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- 
eaillie 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 Hagle, 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 
