xiv PREFACE 



It is a pleasure to acknowledge the valuable services of the follow- 

 ing conveners: Dr. W. Arnold, Dr. C, S. French, Dr. R. Y, Stanier, 

 and Dr. C. B. van Niel. Special notes of gratitude are due to Dr. R. K. 

 Clayton and Miss Jane Finney for their editorial assistance and to 

 Mr. Justin C. Crawford for his capable efforts in making the necessary 

 arrangements. The editors are also indebted to those who contributed 

 to the appendices, which contain frequently required experimental 

 data and bibliographies of areas which could not be adequately covered 

 due to lack of time. 



We are particularly grateful to Antioch College for providing an 

 auditorium and other attractive facilities for the symposium, and to 

 the Charles F. Kettering Foundation for financially supporting the 

 symposium. 



The Editors 



