BLUE-THROATED WARBLER. 



485 



Blue-Throated So much difference of opinion prevails among ornithologists as to 



warbler. the generic limitation of the birds here included under Erythacus, 

 that it will not be of much use to attempt to define the genus. For instance, while 

 Professor Newton includes the blue-throated warbler in Ruticilla, Mr. Gates makes 

 it the type of a distinct genus, Cyanecula; and while the same ornithologist 

 separates the nightingales (as Daulias) from the redbreasts, Dr. Sharpe places 

 both in the present genus. We accordingly proceed to notice some of the better- 

 known species without further preliminaries. One of the loveliest of all the 



BLUE-THROATED AND RUBY-THROATED WARBLERS (f nat. size). 



group is the blue-throated warbler (Erythacus suecicus), the Arctic form of which, 

 represented in the woodcut, has the blue gorget spotted with chestnut-red ; while 

 on the other hand the variety of the bluethroat breeding south of the Baltic has 

 the throat spotted with white, or even entirely blue without any spots at all. The 

 Arctic form of bluethroat twice annually crosses the length and breadth of Europe, 

 but it is so seldom noticed on migration through Central Europe as to have given 

 rise to suggestions of impossible distances, conjectured to have been accomplished 

 without rest. It should be observed that Mr. Gates, with whom we are disinclined 

 to agree, regards these two forms as specifically distinct. The Arctic bird reaches 

 its northern breeding-grounds at the end of May, and takes up its residence in 



