Plant Qroivth'Suhstances 



Deuber, C. G. (1923). Amer. Journ. Bot., 13, 276. 



Doak, B. W. (1939). New Zealand Journ. Sci. Tech. ,20, 269A. 



Gillett, S., and Jackson, T. H. (1937). East African Agric. 



Journ., 3, 229. 

 Hubert, B., and Rappaport, J. (1939). Invloed van para- 



phenyleendiamine op de beworteling van stekken. 



Natuurwet. Tijdschr., 21, 56. (Flemish, with EngHsh 



summary). 

 Johnston, S. (1939). Mich. Agric. Exp. Sta. Quart. Bull, 21, 



255- 

 Komisarov, D. A. (1938). Compt. rend. {Doklady) Acad. Set. 



U.R.S.S., 18, 63. 



Laurie, A. (1928). Amer. Florist, 70, No. 2074; after Exp. 



Sta. Record 1928, 58, 838. 

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Landbouwhoogesch. Wageningen, 41, Verh. 2. (Dutch, 



with long English summary). 

 Myers, M. C, Bowden, R. A., and Hardisty, F. E. (1938). 



Science, 88, 167. / 

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14, 365- 

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The actual or possible effect of a number of factors that may 

 affect the production of roots on cuttings treated with syn- 

 thetic growth-substances has been well reviewed by B. 

 Hubert, J. Rappaport, and A. Beke {Meded. Landbouw- 

 hoogesch. OpzoekSta. Gent, 1939, 7, 1-103), who have com- 

 pared most of the methods of application. They appear to 

 prefer the dusting technique, with charcoal as the dust. 



36 



