Along with the development of the conception of vitamins for animals there was introduced the corresponding idea of the necessity of unknown organic substances for plants. These accessory substances, termed auximones, were claimed to be essential for the growth and development of all chlorophyll producing plants. By the use of Lemna major it was found at Iowa State College that this claim was not valid, and that these plants would grow and reproduce successfully in a medium composed of highly purified inorganic salts. The presence of organic matter, however, stimulated the reproduction, and the effect of organic substances has been investigated both in the presence and absence of microorganisms. No stimulation was found in the absence of microorganisms even though organic matter was introduced which improved growth under non-sterile conditions.
Proceedings of the Iowa Academy of Science
©1931 Iowa Academy of Science, Inc.
Clark, Norman Ashwell
"Organic Matter and the Life of the Green Plant,"
Proceedings of the Iowa Academy of Science, 38(1), 168-169.
Available at: https://scholarworks.uni.edu/pias/vol38/iss1/30