LECTURES BY 



NORMAN G. ANDERSON 



Oak Ridge National Laboratory 



THEODOSIUS DOBZHANSKY 



Rockefeller Institute 



J. N. SPUHLER 



The University of Michigan 



G. LEDYARD STEBBINS 



University of California 



C. H. WADDINGTON 



University of Edinburgh 



THE EDITOR 



J. IVES TOWNSEND is 



Associate Professor of 

 Biology and Genetics of the 

 Medical College of Virginia 



