102 CLASS AVES. • 



sinuosities. The curassow of Guiana, says Sonnini, and the 

 same may be said of all the species of curassow and pauxi, 

 also utters a sort of dull humming sound, which is not a cry, 

 but a sort of concentrated sound, similar to that produced 

 from a bass-viol ; this sort of noise, which is also peculiar to 

 the turkey, seems to be formed in the cavity of the abdo- 

 men, and to escape, externally, through the pores of the flesh 

 and integuments, — so that we might almost pronounce these 

 birds to be ventriloquists. The different sounds produced 

 by the pauxis, the curassows, and by the species of penelope, 

 are modified by the sinuosities which the tube of the trachea 

 describes, and these sinuosities vary very sensibly in the 

 different species. M. Temminck has dissected a number of 

 these birds, so as by that means to satisfy himself of the dis- 

 parities which exist between each species and the rest. Many 

 of his observations in this way are new, and many of them go 

 to verify what had been already ascertained on this subject 

 by M. Bajon, in his account of Cayenne, and by Dr. Latham, 

 in the Transactions of the Linnaean Society. 



In these three genera of birds, peculiar to the southern por- 

 tions of the new Continent, are found, in the tube of the 

 trachea, sinuosities, of greater or less length. It is in this 

 strongly marked character that this trachea differs from that 

 of other gallinaceous birds ; as in these last, the lower 

 larynx of the genera of which we are speaking is destitute of 

 the proper muscles, which act as motores to this part in many 

 other genera of birds. The lower larynx and the bronchiae of 

 the pauxis, the curassows, and penelope, do not differ from 

 those same parts in peacocks, cocks, and pheasants, but in 

 the position of the rings, the distance of the membranes be- 

 tween each of these, and a small difference in the form of the 

 transverse bones from which the bronchiae depend. 



In the crax pauxi, and in all the penelopes in which the 

 form of the trachea has been observed, it has been found to 



