vi Preface 



evolution, the origin of specific proteins, and the nature of catalytic 

 proteins. The macromolecular aspects of these processes are examined 

 in chapters dealing with cellular organization and the genetic control 

 of cellular organization, witli protozoa as a model system. The final 

 chapters of this hook attempt to illustrate the ways in which cellular 

 interactions and cellular products modify the processes of molecular 

 diversification. 



Throughout these pages we have tried to dissect the fabric of molec- 

 ular and cellular interaction which lead to the bewildering array of 

 biological complexity confronting us. We hope this collection of 

 papers will lend perspective to this area. In some small measure we 

 feel we have accomplished this. 



I wish to thank the contributors to this volume who gave so freely 

 and graciously of their thoughts and time. Thanks are also due Drs. 

 Wilbur Ackermann and M. J. Coon of The University of Michigan, who 

 spent much time in planning the lecture series from which this book 

 is derived. 



John M. Allen 



