208 R. M. SAMISH 



which seems to occur in many plants, as a number of ahphatic 

 acids, unsaturated polyhydroxy fatty acids, azalaic acid and 

 scopoletin. 



As more of these substances and their enzymatic mechanisms 

 become known, we will start to tread on more solid ground, 

 whereas today we are dealing with uncertain hypotheses. Up to 

 the present, research has dealt separately with different plant 

 organs, presuming different mechanisms. Wareing and Black^^ 

 have, however, pointed out that apparently the same mecha- 

 nisms act in the different organs of the same plant — obviously 

 there exist morphological modifying factors. 



Permit me a concluding remark in connection with this 

 particular gathering. I was very much impressed by the similarity 

 of processes occurring in the diapause of insects and those 

 which we find with buds of woody plants. Most of us working 

 within relatively limited spheres of research know little about 

 what is going on in disciplines as far removed as entomology 

 from plant physiology. I think that this symposium will have 

 made a considerable contribution by calling attention to those 

 similarities. 



REFERENCES 



1 D. Pelee, M. Sc. Thesis, Hebrew University, Jerusalem-Rehovot, 1951. 



2 W. JoHANNSEN, Def. Kofh Danske Videpsk. Skrifft, 8 (1897) 276. 



3 H. MoLiscH, Sitzber. kgl. preuss. Akad. Wiss., 117 (1908) 87. 



4 K. BoRESCH, Biochem. Z., 202 (1928) 180. 



5 R. M. Samisch, /. Pomol. Hort. Sci., 21 (1945) 164. 



6 E. W. Simon, Biol. Rev., 28 (1953) 453. 



7 U. Bahgat, Ph. D. Thesis, Univ. California, Berkeley, 1931. 



8 W. ^. Garner and H. A. Allard, J. Agr. Research, 23 (1923) 871. 



9 R. J. Downs and H. A. Borthwick, Botan. Gaz., 117 (1956) 310. 



10 P. F. Wareing, Physiol. Plantarum, 3 (1950) 258. 



11 J. P. NiTSCH, Proc. Am. Soc. Hort. Sci., 70 (1957) 526. 



12 J. p. Bennett and F. Skoog, Plant Physiol., /i (1938) 219. 



13 R. M. Samish, Ann. Rev. Plant Physiol., 5 (1954) 183. 



14 T. Hemberg, Physiol. Plantarum, 11 (1958) 610. 



15 P. Spiegel, Bull. Research Council Israel, 4 (1954) 176. 



