PREFACE 



Three motived run through this book : An 

 tempt to expound the pr< : evolution in objects 



which are familiar and which have not yel been 

 greatly m< »<liii»-< 1 by man : an effort t<> make a Bimple 

 historical record from unexplored fields ; a desire t<» 

 suggest the treasures of experience and narrative 

 which are a part of the development of agriculture, 

 and from which the explorer must one day bring ma- 

 terial for history and inspiration for story. 



It is now more than ten years Bince these studies 

 were begun. Some of the material has been published 

 in bulletins and journals, as indicated at intervals in 

 th<- text ; but the continuity of the effort and the full 

 historical retrospect are first apparent in this hook. 

 The prosecution of the Btudies has demanded the <•«. li- 

 mitation of original sources of information, when 



such have been a tssible, and it has required much 



travel, including a visit to European herbaria in which 

 the types of certain Bpecies of plants are deposited ; 

 and the necessity of these verifications has delayed 

 the publication of tin- work two yean after the com- 

 pletion of the manuscript, ret, the book is onlj a 

 ■ketch. The Bubject has little continuity or homo- 



(vii) 



