308 Mr. H. Seebohm on the Genus Sylvia. 



XXVI. Remarks on the Genus Sylvia and on the Synonymy 

 of the Species. By HENRY SEEBOHM. 



THE classification of birds will probably occupy the attention 

 and tax the ingenuity of ornithologists for some years to come. 

 This branch of zoology has undoubtedly made rapid strides 

 during the last half century; but it is nevertheless only 

 within the last generation that its study has emerged from 

 the literary into the scientific stage. Much has been done 

 to illustrate the anatomy and physiology of birds ; their litera- 

 ture and synonymy have been unravelled from much of the 

 confusion into which they had drifted ; and their geographical 

 distribution has been extensively, if not exhaustively, worked 

 out ; but the clue to their classification remains undiscovered. 

 Of every new system of classification which has been pro- 

 posed, one can only say that it is as unsatisfactory as its pre- 

 decessors. One reason of this may be found in the attempt 

 to make a linear arrangement of the families of birds. This is 

 as impossible as to make a linear arrangement of the countries 

 of Europe. A scientific arrangement of birds, classified ac- 

 cording to their natural affinities, cannot be represented by 

 a line, nor yet by a plane, but rather by an inverted cone, of 

 which the base represents the existing avifauna of the world, 

 and the underlying sections the birds of past geological ages. 

 Nor can we assume that the birds at present existing repre- 

 sent a uniform flat plane. There are doubtless deep valleys, 

 which, like the Marsupials of Australia, belong to lower 

 sections, whilst the more rapidly developed families or genera 

 may represent ranges of mountains. Some genera are islands, 

 isolated by the extinction of their nearest allies ; whilst some 

 families represent inland countries, closely connected with 

 many surrounding families. 



The classification of birds thus resembles the fitting together 

 of one of the puzzle-maps of our childhood, with this dif- 

 ference, that we have not only to fit the various pieces to- 

 gether, but we have first to get them into their right shapes. 

 In all probability our knowledge of ornithology is not yet 

 ripe for any classification to be successfully attempted. The 



