x EDITOR'S PREFATORY NOTE. 



no overt indication of such departure from the original is given either by different 

 type or otherwise. It is needless to explain that these changes are only such as 

 the advance of botanical knowledge has rendered necessary since the original was 

 written, and that I have never desired to depart from the intention of the author. 

 To the specialist these modifications will be from time to time apparent; the 

 general reader will perhaps treat me with indulgence should he think that in this 

 matter my judgment has been at fault. Though changes occur throughout the 

 volume, I have preserved intact the main conclusions of the author and the facts 

 upon which they are based. To have altered these in any way, even had I been so 

 minded, would have been inconsistent with the duties of an editor and translator. 

 But in the purely systematic portion of the work I have been restrained by no 

 such scruples. Professor Kerner himself regarded that portion of his work as but 

 tentative, and as it was difficult to merely modify, the whole of this portion has 

 been written de novo, from the Thallophytes to the end of the Gymnosperms 

 (pp. 616-728), and in part the Monocotyledons. The exigencies of the serial issue 

 of The Natural History of Plants alone has prevented the re-cast of the Di- 

 cotyledons, which stand with little modification as in the original. For the portion 

 dealing with the class Gamophycece up to the end of the Conjugates (pp. 627-659), 

 I am indebted to my colleague, Mr. A. G. Tansley of University College, who has 

 devoted considerable attention to the group in question. To him I now offer my 

 hearty thanks. The glossary of botanical terms makes claim neither to complete- 

 ness nor originality. Though a large number of the definitions and explanations 

 have been written specially for this book, I have never hesitated to lay published 

 sources under contribution. The laborious task of constructing the index has 

 fallen to Mr. George Brebner, and to him is due the gratitude of such as gain 

 through it direct and ready access to the body of the work. 



F. W. 0. 



KEW, August, 1895. 



