THE MONKEYS AND APES. 



621 



The apes live in trees, only occasionally walking on the 

 ground ; their posture is semi-erect ; they are tailless, the 

 fore legs are much longer than the hind legs, and used as 

 arms, the radius being ca- 

 pable of complete prona- 

 tion and supination. In 

 the form of the skull, of 

 the brain with its convolu- 

 tions, and in the teeth, 

 there is a still nearer ap- 

 proach to man. 



There are three typical 

 forms or genera of apes, 

 i.e., the gibbon (Hijlobates, 

 Fig. 536) ; the orang (Mi- 

 mi'tcs pithccus) and chim- 

 panzee (J/. niyer, Fig. 

 537), and the gorilla. The 

 gibbons are nearest to the 

 monkeys; they are little 

 less than a metre (3 feet) 

 in height, and are very 

 slender, with very long 

 arms, so that they are rapid, 

 agile climbers, also run- 

 ning over the ground with 

 ease and rapidity ; when 

 standing erect the fingers 

 touch the ground ; only 

 the thumbs and great toes 

 have true nails, in all the 

 higher apes the nails of all 

 the digits being flattened ; 

 the spinal column is nearly 

 straight ; they have four- 

 teen pairs of ribs and 

 eighteen dorse-lumbar ver- 

 tebrae, there being in the other apes usually seventeen, as in 

 man. The siamang lives in the forest of Sumatra ; others 

 inhabit Java, Borneo, Cnmbogia. etc. 



Fig. 536. Skeleton of Siamang Ape, a gib- 

 bon. After Owen. 



