THE ORANO. 
309 
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 running 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 tlie nails of all the digits being flattened; the 
spinal column is nearly straight; they have fourteen pairs 
of ribs and eighteen dorso-lumbar vertebrae, there being in 
the other apes usually seventeen, as in man. The siamang 
lives in tlie forests of Sumatra; others inhabit Java, Borneo, 
Cambogia, etc. 
The orang-outang inhabits the low swampy forests of 
Sumatra and Borneo, being confined to those two islands; 
it is 1.38 metres* (4^-5 feet) high; it has twelve pairs of 
ribs, the same number as in man; the arms are very long, 
stretching 7 feet 9 inches, and reaching the ground, so that 
in walking they rest on their knuckles, swinging the body 
through their long arms as if walking on crutches; their 
posture is only partially erect. The forehead is less strongly 
marked than in the other apes, showing better the shape 
of the skull. The volume of the brain, both of the orang 
and chimpanzee, is about twenty-six or twenty-seven cubic 
inches. The following table will show, according to 
Wyman, the relative capacity of the skull in the different 
apes as compared with man: 
TJ?[e average capacity of the Caucasian skull is 91-92 cubic in. 
" " n African " 85 " 
" Australian ^ ^7 5-79 
" Gorilla —^i^"-' 29 to near 
35 cubic in. 
" Chimpanzee " 26 " 
" " Orang " 25 " 
* Wallace says that the orang of Borneo never exceeds 4 feet 
2 inches in height. Its native name is Mias, ('* The Malay Archi- 
pelago.") 
