494 ORNITHOLOGICAL SKETCHES 
dark Aquila adalberti to be a colour-variety of Aquila im- 
perialis, and the light-coloured bird to be the immature state 
of the same species. 
I give for comparison the measurements of the eagle that 
I killed at Madrid, and of seven Slavonian Imperial Eagles. 
Length. | Breadth. | Wing. Tail. Tarsus. |Middle toe. 
cm. cm. em. cm. em. em. 
Aquila imperialis (adalberti) from the Pardo at Madrid. 
3.| 79 | 194 | 575 | 33 | 10 65 
Aquila imperialis from Slavonia. 
dg. 80° 196 62 31-2 9-2 7 
Or 286 213 08 32 8:5 8 
Efe Wh seul 203°1 60 29°8 9°5 65 
OE 82 210°5 62 2 9°5 6 
OF 82 223°5 61:5 315 10 6°5 
Giz 81:5 204-5 61:5 315 10 7 
So co 184 57 29 9-2 S39) 
