, Thomas Randall Carson Wilson, Vernon Webster Johnson, William Gustavus Wahlenberg, Bailey Sleeth, Ben Hur Thibodeaux, Elmer Snyder, George R. Van Atta, Gordon Rittenhouse, Horace Greeley Byers, John Stuart Pinckney, L. V. Wilcox, Nancy Griswold Clark, Nelson McKaig, Paul Lewis Harding, R. R. Graves, Raymond Price, Sidney Henderson, Smith Winford Greene, Edgar John Udine, Frederick Ludwig Husmann, Gilbert Colfax Dobson, Glen Edgington, Herman Eugene Swanson, Hiram Richard Reed, James Hayes Marshall· 1939
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No image available
No image available
Alvah Peterson, Arthur Truman Semple, Charles Dwight Marsh, Clarence Luther Forsling, Donald Bruce, Edmund Cecil Shorey, Franklin Post Metcalf, Hugh Curtis McPhee, Irvin Carl Feustel, Joshua John Skinner, Josiah Chase Folsom, Karl S. Quisenberry, Lyle Thomas Alexander, Marinus Westveld, R. W. Leukel, Reginald D. Forbes, Richard Edwin McArdle, Stuart Bevier Show, Theo. H. Scheffer, Thomas Roy Truax, Walter Carter, Wilbur Clifford Edmundson, William Henry Black, A. B. Clawson, E. I. Kotok, Edwin Alfonso Trowbridge, H. E. Dvorachek, Horace Greeley Byers, K. D. Jacob, K. F. Warner, Lester Henry Reineke, O. N. Eaton, Charles Vinyard Wilson· 1930
No image available