EDITOR'S PREFACE. 



When I undertook, about a year ago, to prepare a new English edition of this 

 important work, based upon the German edition of 1874, I found that it would be 

 necessary to make considerable alterations and additions if the work were to main- 

 tain in any degree its high reputation as adequately representing the attainments of 

 Botanical Science. It is with the object of maintaining this reputation that 1 have 

 ventured, not without considerable diffidence, to add to and to alter Professor Sachs' 

 work ; but I have been careful to distinguish my alterations and additions either by 

 enclosing them in brackets or by quoting my authority, so that the reader will have 

 no difficulty in recognising them. I cannot flatter myself, however, that I have been 

 altogether successful in my attempt. Complete success could only have been 

 attained by rewriting a considerable portion of the work, but this did not come 

 within my province. 



I found also that nearly the whole of Book I. had already been for some time 

 in print, and that consequently a number of important recent discoveries had not 

 been noticed in it. In order to meet this difficulty I suggested to the Delegates 

 of the Clarendon Press that the first thirty-two pages should be revised and re- 

 printed, and that the additional notes necessary for the completion of Book I. should 

 be incorporated in an Appendix, a suggestion which met with their approval. An 

 opportunity was thus afforded me of adding some further notes and references on 

 the remainder of the work. As it also contains the Corrigenda, the Appendix has 

 come to be an important feature, and I therefore especially recommend it to the 

 notice of the reader. 



I have no doubt that many errors of omission and of commission will be 

 detected ; for these I would beg the reader's indulgence, in so far as I am respon- 

 sible for them. They would have been much more numerous but for the valuable 

 criticisms and suggestions of many friends, among whom I may especially mention 

 Mr. W. T. Thiselton Dyer, Assistant Director of the Royal Gardens, Kew, Mr. D. 

 H. Scott, Assistant Professor of Botany in University College, London, and Mr. F. 

 O. Bower, Lecturer in Botany at the Normal School of Science, South Kensington. 

 To my friend Mr. A. E. Shipley, Scholar of this College, I am much indebted for 

 his kindness in assisting me in the serious labour of preparing the Index. 



S. H. V. 



Christ's College, Cambridge, 

 August^ 1882. 



