I THE GIBBONS 39 



voice possessed by these animals. According to 

 the writer whom I have just cited, in one of them, 

 the Siamang, " the voice is grave and penetrating, 

 resembling the sounds g5ek, g5ek, goek, goek, 

 goek ha ha ha ha haaaaa, and may easily be heard 

 at a distance of half a league/' While the cry is 

 being uttered, the great membranous bag under 

 the throat which communicates with the organ of 

 voice, the so-called "laryngeal sac/' becomes greatly 

 distended, diminishing again when the creature 

 relapses into silence. 



M. Duvaucel, likewise, affirms that the cry of the 

 Siamang may be heard for miles making the 

 woods ring again. So Mr. Martin 1 describes the 

 cry of the agile Gibbon as " overpowering and 

 deafening " in a room, and " from its strength, well 

 calculated for resounding through the vast forests/' 

 Mr. Waterhouse, an accomplished musician as well 

 as zoologist, says, " The Gibbon's voice is certainly 

 much more powerful than that of any singer I ever 

 heard." And yet it is to be recollected that this 

 animal is not half the height of, and far less bulky 

 in proportion than, a man. 



There is good testimony that various species 

 of Gibbon readily take to the erect posture. Mr. 

 George Bennett, 2 a very excellent observer, in de- 

 scribing the habits of a male Hylobates syndactylus 

 which remained for some time in his possession, 



1 Man and Monlcies % p. 423. 



2 Wanderings in New South Wales, vol. ii. chap. viii. 1834. 



