ON ORNITHOLOGY. 433 



studying a comparatively large number of Pygmy Eagles in 

 Hungary, and on several occasions I saw that the forms 

 which I had before supposed to be Booted Eagles and 

 Pygmy Eagles respectively were represented by a single 

 pair. The habits of the larger birds were the same as those 

 of the smaller, and the variations of colour were also equally 

 common to both. 



In speaking of the colour of this bird I must mention that 

 I have always met with two leading forms, and a third 

 which is only characterized by slight distinctions. The first 

 has the pale plumage with the white breast and underparts, 

 the light brown back, &c. : that is the best known, and, 

 according to my experience, the most common. The second 

 has the uniformly coffee-brown plumage, which varies much 

 in depth of shade among different individuals. The third has 

 the quite dark, almost black-brown dress, which is very rarely 

 met with in our country, and is (according to Louis Bureau 

 in France, and Brehm in Spain) the commoner among the 

 Pygmy Eagles of Western Europe. Among the many Spanish 

 Pygmy Eagles which I saw in the exceptionally rich collection 

 of skins at the British Museum, I also found some specimens 

 with this perfectly dark plumage. 



The mistaken idea that the pale bird is the male, and the 

 dark the female, is still pretty widely spread ; and one of the 

 many extremely interesting points connected with this bird 

 of prey is the very fact that the variations of its colouring, 

 which differ just as much as the plumage of the cock Caper- 

 caillie does from that of the hen, are subject to no law known 

 to us. 



Few European species offer so much material for study as 

 the Pygmy Eagle, and as in Austria, especially in the eastern 

 parts of the country, it is still tolerably common, Austrian 

 ornithologists ought to devote themselves to the study of this 

 bird. 



2F 



