Ixx 



found the opening in the trachea, but the soft parts wei*e too 

 much injured by decomposition to admit of an accurate exa- 

 mination of the sac itself. The specimen from which the 

 following account is taken is an adult, or probably, an old 

 female. 



The cervical air-bag (fig. 1) occupies a broad and deep 

 depression on the forepart of the neck, immediately above 

 the sternum and furculum bone, which latter in this bird is 

 small and imperfect. The sac is not observable either in the 

 living or the dead bird, unless distended, when it slowly bulges 

 forwards and laterally, and fills the depression above-mentioned ; 

 it is not, however, even then so prominent as to cause any 

 remarkable deformity. On examining this region during life, 

 the sac being undistended, I found the skin very moveable ; it 

 gave to the hand the sensation of great warmth, when con- 

 trasted with the surrounding parts. The entire of the trachea 

 was very moveable to either side; but on fixing it steadily, and 

 carrying the fingers along its forepart down to the sternum, 

 the tube was felt a little above the latter to be flattened or 

 depressed, but no slit or opening could be distinguished ; the 

 sac was perfectly flaccid and compressed, and the communica- 

 tion with the trachea was closed. This examination did not 

 appear to cause any peculiar uneasiness in the part, or to 

 excite any general irritation in the respiratory system. This 

 bird, however, is very restless and timid, and very impatient 

 under any restraint ; it is also possessed of great muscular 

 power, three or four men being required to secure it, and the 

 attempt to do so is by no means free from danger, either to 

 itself or to those around, as it struggles with great violence, 

 and strikes with its powerful claws in every direction. I suc- 

 ceeded twice, however, to my satisfaction, in feeling this 

 region ; and I think I am warranted in concluding that the 

 tracheal opening is usually closed, and that it may be opened 

 at the pleasure of the animal. The plumage in this situation 

 is thin and scanty ; the feathers are chiefly of the double spe- 



