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, 
1.¢., the gibbon (Hylobates, 
Fig. 536); the orang (Jf- 
metes pithecus) and chim- 
panzee (If. niger, 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 pee stirs a of Siamang Ape, a gib- 
eighteen dorso-lumbar ver- 
tebree, there being in the other apes usually seventeen, as in 
man. ‘The siamang lives in the forest of Sumatra; others 
inhabit Java, Borneo, Cumbogia, etc. 
