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MISCELLANEOUS PUBLICATION 1271, U.S. DEPARTMENT OF AGRICULTURE 



have never been able to predict flowering by the 

 leaf positions at any time in relation to an induc- 

 tive dark period. All of these things seem to in- 

 dicate that the photoperiodism clock and the cir- 

 cadian leaf movement clock are quite separate. 



If time allowed, further details of the flower- 

 ing process could be discussed. Interest in the 

 possible extraction of a flowering hormone is 

 high at present, after more than 30 years of fail- 

 ures in attempts to extract it. Dr. Denney and a 

 graduate student of mine are presently working 

 on this problem with a higher level of success 

 than has previously been reported. We are quite 

 excited. 



References 



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