PREFACE. Vll 



There are, however, no difficulties so great but they may 

 be diminished ; and even a determination of the relation 

 which one part of the animated world bears to another, may 

 be simplified by analysis, and an exposition of the principles 

 upon which such relations are to be judged of. 



With this view, in the first place, the value of the 

 characters of which botanists make use are here care- 

 fully investigated, for the sake of pointing out the relative 

 importance of the principal modifications of structure in 

 the vegetable kingdom. In the second place, the charac- 

 ters of the orders are analysed by means of tables, in 

 which the distinctive characters of each are reduced to 

 their simplest denomination. It is true that this kind of 

 analysis is attended by the evil of distracting attention 

 from that general and universal study of organisation 

 which the science demands, thus having a manifest tend- 

 ency to render the Natural System artificial ; and that 

 it is also apt to mislead the inexperienced or incautious 

 observer, in consequence of the many exceptions to which 

 distinctive characters are frequently liable. But such evils 

 are nothing compared with the confusion and perplexity 

 an unaided inquirer must experience in disentangling the 

 distinctions of orders for himself. It should also be borne 

 in mind, that analytical tables are mere artificial aids in 

 investigation, to be abandoned as soon as they cease to 

 be indispensable. Many variations in the form of such 

 tables may be easily made ; and, in fact, the student cannot 

 exercise himself better than in contriving them for him- 

 self, as he may readily do by beginning from some other 

 point than that commenced with here. 



The mode in which the tables of this book are to be 

 employed will be best explained by an example, the reader 

 being supposed to be in possession of the preliminary knoidedge 

 which is afforded by the Introduction. Let a Cistus be the 

 subject of inquiry. Upon examining the tables, the first 

 question which the student must ask himself is, Whether 

 it belongs to Vascular or Cellular plants, to Dicotyledons 



