VJii PREFACE. 



would be in some measure inexcusable, did he not 

 make the attempt. But in undertaking this task— as 

 he has been obliged to search for an arrangement 

 which when adopted should coincide with nature, 

 and as after some time and labour bestowed on the 

 research, he is still unable to lay down any distinct 

 principle or rule by means of which such a classifi- 

 cation may be arrived at — it seems necessary that he 

 should here make a few remarks on systems in ge- 

 neral, as well as on that plan which it has been 

 judged proper to pursue in the following pages. 



If it be true, as has been said, that there are few 

 persons who form an accurate idea of what is meant 

 by a System in natural history, it is equally just 

 that there are still fewer persons who comprehend 

 the exact difference between the Natural and an 

 Artificial System, although the whole science now 

 depends on this distinction being thoroughly under- 

 stood. A celebrated French naturalist 3 has indeed 

 denned a System to be an arrangement of bodies ac- 

 cording to the distinctions taken from the conside- 

 ration of one only of their external parts and pro- 

 perties ; whereas he considers a Method to be an 

 arrangement founded upon distinctions drawn from 

 the form and structure of several of these parts. 

 But so far as relates to their effects on natural hi- 

 story, the author of the following work has had rea- 



aCuvier, Diet, des Sciences Naturelles. Pref. 



