IMPERIAL EAGLE. 67 
were hunting together, marked and coloured alike, and therefore no doubt 
a pair. He had often shown in the Great Bastard the difference in 
colour of the primaries as marks of the age of the bird; and any one 
from a casual look would not hesitate to say 'which would be the 
older birds. He is doubtless an empirical naturalist, knows nothing 
of system, but he is a man of very shrewd observation, and whose 
knowledge of the habits of animals is marvellously accurate. He is 
taking an interest in the question himself, and has carefully prepared 
the sternum. As truth is the point to be arrived at, I mention these 
particulars for the information of all interested in the subject." 
In the meantime Lord Lilford and Mr. Howard Saunders, who have 
a most extensive knowledge of the Imperial Eagle, placed their large 
collection of skins of this bird in the hands of Mr. Dresser, and after 
the most careful examination, aided by Mr. Gurney and other well- 
known naturalists, it was the opinion of the gentlemen above mentioned 
that the Imperial Eagle of Spain was a distinct species, always to be 
known by the white on the back being confined to the shoulders of 
the mature bird, and the young having no striated plumage. They 
therefore defined the Spanish Imperial Eagle, as Aquila Adalberti, 
Brehm; his previous application of the name to Aquila ncevioides having 
been discovered to belong to this bird, whose habitat is confined to Spain. 
The bird found in the south-east of Europe, especially Turkey, they 
decided to be also distinct, and to be recognised as a young bird by 
having a striated plumage, and in its mature stage by the white fea- 
thers on the back being confined to the scapulars and none on the 
shoulders. This bird has been named Aquila heliaca, Savigny, and 
its habitat extends from Central Europe to China, and it is of frequent 
occurrence in India. 
The third species is the plainer marked bird, supposed to be pe- 
culiar to India, known as Aquila bifasciata. 
In the meantime the Indian naturalists, Mr. Hume, Mr. Brooks, and 
Mr. Anderson, had been working at the Eagles of India most assiduously. 
Mr. Hume, in his " Scrap Book," has given us an elaborate descrip- 
tion of the four different stages of plumage through which the Imperial 
Eagle (A. heliaca) passes, though in India every stage represents a 
year in the bird's life. These stages may be briefly defined. 
First. A lineated stage, in which the under parts have broader or 
narrower pale centres to the feathers, and the upper parts with pale 
central stripes. (First year.) 
Second. The leading character of this stage is to have two con- 
spicuous white or fulvous white wing bands, while the whole of the 
head, neck, chin, throat, back, lesser scapulars, lesser wing coverts, 
