52 INTEODUCTIOtf. 



Respecting the System of Classification adopted in the present 

 volume, BECHSTEIN thus writes : 



In treating of the history of Cage-Birds, many different 

 methods of classifying them presented themselves to my notice. 

 I might, for instance, arrange them partly according to their 

 size partly according to their peculiar qualities. I might 

 first have spoken of those which delight the ear with their 

 song, and then of those which we prize for the beauty of their 

 plumage. I might have divided them into foreign and indige- 

 nous species ; or made a distinction between those which are 

 tameable only when young, and those which may be tamed 

 when full grown. As none of these systems, however, seemed 

 to me to possess any essential advantage over the other, I have 

 decided on one which will be found both clear and methodical. 

 It has moreover the advantage of being analogous to that 

 system usually adopted in ornithological works, which renders 

 a comparison between the following and other accounts of the 

 same bird less difficult. I have only to mention, that birds 

 which possess common characteristics, especially of beak and 

 claws, are arranged in the same species, and that several ana- 

 logous species form an order. Thus the different kinds of Owl 

 belong to one species ; while both Hawks and Owls are arranged 

 together under the order, " Birds of Prey." 



