PREFACE 



The present work owes its existence to the favorable reception 

 accorded to Bergen's Foundations of Botany. Whatever better- 

 ments have been suggested by five years' use of the earlier book 

 in the hands of expert teachers will be found here incorporated. 

 The Principles of Botany also attempts to supply what many 

 feel to be one of the most valuable portions of botany for edu- 

 cational purposes, namely, a consecutive series of studies of 

 representative spore plants, so treated as to outline the evolu- 

 tionary history of the plant world. Botanical technology cannot 

 figure largely in any brief general botany. The authors have how- 

 ever touched frequently upon the economic side of the subject, 

 and the last two chapters are wholly devoted to practical topics. 



The subject-matter has been divided into three parts, treating 

 respectively : 



I. The structure and physiology of seed plants (Bergen). 

 II. The morphology, evolution, and classification of plants, being 

 an account of the critical morphology of plants upon which is based 

 their relationship by descent (Davis). 



III. Ecology and economic botany (Bergen). 



The whole will furnish material for a full year's work, and 

 it will usually be found necessary to omit portions and thus 

 shape a course adapted for the exact conditions under which 

 the work in each case is to be done. It is not the intention 

 of the authors to frame an inflexible course, but rather to pre- 



. sent in orderlv fashion the material from which a thoroughlv 



-'.. - i/ 



practical one can be planned. Indeed, the authors believe that 

 a half-year course can be readily arranged by selections from 



the more general sections of the book. 



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