HUMBOLDT ON THE ORGANS OF THE VOTCE. 345 



a. It 



a, Larynx of Sciurus granatemis, opened ; b, os hyoides. 



the superior larynx of these mammiferae. When the small sapajous 

 shut the epiglottis, and force, at the same time, the air into the trachea, 

 the current of air is reflected downwards, and passes into the valves 

 or pouches, the vibrations of which modulate the voice. The Simla 

 (Edipus, the Simla Jacchus of the Orinoco, the Simla leonlna, and 

 several new species of small apes, imitate the voice of the Galllnacece. 

 In them the os hyoides is slender, and presents very long cornua, 

 resembling that of man : other apes, on the contrary, particularly those 

 which have a very loud voice, and which are designated by the name of 

 howlers, have the larynx of a very complicated structure. I do not 

 think there exists a single genus of animals presenting such extra- 

 ordinary contrasts in the organ of voice, as the apes. 



The small sapajous of America have the os hyoides slender and of 

 simple construction ; the large ones, as the Simla panlscus, and a 

 species, unknown to the present time, and which we found on the 

 banks of the river Amazon, (the chuva of Bracamorros,) have an 

 osseous tambour. The same kind of tambour is also found in the 

 howlers : it seems to be wanting in the apes of the old world, of which 

 some, on the contrary, have, like the baboons and the orang-outang, 

 described by Camper, a membranous sac in which the voice becomes 

 lost. The most complicated larynx of all presented by this family is 

 that of the Simla seniculus of Jacquin, which congregate in great 

 numbers on the Anacardium caracolls, the ochroma, and the myrodla, 

 on the banks of the Magdalena. Authors often confound the Simla 

 seniculus, the capuclna, the beelzebub, and the aragnato of the Orinoco 



