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MANUAL OF ZOOLOGY. 



peculiarity, and not as having any connection with the nature 

 of the food. 



In this tribe are the Gibbons (Hylobates\ the Orang-outang 

 (Simla satyrus], the Chimpanzee, and the Gorilla. 



The Gibbons form the genus Hylobates, and they belong to 

 southern Asia and the Indian Archipelago. The anterior limbs 

 are extremely long, and the hands nearly or quite reach the 

 ground when the animal stands in an erect posture. There is 

 no tail, but there are natal callosities. The body is covered 

 with a thick fur. One of the best known of the Gibbons is 

 the Siamang (Hylobates syndactylus\ which has been sometimes 

 regarded as making a nearer approach to man than any other 

 of the Monkeys. It is a native of Sumatra. It is the largest 

 of the Gibbons, and derives its specific name from the fact 

 that the index and middle toes of the hind-foot are united to 

 one another by skin as far as the nail joint. Another well- 

 known species is the common Gibbon (.H. lar\ 



Fig. 271. A, Skull of the Orang-outang. B, Skull of an adult European. 



In the Orang or " Mias " (Simla satyrus] there are neither 

 cheek-pouches nor natal callosities, and the hips are covered 

 with hair. As in the Gibbons, the arms are excessively long, 

 reaching considerably below the knee when the animal stands 

 in an erect posture. The hind-legs are very short, and there 

 is no tail. When full grown the Orang stands about four feet 

 high. It never progresses with the help of a stick, or walks 

 erect at all, except along the branches of trees, supporting itself 

 by a higher branch, or when attacked. When young, the head 

 of the Orang is not very different from that of an average 

 European child ; but, as the animal grows, the facial bones 



