iS6 Lloyd's natural history. 



than half the length of the spine, and the foot is slightly under 

 half its length. The Gibbons have two pairs of ribs more than 

 Man. The ends of the ischial bones are much everted to 

 support the callosities. 



With regard to the brain, this genus is remarkable for the 

 great reduction of the occipital lobes of the cerebrum. 



The tongue is very similar to that in Man, but it is furnished 

 with a sub-lingual process Hke that already described among 

 some of the Lemuroids. The Gibbons (except the Siamang) 

 have no laryngeal sacs The stomach closely resembles the 

 human organ. 



The Gibbons are very delicate, and rarely live long in con- 

 finement, even in their own country. They are in general 

 highly intelligent, very gentle, and become most affectionate 

 and engaging animals if kindly treated. They are, however, 

 occasionally irascible and ill-tempered, especially when adult. 



Their feats of climbing and leaping are almost proverbial. 

 It would be impossible to excel them as acrobats. When 

 walking on the ground they assume the erect posture, putting 

 the soles of their feet to the ground, separating the thumb and 

 the great-toe widely from the neighbouring digits. 



" They walk erect, with a waddling or unsteady gait, but at 

 a quick pace; the equilibrium of the body requiring to be 

 kept up, either by touching the ground with the knuckles, first 

 on one side then on the other, or by uplifting the arm so 

 as to poise it. As with the Chimpanzee, the whole of the 

 narrow, long sole of the foot is placed upon the ground at 

 once and raised at once, without any elasticity of step." 

 (Margin.) 



Their voice is very powerful and can be heard at a great 

 distance, especially when they are howling in chorus. The 



