A Symposium organized by the 

 International Union of Biological Sciences 



with Support of UNESCO 



at the Rothamsted Experimental Station, 



Rothamsted, Harpenden, Herts., England 



November 5-6, 1947 



With Contributions By: — 



D. I. Arnon 



H. BURSTROM 



J. Erkama 

 L. Gisiger 



E. J. Hewitt 

 E. A. Jamalainen 



J. Lavollay 



M. P. LOHNIS 



D. Mulder 



E. G. Mulder 

 B. Nemec 



L. Seekles 



F. Steenbjerg 

 T. Wallace 



INTERNATIONAL UNION of BIOLOGICAL SCIENCES 



Series B • COLLOQUIA • No. 1 

 UNION INTERNATIONALE des SCIENCES BIOLOGIQUES 



