130 CLASS AVES. 



Both sexes have elongated feathers, which form a tuft upon 

 the head 



The total length of the adult bird is from twenty to twen- 

 ty-one inches. The naked skin of the eyes which com- 

 municates with the cere of the bill is of a livid purple, 

 becoming coloured with red according as the bird is agitated. 



The peculiar conformation of the trachea of this bird was 

 first noticed by Pere Feuille, subsequently by Messrs. Sonnini 

 and Bajon, and afterwards by M. de Humboldt. The tube of 

 this trachea, composed of alternate rings, like those of the 

 guan and the raarail, does not differ from that of the first, bvit 

 by its greater length, and by the sinuosity which it describes. 

 It has no peculiar muscle, as in the marail. 



The trachea, in passing over the left clavicle, rises over the 

 great pectoral muscle along the crest of the sternum, directs 

 itself the entire length of this muscle as far as over the mem- 

 branous tunic which contains the entrails, turns there, and 

 reascends in the same direction over the right pectoral 

 muscle, to enter the cavity of the thorax in passing over the 

 right clavicle. The two tubes adhere to the pectoral muscle 

 by a cellular tissue, the fibres of which pass over the crest of 

 the sternum. 



INI. de Humboldt, who has measured the tube of this 

 trachea, says that that of the male, from the upper larynx to 

 the bronchiae, was fifteen inches seven lines, while that of the 

 female was but five inches four lines. The trachea of the 

 male descends at first between the integuments beyond the 

 sternum, as far as the legs, then it turns, makes a great 

 sinuosity in reascending, and enters between the lungs. The 

 trachea of the female, wliich is shorter, in the proportion of 

 five to two, does not make this sinuosity, but enters, Avithout 

 refolding, directly into the bronchiae. 



M. de Humboldt did not find any sacs in the lower 

 larynx of this bird, as in fact there are none in any gallina, 



