CLASSIFICATION OF BIRDS. 



Huxley's 

 System. 



Provisional 



classification 



founded on 



Huxley's 



and Sunde- 



vall's 



systems. 



a range of vision wide enough, and a faculty of generalization acute enough, to see the half- 

 dozen or so groups of collateral ranges or outlying spurs, which lead up to, and culminate 

 in, the great central plateau of the Passeres. 



It seems probable that the ornithological Orders of the future will be based upon, or 

 slightly modified from, the four or five great groups which Huxley proposed after his 

 elaborate study of the palatine bones of birds. Of these groups the Schizognathse contain 

 the birds with which I propose to deal in the present volume. It seems to form a homo- 

 geneous assemblage, and would perhaps do so still more if the Pigeons were expelled from 

 it, on the ground that their young are born helpless and naked. The two characters, the 

 arrangement of the palatine bones and the condition of the new-born young, seem to offer 

 a basis for a very simple classification of birds ; and though the latter character may not 

 deserve to be made of so much importance, it will probably be found to be correlated with 

 many other minor characters, the aggregate of which may justify its adoption. 



Birds might then be divided into five Orders, which may be compared to a group of 

 mountains like the Himalayas. The Passeres and their allies represent the great central 

 plateau, around which the other four Orders are grouped, like collateral chains leading down 

 to the plains in various directions. 



These Orders may be briefly summarized as follows : — 



Anseri- 

 f'ormes. 



Order I. ANSERIFORMES. 



Owls, Eagles, Herons, Flamingoes, Ducks, Cormorants, and their allies. 



This group of birds may be roughly defined as Desmognathous Dasypgedes — though 

 many of the Owls are in some respects Schizognathous, and there may be some difficulty 

 in describing the difference in the condition of the young of the Herons and that of some 

 of the Picarian birds. 



Cuculi- 

 formes. 



Order II. CUCULIFORMES. 



Goatsuckers, Cuckoos, Woodpeckers, Parrots, Kingfishers, Hornbills, 

 Rollers, Toucans, Jacamars, Pigeons, and their allies. 



This group of birds contains the Saurognatha? (Woodpeckers), the Schizognathous 

 Gynmopaedes (Goatsuckers and Pigeons), and the Desmognathous Gymnopsedes (the rest). 

 It is very closely connected with the preceding Order by the Storks and Cormorants, 

 which are Desmognathous, and have young born blind and helpless, though covered 

 with down. The Pigeons, being Schizognathous, are nearly allied to the Charadriformes, 

 especially to the Sand-Grouse ; and the Goatsuckers are said to be nearly allied to 

 the Owls. 



