THE BIRDS OF HELIGOLAND 201 



meet only with unlimited gradational stages of mixtures of grey 

 and black forms. 



Such an instance is in fact supplied by the liiu&{Tringa pugnax). 

 The individuals of this species present in their plumage so endless 

 a change of combinations of rust-red and black and white, that it is 

 literally impossible, among hundreds of these birds, to find two 

 exactly like each other, while what would appear to be primary 

 forms of the rust-red, white and black individuals, are among the 

 greatest rarities. 



I assume the primary form of Tringa pugnax to have been of 

 rust-red colour; that, as is the case with most birds, more or 

 less white-coloured individuals were frequently produced — as, for 

 instance, males with a white ruff— and that a black variety was 

 evolved by the pairing of a rust-red bird with a white one. In 

 this view I am supported by my own exjjerience when I was 

 breeding Cochin-China fowls. I possessed a number of beautiful 

 fowls of this variety in their original buft" (rostgelb) colour, and 

 by accident obtained a hen quite normal in form but of a pure 

 white. By crossing this hen with a buff (rostgelb) cock, I obtained, 

 greatly to my surprise, a greater or less number of black descend- 

 ants, ^lany of the young birds were almost quite black ; in others 

 the buff {rostgelb) feathers were only tipped with black ; in the case 

 of the cocks, the black colour had a very intense steel-blue gloss. I 

 repeated these experiments for about four or five years, always 

 with the same result ; after which I got rid of the white fowl, as 

 I prefer to keep only one species, and to maintain that as pure as 

 possible. 



The Carrion Crow as a breeding bird is somewhat unequally 

 distributed from the extreme west of Europe to the extreme east of 

 Asia : however, it does not extend so far north as its grey relative ; 

 thus it is not met with in Scandinavia. According to Seebohm it 

 occurs most numerously in eastern Asia, from the Jenesei to Japan. 



39. — Hooded Crow [Gkaue Krahe]. 



CORVUS COENIX, Linn. 



Heligolandish : Kreih = Crow. 



Corvus comix. Naumann, ii. p. 65. 



Hooded Crow. Dresser, iv. 



Comeille mantelee. Temminck, Manuel, i. p. 109, iii. p. 59. 



As has already been indicated in the case of the preceding 

 species, the Hooded Crow is seen here in great numbers during the 

 two migratory periods of the year ; and more especially during the 



