14 TYPES OF ANIMAL LIFE 



branch to branch by their long arms, with such amazing 

 rapidity that they seem almost to fly through the forest. 

 We have often watched their wonderful motions in a 

 large cage specially provided at the Zoological Gardens. 

 We have also listened to the remarkable manlike sounds 

 they emit (as before said) when singing or shouting, as 

 they so often do. In spite of their great activity these 

 animals are exceedingly gentle and make excellent pets, 

 although they can inflict terrible wounds with their 

 elongated canine teeth. The siamang (Fig. i), which is 

 the largest of the gibbons, inhabits Sumatra, and goes 

 about in troops there, making the woods re-echo morning 

 and evening with its deafeningly sonorous cries. 



The gibbons have arms so long that they reach the 

 ground while the body is perfectly erect. This extreme 

 elongation of the arms tends to prevent our noticing the 

 really great proportional length of their legs. In nothing 

 do the gorilla, chimpanzee, and orang difier from man in 

 structure more notably than in the shortness of their 

 lower limbs. The gibbons go to an extreme the other 

 way, for if the leg be compared with the body as to its 

 length, then the gibbons have even slightly longer legs 

 than man himself. This is a very noteworthy approxi- 

 mation to human structure. There is yet another. We 

 have already said that only one monkey, a gibbon, has a 

 chin. That monkey is the just mentioned siamang. 

 Its chin is more developed than is that of not a few 

 human beings. In spite of these approximations they 

 have one noteworthy falling off behind. The body 

 is bare where it rests on the ground in a sitting posture, 

 and the hardened naked patches of skin thus situated 

 are spoken of as ischiatic callosities on account of the 

 bones (ischia) which they invest. In possessing these 

 callosities they agree with all the other monkeys of the 



