PREFACE 



This book has resulted from the cooperative efforts of many different in- 

 dividuals. In September, 1955, the Council of the Botanical Society of 

 America and the members present at the annual business meeting voted to 

 celebrate the fiftieth anniversary of the Society in 1956 by the publication 

 of a Golden Jubilee Volume of the American Journal of Botany. It was 

 also decided that special invitational papers of broad and general interest 

 should be included in as many issues as possible and that these invited con- 

 tributions should be brought together and published as a separate, bound, 

 repaged volume. The 1956 volume (43) of the American Journal of Botany 

 was officially designated as the Golden Jubilee Volume, and each issue was 

 unmistakably identified by a special caption and by a golden cover. Most 

 of the forty papers that compose this book appeared as Special Papers in 

 Volumes 43 and 44 of the American Journal of Botany. 



The Golden Jubilee Volume Committee of the Botanical Society of America 

 was appointed in November, 1955, and charged by the President of the 

 Society, Professor Oswald Tippo, with the responsibility of selecting authors 

 to represent the various fields of plant science and of inviting them to present 

 contributions on the major advances or important developments in botany 

 during the past fifty years, with emphasis on present trends and future prob- 

 lems and on the contribution of plant science to mankind and to his civiliza- 

 tion. The Committee, consisting of George Beadle, John Behnke, Vernon I. 

 Cheadle, Edmund H. Fulling, David Goddard, C. J. Hylander, Oswald Tippo, 

 and William C. Steere, Chairman, hopes that in addition to its value and 

 interest to plant scientists, this volume will enable intelligent nonbotanists to 

 understand and to appreciate what botany is and what botanists are doing. 



Reminiscent of the facetious definition of a camel as "an animal that looks 

 like something designed by a committee," a book written by forty authors — 

 and designed by a committee — very naturally tends to lack uniformity of 

 style and treatment. The papers included in this volume differ as widely as 

 the nature of the authors themselves and vary from rather general surveys 

 to the presentation of the results of original research. The coverage of the 

 whole field of plant science is not as complete as the Committee had planned 



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