xx INTRODUCTION. 



That a certain system has been followed, if we allow design at all, 

 must be admitted, but the exponent of the natural system Sharpe, 

 Gadow, Seebohm and others too numerous to mention notwith- 

 standinghas yet to appear. " The tendency of the present age is to 

 accumulate facts, and not to generalize, but we have now a sufficiency 

 of facts, and want our Lyell to explain them." 



By the consent of most naturalists, all objects of nature are divided 

 jiito kingdoms, sub-kingdoms, classes, orders, families, and genera, 

 and, in some cases, where the families are numerous, tribes, sub- 

 families, and sub-genera are added. Birds are a class of the sub- 

 kingdom Vertebrata, of the Animal kingdom. The Orders of birds 

 are founded chiefly on the form of the bill, and more especially of 

 the feet. Families are characterized by more minute distinctions of 

 the bill and feet, together with characters drawn from the wings, tail, 

 and certain habits, more or less common to all. A genus comprises 

 one or many species closely resembling one another in the structure 

 of bill, feet, wings and tail, and in habits, yet differing, it may be, in 

 colour, size, or some minute differences of structure. To give a 

 familiar example, the European Kite and the common Kite of India 

 are species of the same genus, Milvus ; and the English Kingfisher 

 and the little Indian Kingfisher, are separate species of the same 

 genus Alcedo, each of these genera containing several species. 

 Of late years genera have been greatly divided and multiplied, some 

 of them being classed as sub-genera ; but, in practice, and till the whole 

 realm of Ornithology is presided over by a master hand, no distinc- 

 tion can be satisfactorily pointed out, or acted on. When the 

 families of any order are very numerous, they are classed in tribes ; 

 and when the genera of any family are numerous, or comprise 

 several distinct forms, they are grouped into sub-families. 



In every natural assemblage of forms, whether it be genus, family 

 or order, there is some one form which presents the characters that 

 are common to all, in a more remarkable and complete manner than 

 the rest ; and this is called the type of the group. Thus each 

 genus has its typical species ; each family its typical genus, and so 

 >n ; the type being, in each instance, that form to which our minds 

 naturally revert as best exhibiting the characters that belong to the 



