NOTE ADDED IN PROOF 



As A by-product of visits to controlled environment facilities, I have 

 had the opportunity during the spring of 1963 to visit a number of 

 scientists working on the physiology of flowering in Europe, Great 

 Britain, and Russia. Although their results might be considered 

 mostly preliminary, they provide such a good insight into what might 

 be expected in the near future in this field, that I am unable to 

 refrain from mentioning a few examples. 



A number of workers, especially W. W. Schwabe at Wye College 

 in England, are experimenting with new plants which might provide 

 novel approaches to the flowering process. S. J. Wellensiek and 

 J. Doorenbos at Wageningen in Holland have an active research 

 group. One of their students has evidence that the long-day inhibitor 

 (see pages 1 56-8) is a translocatable substance. In addition, they are 

 quite convinced that response to cold in vernalization requires the 

 presence of dividing cells (pp. 52, 194, and 198). Workers at Imperial 

 College in London also hope to look into this question. They are 

 further interested in nucleic acid metaboHsm as it relates to induction. 

 This problem, as well as the role of nucleic acids in transformation 

 of the bud, is being actively investigated at a number of laboratories. 

 Cellular nucleic acid metabohsm is being studied at Liege in Belgium 

 (where I was also very impressed with photomicrographs of trans- 

 forming meristems), and J. Heslop-Harrison at Birmingham in 

 England has interesting microanalytical results with transforming 

 buds. R. G. Butenko, working in Chailakhyan's laboratory in 

 Moscow, has been able to induce flowering in isolated stem tips by 

 appUcation of kinetin or a mixture of RNA nucleotides. 



A number of laboratories have promising results with extractions. 

 We can hope for breakthroughs in this area. Extractions made in 

 Chailakhyan's laboratory have provided further evidence that a 

 product of long-day treatment is gibberelhn (pp. 60-1). Chailakhyan's 

 two-hormone theory seems to be on a better footing than is imphed 

 by my mention of it on p. 61. He points out that only the evidence 

 for the short-day component still lacks conformation by extraction. 



216 



