AQUILA. 95 
Genus AQUILA. 
The genus Aquila was established by Brisson in 1760, in his ‘ Orni- 
thologie, i. p. 419. Since Brisson called the Golden Eagle Aquila 
aquila, there can be no doubt whatever that A. chrysaetus is the type of 
the genus. 
The Eagles may at once be distinguished from any other European Birds 
of Prey by their feathered tarsi, which are entirely concealed by feathers 
down to the toes, in this respect resembling most of the Owls. The genus 
Aquila is a cosmopolitan one, containing about thirty species. Nine only are 
found in Europe, of which three are British. Although large and powerful 
birds, the Eagles are not courageous. They feed much on mammals, birds, 
and reptiles. They nestle in cliffs and trees, some members of the genus 
on the ground, making large nests of twigs, turf, wool, and moss, and lined 
with green plants and foliage. Their eggs are from two to three in number, 
varying from pale bluish white to cream in ground-colour, with brown 
markings of various shades, and violet and grey shell-markings. Under- 
neath the ground-colour there is always a pale bluish green, causing the 
shell, when the egg is held up to the light, to appear that colour. 
