Vi PREFACE 



soil sciences. They include specifically the disciplines of microbiology, 

 soil chemistry and soil physics; plant and animal genetics, nutrition, 

 physiology, and pathology; molecular biology and biophysics; ecology; 

 taxonomy; soil conservation; land use; and crop and animal production. 



The subject which was chosen for the dedicatory symposium was 

 Growth. Growth, the essential and peculiar characteristic of all living 

 matter, is by definition a subject of critical interest to workers in all the 

 disciplines accommodated by the new Life Science Building. 



Growth can be studied and understood at many levels. It can be 

 thought of at the levels of nucleic-acid chemistry or the aggregation of 

 cells, in terms of the development of individual organisms or as a 

 phenomenon involving interrelationships between the organism and 

 its environment. Because of its breadth, it seemed particularly suitable 

 as the subject of a symposium which could bring together leaders in a 

 variety of fields, both from this country and abroad, to present papers 

 concerning recent developments in their own and others' research. 



It was clearly impossible to give truly comprehensive coverage to 

 the subject of growth within the space of a three-day symposium. This 

 was not the aim of the Purdue symposium. Its aim, rather, was to offer 

 to scientists in a variety of disciplines some insights into the important 

 work being done in areas other than their own. It was also the purpose 

 of the symposium to suggest the impossibility of understanding so 

 massive and all-encompassing a subject as growth tlirough the ap- 

 proach of a single discipline. 



The speakers, representatives of six nations, offered a penetrating 

 look at the phenomenon of growth in plants, animals, and microorgan- 

 isms, and they provided a searching review of the many unanswered 

 questions which still confront us in this most complex subject. In gen- 

 eral, the symposium was planned as a survey of current research prog- 

 ress at three levels: growth as a molecular phenomenon, growth at 

 the cellular and tissue level, and growth of the whole organism. The 

 first two days of the symposium were occupied by general sessions 

 planned for the entire audience. On the third day, simultaneous papers 

 were delivered in sections more specifically concerned with aspects of 

 animal, plant, and microbial growth and plant-soil relationships. 



The first day's program included the following papers: "Macro- 

 molecules and Natural Selection," by F. H. C. Crick, Cambridge Uni- 

 versity; "The Synthesis of Proteins," by M. B. Hoagland, Massachusetts 

 General Hospital; "The Plan of Cellular Reproduction," by Daniel 

 Mazia, University of California; and "Aspects of Mammalian Cell 

 Growth in Tissue Culture," by Theodore T. Puck, University of Colo- 

 rado Medical Center. The papers by Crick and Hoagland set a basic 



