INTRODUCTION. 



Were the method which I have judged the most useful in de- 

 scribing birds in no essential respect different from that usually 

 employed, I should not consider it necessary to offer any pre- 

 liminary remarks, but should proceed directly to treat of the 

 various species, supposing the readers of a work like the present 

 to possess a sufficient knowdedge of the terms in common use. 

 The case, however, being very different, insomuch that with 

 respect both to the arrangement of the species, and to the mode 

 of description which I have chosen, some explanations are 

 required to enable the reader to view^ the objects introduced in 

 the same light as that in which they are considered by the 

 writer, I need not apologize for offering here a few observa- 

 tions calculated to facilitate the progress of the former, and to 

 induce him to tolerate what might otherwise seem the not 

 altogether relevant discourse of the latter. The arbitrary, one 

 might almost say mechanical, gradation of arrangement in gene- 

 ral use, though presenting as many modifications as there are 

 writers, appears not to be commonly understood to be of so 

 empirical a character as that in which it presents itself to my 

 view ; I shall therefore, in the first place, offer some observations 

 respecting it, accompanied by remarks on nomenclature. An 

 attempt to communicate as much information regarding the 

 structure of birds, as may render the subsequent descriptions 

 perfectly intelligible even to the unscientific reader, will occupy 

 the second place. Many persons are deterred from studying 



