PLANT HORMONES 227 



4. Boy sen- Jensen, P., "Die Bedeutung des Wuchsstoffes fiir das Wachstum und die 



geotropische Krummung der Wurzeln von Viciafaba," Planta, 20 : 688-698 (1933). 



5. Cholodny, N., "Uber die hormonale Wirkung der Organspitze bei der geotropischen 



Kriiminung," Ber. Deutsch. Bot. Ges., 42 : 356-362 (1924). 



6. , "Beitriige zur Analyse der geotropischen Reaktion," Jahrb. Wiss. Bot., 65 : 



447-459 (1926). 



7. , " Wuchshormone und Tropismen bei den Pfanzen," Biol. Zentralbl, 47 : 604- 



626 (1927). 



8. Darwin, C, "The power of movement in plants," 592 pp., D. Appleton & Co., 



London, 1881. 



9. Denny, F. E., J. D. Guthrie, and N. C. Thornton, "Effect of the vapor of the methyl 



ester of a-naphthaleneacetic acid on the sprouting and the sugar content of 

 potato tubers," C. B. T. I., 12 : 253-268 (1942). 



10. Dolk, H. E., " t^ber die Wirkung der Schwerkraft auf Koleoptilen von Avena saliva,'' 



Proc. Akad. Wetensch. Amsterdam (Sec. Sci.), 32 : 40-47 (1929). 



11. Gardner, F. E., P. C. Marth, and L. P. Batjer, "Spraying with plant growth sub- 



stances to prevent apple fruit dropping," Science, 90 : 208-209 (1939). 



12. Guthrie, J. D., "Inhibition of the growth of buds of potato tubers with the vapor 



of the methyl ester of naphthaleneacetic acid," C. B. T. I., 10 : 325-328 (1939). 



13. , "Control of bud growth and initiation of roots at the cut surface of potato 



tubers with growth-regulating substances," C. B. T. I., 11(1939) : 29-53 (1940). 



14. Hitchcock, A. E., " Indole-3-n-propionic acid as a growth hormone and the quanti- 



tative measurement of plant response," C. B. T. I., 7 : 87-95 (1935). 



15. , "Tobacco as a test plant for comparing the effectiveness of preparations con- 

 taining growth substances," C. B. T. I., 7 : 349-364 (1935). 



16. , and P. W. Zimmerman, "Absorption and movement of synthetic growth 



substances from soil as indicated by the responses of aerial parts, C. B. T. I., 

 7 : 447-476 (1935). 



17. , , "The use of green tissue test objects for determining the physiological 



activity of growth substances," C. B. T. I., 9 : 463-518 (1938). 



18. , , "Unusual physiological responses induced on intact plants by capping 



with black cloth," C. B. T. I., 10 : 389-398 (1939). 



19. , , "Comparative activity of root-inducing substances and methods for 



treating cuttings," C. B. T. /., 10 : 461-480 (1939). 



20. , , "Effects obtained with mixtures of root-inducing and other substances," 



C. B. T. I., 11 : 143-160 (1940). 



21. , , "Further tests with vitamin Bi on established plants and on cuttings," 



C. B. T. I., 12 : 143-156 (1941). 



22. , , "Root-inducing substances effective on apple cuttings taken in May," 



Proc. Am. Soc. Horl. Set., 40 : 292-297 (1942). 



23. Kirkpatrick, H., Jr., "Propagation of poinsettia from cuttings," Flor. Exch., 



92(2) : 16 (Jan. 14, 1939). 



24. , "Propagation of lilacs on own roots," Am. Nurseryman, 69(7) : 3-4 (April 1, 



1939). 



25. , "Value of root-inducing substances for carnation cuttings," Flor. Rev., 



84(2161) : 30-31 (April 27, 1939). 



26. — — , "Root-inducing substances -as an aid in propagating dahlias," Bui. Am. 



Dahlia Soc. (Ser. 14), No. 89 : 9-11 (1939). 



27. , "Additional information on the use of root-inducing substances as an aid in 



propagating dahhas," Bull. Am. Dahlia Soc. (Ser. 14), No. 92 : 10, 19 (1940). 



28. , "Effect of indolebutyric acid on the root response of evergreens," Am. Nursery- 

 man, 71(8) : 9-12 (1940); also in B. T. I. Prof. Pap., 1 : 273-280 (1940). 



29. , "Rooting rose cuttings with chemicals," Am. Nurseryman, 72(10) : 7-9 



(Nov. 15, 1940); also in B. T. I. Prof. Pap., 1 : 291-296 (1940). 



