624 A. W. Gahton and D. C. McCitne 



6. Galston, A. W., and Hand, M. E. Studies on the physiology of light action. I. 

 Auxin and the light inhibition of growth. Amer. Jour. Bot. 36: 85-94. 1949. 



7. , and Warburg. H. An analysis of auxin-gibberellin interaction in pea 



stem tissue. Plant Physiol. 34: 16-22. 1959. 



8. Haan, I. de, and Gorter, C. J. On the differences in longitudinal growth of 

 some varieties of Pisiim sativum. Rec. Trav. Bot. Neerl. 33: 434-446. 1936. 



9. Hayashi, T., and Murakami, Y. Studies on the physiological action of gibber- 

 ellins (Part I). Bui. Nat. Inst. Agr. Sci. Japan. 7D: 159-197. 1958. 



10. , Murakami, Y., and Matsunaka, S. Biochemical studies on bakanae 



fungus. XXXVI. The physiological action of gibberellin. VIII. Changes in the 

 activities of various enzymes in leaf sheaths of rice plants treated with gib- 

 berellin. Bui. Agr. Chem. Soc. Japan. 20: 159-164. 1956. 



11. Jermyn, M. A., and Thomas, R. Multiple components in horse-radish peroxi 

 dase. Biochem. Jour. 56: 631-639. 1954. 



12. Kamerbeek, G. A. Peroxidase content of dwarf types and giant types of plant. 

 Acta Bot. Need. 5: 257-267. 1956. 



13. Kondo. K., and Morita, Y. Phytoperoxidase. II. Isolation and purification of 

 sweet-potato peroxidases and their absorption spectra. Bui. Res. Inst. Food 

 Sci. Kyoto Univ. 10: 33-45. 1952. 



14. Kuse, G. Necessity of auxin for the growth effect of gibberellin. Bot. Mag. 

 Tokyo. 71: 151-159. 1958. 



15. Luckwill, L. C. Fruit growth in relation to internal and external chemical 

 stimuli. Symp. Soc. Stud. Devel. Growth. 17: 223-251. 1959. 



16. McCune, D. C., and Galston, A. W. Inverse effects of gibberellin on peroxidase 

 activity and growth in dwarf strains of peas and corn. Plant Physiol. 34: 

 116-418. 1959. 



17. Phinnev, B. O. Growth response of single-gene dwarf mutants in maize to 

 gibbercilic acid. Proc. Nat. Acad. Sci. U. S. 42: 185-189. 1956. 



18. Purves, W. K., and Hillman, W. S. Response of pea stem sections to indole- 

 acetic acid, gibberellic acid, and sucrose as affected by length and distance from 

 the apex. Physiol. Plant. 11: 29-35. 1958. 



19. , and Hillman, W. S. Experimental separation of gibberellin and auxin 



action in etiolated pea epicotyl sections. Physiol. Plant. 12: 786-798. 1959. 



20. Ro.ss, H. tibcr die Verschiedenheiten des dissimilatorischen Stoffwechsels in 

 reziprokcM /•,7^//o/ni////-Bastardcn und die physiologischc-gcnetische IJrsache der 

 reziprokcn Unterschiede. I. Die Aktivitat der Peroxydase in reziproken Epilo- 

 6ium-Bastarden mit der Sippe Jena. Zeitschr. Abst. Vererb. 82: 503-529. 1941. 



21. Schroeder, C. A., and Spector, C. Effect of gibberellic acid and indoleacetic 

 acid on growth of exci.scd fruit tissue. Science. 126: 701,702. 1957. 



22. Siegel, S. M., and Galston, A. W. Peroxide genesis in plant tissues and its rela- 

 tion to indoleacetic acid destruction. Arch. Biochem. Biophys. 54: 102-113. 

 1955. 



23. van Overbeck, J. The growth hormone and the dwarf type of growth in corn. 

 Proc. Nat. Acad. Sci. U. S. 21: 292-299. VX^'k 



24. Vlitos, A. J., and Meudt, W. The effect of light and of the shoot apex on the 

 action of gibberellic acid. Contr. Boyce Thompson Inst. 19: 55-62. 1957. 



DISCUSSION 



Dr. Burstrom: Do you think, Dr. Galston, that the change in j)er- 

 oxidase activity, which amounted to something between 25 and 40 

 per cent, can account for an increase in growth by 100 per cent or 

 more? It is diflicult to compare the amounts or the enzyme activities, 



