About 20 years ago, Bottomley (3), at the University of London, failed to secure normal growth of Lemna and other plants in inorganic salt solutions without the addition of organic matter. He concluded that special compounds, similar to vitamins for animals, were required by plants. These unknown substances were termed auximones. Mockeridge (20, 21) using solutions identical with those employed by Bottomley, found that a decided stimulation of the rate of reproduction of Lemna was produced by various nucleic acid derivatives isolated from soil and manure. Azotobacter and yeast were also found to contain accessories for plant growth, and the possible manufacture of auximones by bacteria was suggested. Opposed to Bottomley and Mockeridge were investigators who denied the essential nature of the auximones while admitting the stimulation factor.
Proceedings of the Iowa Academy of Science
©1940 Iowa Academy of Science, Inc.
Clark, Norman Ashwell and Frahm, Elmer E.
"The Effect of Various Growth-Promoting Substances on the Reproduction of Lemna,"
Proceedings of the Iowa Academy of Science, 47(1), 239-247.
Available at: https://scholarworks.uni.edu/pias/vol47/iss1/46