4 Preface 



guage. Numerous topics have been presented in tables so that facts 

 may be learned easily and compared and contrasted with other facts. 

 A new classification of plants is used since it is based on more natural 

 plant relationships, but a contrast with the older method is given in 

 the Appendix. Several new illustrations are included and several others 

 have been revised. Questions and Topics are added at the ends of the 

 chapters to assist the student in testing himself as well as to guide him 

 in his study. Selected References are included for additional reading 

 in case it is deemed necessary. The glossary is extended to include 

 many of the new materials and principles treated in the text. 



To acknowledge all persons who have made contributions toward im- 

 proving the text would make a prohibitive list. Consequently,- the 

 author shall limit his acknowledgments to his immediate colleagues, 

 Professors E. T. Bodenberg, C. A, Brand, and Evelyn Wagner Neal, 

 whose contributions are greatly appreciated. Permission to reproduce 

 numerous illustrations from various sources are acknowledged in connec- 

 tion with each one. The author is indebted to Charles A. Brand and 

 Gerald R. Bradford for certain new illustrations and for corrections in 

 others. The Table of Contents is given in some detail so that the stu- 

 dent may derive a certain degree of orientation and the instructor may 

 be guided in placing major emphasis on certain topics. Justification for 

 the somewhat extensive treatment of the various phases of plant and 

 animal biology is based on presumption that one must understand some- 

 what the various parts of the science of biology in order to comprehend 

 more completely any particular portion of it. The human implications 

 of biology have been presented without attempting to make of this a 

 text in human anatomy, physiology, or psychology. 



William C. Beaver 

 Wittenberg College 

 Springfield, Ohio 



