Interconvertible Naturally Occurring Auxins 39 



compounds possibly all come from an ether-insoluble precursor 

 which breaks down spontaneously during the extraction process, or 

 more completely on treatment with alkali. 



It is not clear whether these substances are indole compounds, al- 

 though several indole substances are present in the extracts. The be- 

 havior of X and Z on chromatography and their Rj- values in different 

 solvent mixtures indicate that these are not any of the known indole 

 hormones or indole complexes. 



ACKNOWLEDGMENT 



These investigations were carried out during the tenure of a Sen- 

 ior Government Research Fellowship. I am indebted to the Director 

 of the Department of Agriculture and Fisheries for Scotland, Marine 

 Laboratory for facilities for the work. 



LITERATURE CITED 



1. Audus, L. J., and Gunning, B. E. S. Growth substances in the roots of Pisum 

 sativum. Physiol. Plant. 11: 685-^97. 1958. 



2. Bentley, J. A., and Housley, S. Bio-assay of plant growth hormones. Physiol. 

 Plant. 7: 405-419. 1954. 



3. Britton, G., Housley, S., and Bentley, J. A. Studies in plant growth hormones. 

 V. Chromatography of hormones in excised and intact roots of tomato seedlings. 

 Jour. Exper. Bot. 7: 239-251. 1956. 



4. Fukui, H. N., DeVries, J. E., Wittwer, S. H., and Sell, H. M. Ethyl-3-indole- 

 acetate: an artefact in extracts of immature corn kernels. Nature. 180: 1205. 



1957. 

 5. Teubner, F. G., Wittwer, S. H., and Sell, H. M. Growth-substances m 



corn pollen. Plant Physiol. 33: 144-146. 1958. 



6. Jepson, J. B. Indoles and related Ehrlich reactors, pp. 114-138. hi: I. Smith 

 (ed.). Chromatographic Techniques: Clinical and Biochemical Applications. 

 Heinemann, London. 1958. 



7. . Indolylacetamide — a chromatographic artifact from the natural in- 

 doles, indolylacetylglucosiduronic acid and indolylpyruvic acid. Biochem. Jour. 

 69: 22p. 1958. 



8. Lucas, C. E. External metabolites in the sea. pp. 139-148. In: Marine Biology 

 and Oceanography. Deep Sea Research, suppl. to Vol. 3. 498 pp. 1955. 



9. Saunders, G. W. Interrelations of dissolved organic matter and phytoplankton. 

 Bot. Rev. 23: 389-409. 1957. 



DISCUSSION 



Dr. Bennet-Clark: Do you always get both zones? This looks like 

 an association phenomenon, or is a chemical equilibrium involved? 



Dr. Bentley: You can always pick up both zones. You never get 

 a complete conversion which suggests an equilibrium between the 

 two. When extracts are kept in a deep freeze the two zones will still 

 be obtained after a year or more, indicating stability under these con- 

 ditions. 



