THE CLASSIFICATION OF BIRDS 



PROFESSOR NEWTON'S article ' Ornithology ' in the ' En- 

 cyclopaedia Britannica,' and the preliminary sketch of Dr. 

 GADOW in Bronn's ' Thierreich,' contain a digest of, and 

 criticisms upon, the main schemes of classification of this 

 group which have as yet appeared. I shall, therefore, refer 

 the reader to those works for the history of the subject. 

 There can be no question, in my opinion, that birds must 

 be primarily divided into two great divisions, viz. Saururae 

 and Ornithurae, the first to contain Arch&opteryx and possibly 

 Ijaopterijr, the latter the rest of birds, both living and extinct. 

 As to the Ornithurae, while there is a very general agreement 

 with the main subdivisions no one probably will quarrel 

 seriously with the divisions adopted in the present work 

 no one has (to my mind) satisfactorily arranged the different 

 groups with reference to each other. More especially does 

 it appear to me that the majority of ornithologists are in 

 error concerning the position of the picarian and passerine 

 birds. 



In considering a scheme of classification it is clear that 

 we must bear in mind indications of the descent of birds. 

 Existing schemes have savoured too much of a mere sorting 



O O 



by combining in various ways characters which are dis- 

 tinctively bird characters. However unsuccessful the con- 

 struction of phylogenetic trees has been, it is abundantly 

 plain that that must be the line to take in arranging a group 

 scientifically. It follows, therefore, that in sketching, at 

 any rate, the main outlines of our scheme attention must 

 be paid only, or chiefly, to those characters which birds 

 have inherited from their reptilian ancestors. 



