PREFACE. IX 



The plan adopted, independently of the part now 

 adverted to, is this : To every collection of orders, whe- 

 ther called class, division, subdivision, tribe, section, or 

 otherwise, such remarks upon the value of the characters 

 assigned to it are prefixed as the personal experience of 

 the Author, or that of others, shews them to deserve. To 

 every order the Name is given which is most generally 

 adopted, or which appears most unexceptionable, with its 

 Synonymes, a citation of a few authorities connected with 

 each, and their date : so that, from these quotations, the 

 reader will learn at what period the order was first noticed, 

 and also in what works he is to look for further informa- 

 tion upon it. To this succeeds the Diagnosis, which 

 comprehends the distinctive characters of the order re- 

 duced to their briefest form, and its most remarkable fea- 

 tures, without reference to exceptions. The latter are 

 adverted to in what are called Anomalies. Then follows 

 the Essential Character ; a brief description of the order, 

 in all its most important particulars. This is succeeded by 

 a paragraph styled Affinities, in which are discussed 

 the relations which the order bears to others, and the most 

 remarkable circumstances connected with its structure in 

 case it exhibits any particular instance of anomalous organ- 

 isation. Geography points out the distribution of the 

 genera and species over the surface of the globe ; and the 

 head Properties comprehends all that is certainly known 

 of the use of the species in medicine, the arts, domestic 

 or rural economy, and so forth. A few genera are finally 

 named as Examples of each order. 



The arrangement of the orders is not precisely that 

 of any previous work, nor indeed do any two Botanists 

 adopt exactly the same plan ; a circumstance which arises 

 out of the very nature of the subject, the impossibility of 

 expressing affinities by any lineal arrangement (the only 

 one which can be practically employed), and the different 

 value that different observers attach to the same charac- 

 ters. This is, however, of no practical importance, so 



