PIED WAGTAIL. 539 



from the MotacUla alba of Liimrens, with which it had 

 hitherto heen confounded, and, briefly pointing out wherein 

 the differences lie, proposed to name the former after the 

 Author of this work. Shortly afterwards he published some 

 fuller observations on the two birds in the ' Magazine of 

 Natural History' (New Ser. i. p. 459), wherein he said that 

 while engaged upon this group during the publication of his 

 ' Birds of Europe,' he had been surprised to find that the 

 sprightly Pied Wagtail, so abundant in our islands at all 

 seasons, could not be referred to any described species, and 

 that it was very limited in its habitat ; for, beside the 

 British Islands, Norway and Sweden were the only parts of 

 Europe whence he had been able to procure examples iden- 

 tical with our bird, whose place was elsewhere in Europe 

 supplied by the true M. alba ; which, although abundant in 

 France, particularly in the neighbourhood of Calais, had 

 never then been discovered in any part of England. "■ The 

 characters by which these two species may be readily distin- 

 guished ", Mr. Gould goes on to say, are the somewhat more 

 robust form of the Pied Wagtail, which "in its full summer 

 dress, has the whole of the head, chest, and back, of a full deep 

 jet black ; " while in M. alba, at the same season, " the throat 

 and head alone are of this colour, the back, and the rest of the 

 upper surface, being of a light ash-grey. In winter the two 

 species more nearly assimilate in their colouring;" the black 

 back of the Pied Wagtail being grey at that season, although 

 never so hght as in M. alba. Mr. Gould concludes by citing 

 as additional evidence of the distinction that the female of 

 our Pied Wagtail " never has the black back, as in the male ; 

 this part, even in summer, being dark grey ; in which respect 

 it closely resembles the other species." 



Such being the grounds on which the Pied Wagtail was 

 separated from M. alba, it has been on the whole acknowledged 

 to be a good species ; but, before considering that some- 

 what important question, it is needful to remark that the 

 difference between the two birds is thought to have first been 

 observed by Briinnich, who, in 1764 (Orn. Bor. p. 70), 

 appended to his notice of the ordinary M. alba the descrip- 



