ON ORNITHOLOGY. 453 



In four very old and perfectly similar birds the iris was 

 sulphur to lemon-yellow in colour, the beak waxy yellow, 

 the cere somewhat the same, but more inclined to citron- 

 yellow, the feet citron-yellow, and the nails black. A fifth 

 showed brownish spots, especially on the under part of the 

 eye, the iris being sulphur-yellow. 



The Sea-Eagle of Southern Europe differs from the 

 Northern Sea-Eagle both in size and colour, but is indis- 

 putably the same bird, and there seem to be no grounds what- 

 ever for making two species of them. They are, however, 

 distinct races, such as are often produced among other mem- 

 bers of the animal-world by different conditions of life and 

 climate. 



In the rich collection of the British Museum I found skins 

 of Haliaetus albicilla in all plumages and from the most 

 widely separated countries. The northern specimens from 

 Scotland, Iceland, Scandinavia, and the north of Russia were all 

 markedly larger than those from the South of Europe, Asia 

 Minor, and the north of Africa ; and the colouring of the 

 former was much more pronounced, being darker in the 

 young plumage, lighter in the old, and in many cases almost 

 white. 



