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 1. 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 aff'orded 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. 
