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central portion yellowish brown; lower part of the back; rump, and upper tail-coverts washed with 

 rufous here and there, the latter having the terminal portion dull yellowish white ; tail dark brown, 

 tipped with dull light brown ; quills blackish brown ; secondaries broadly tipped with dirty yellowish 

 white ; larger wing-coverts dark brown, tipped with dirty white ; smaller coverts similar to the back ; 

 chin and throat sandy yellow, unstriped ; breast and underparts generally (excepting the thighs, tarsi, 

 and under tail-coverts, which are pale, unstriped, yellowish buff) pale yellowish buff or honey-yellow, 

 every feather edged with dark brown, giving a very distinct striated appearance; soft parts as in 

 the adult. 



Obs. For long no little confusion has existed regarding the various stages of plumage which the Eagles 

 undergo; and as yet very little is known respecting the immature dress of several species. Aquila 

 mogilnik is, when first hatched, covered with snow-white down, from which it passes into a plumage 

 similar to the young bird last described, but darker. Dr. E. Eversmann (Cab. Journ. i. p. 59) brought 

 up young birds, to watch their chauges of plumage, and states that its first feather-plumage resembles 

 very closely that of the bird figured by Naumann, but is darker, and not so red. I have before me a 

 specimen collected by Canon Tristram at Lebanon, evidently a very young bird, and considerably 

 darker than any other example I have examined ; and I surmise that this is the first stage referred to by 

 Dr. Eversmann. From this it passes, probably not by moult, but merely by fading of the colours of 

 the feathers into the pale honey-brown striated stage. Between this last and the dark blackish brown 

 mature plumage there is one stage in which it resembles the immature Aq. adalberti, but may readily 

 be distinguished by the total absence of any white on the edge of the wing. In this stage it is dull 

 reddish or earthy brown, blotched all over with blackish brown, and in most specimens the tail and 

 head have to some extent assumed the fully adult dress. How long it takes the bird to pass through 

 all stages of plumage from the down to the fully adult dress I cannot state with certainty, but think 

 that it will be found to be about four years. 

 Messrs. Brooks and Anderson sent over to mc some time ago a very large series of Indian Eagles to prove 

 that Aq. bifasciata and Aq. mogilnik (the latter called by them Aq. crassipes) are distinct ; and I have 

 made use of these specimens, which are now in the Norwich Museum, both in the preparation of the 

 present article and also in demonstrating, in December 1872 {vide P. Z. S. 1872, p. 863), that the Indian 

 and East-European Imperial Eagles are the same, and that the Spanish Imperial Eagle is a distinct and 

 Clearly recognizable species. In this Indian series are five specimens of Aquila mogilnik, numbered by 

 Mr. Brooks according to the order in which he considers they should come, beginning at the youngest. 

 Of these, no. 1 is in the first or striped plumage, with the light tips to the secondaries, and plain un- 

 striped lighter-coloured tail, tipped with dull dirty buff, and having dirty yellowish tail-coverts. No. 2 

 has blotches of black all over the underparts, and resembles Aq. adalberti in the same stage of plumage ; 

 the centre tail-feathers are slightly marbled and much abraded and worn; and fresh blackish brown 

 feathers are showing here and there on the back. No. 3 has the entire plumage much darker and the 

 head fighter ; the quills are blackish brown ; and the tail is as in the fully adult bird, except that it is 

 slightly tipped with dirty white. No. 4 is in the adult plumage, except that there is no appearance of 

 the white feathers on the scapulars. No. 5 is a fully adult bird, and, excepting one which Baron von 

 Hiigel has kindly forwarded for examination, which it very closely resembles, is the finest specimen I 

 have ever had an opportunity of handling. It has the head and nape creamy yellow, marked with pale 

 rusty yellow ; back, wings, and entire underparts nearly black ; scapulars chiefly pure white ; on the 

 edge of the carpus the feathers are narrowly margined with dirty brownish yellow, but there is no sign 

 of any white feathers ; the upper tail-coverts are narrowly tipped with dull light brown ; the basal 

 portion of the tail is grey, marbled with blackish brown, the terminal third being nearly black. The 

 bird sent by Baron von Hiigel so closely resembles this specimen that I need give no description of it. 



