344 HUMBOLDT ON THE ORGANS OF THE VOICE. 



the human voice ; while others, the Amazons for instance, which are 

 marked with red on the bend (Jbuefy of the wing, talk so well. I 

 think I have discovered the solution of this interesting problem in the 

 formation of the os hyoides of the Psittacus. In those parrots which 

 talk, this bone is slender and prolonged at the point ; in the Aras, on 

 the contrary, who are the dullest, though ornamented with the finest 

 colours, the os hyoides presents an extraordinary shape. The interval 

 between the two cornua is partly filled with an osseous membrane, 

 which becomes narrowed towards the point and apex, and is fixed to a 

 square bone, which is more than a quarter of an inch broad. It is this 



Os hyoides, upper larynx, and part of trachea, in Psittacus araurana. 



extraordinary member, this spatula-shaped bone which, going to the 

 tip of the tongue, renders it so inflexible in the Psittacus ararauna 

 and the macaw. 



Having lived for several years almost constantly in the open air, and 

 in the midst of exotic animals, I have often been astonished at the 

 perfection with which some mammiferae imitate the voice of birds, as is 

 the case with some squirrels and small sapajous. In opening the 

 larynx of these animals I have been struck with the similarity they 

 present, with what M. Cuvier has discovered in the inferior larynx of 

 birds. If the organ of the voice of the Pelecanus olivaceus, in my 

 design, be compared with that of the Simla (Edipus of Brisson, and 

 with that of the squirrel of Carthagena, which is very different from 

 the Sciurus flavus, somewhat approaching the Sciurus erythceus of 

 Pallas, it will be seen that the larynx of the small whistling ape 

 might be mistaken for that of the orange squirrel, and similar 

 pouches which the bird has in its inferior larynx, will be found in 



