small, but not unlike those of man. The nose is quite flat, the mouth is large and ugly, from the thick lips. The jaws are extremely powerful, and the canine teeth prominent. The breast is thinly haired, and the face, the fingers, palms, and soles, are naked. The back and top of the head are thickly haired, and on the side of the jaws the hair descends
![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/00/PSM_V13_D453_Head_of_orangutan.jpg/300px-PSM_V13_D453_Head_of_orangutan.jpg)
Fig. 5.—Head of Orang-outang.
like a beard. In color the hair is a dark, rusty red, sometimes brownish on the back, the fringing hair of the face usually lighter than the rest. The color of the skin is bluish-gray. The old males may be distinguished by their longer beards, which are wanting in the young, and by a peculiar swelling of the cheek from the eyes to the ears, which makes their aspect more repulsive.
The orang-outang was certainly known to the ancients, and Pliny gives an account of this species which has been extensively copied. One peculiarity, only recently observed, is that the skull undergoes a greater change in shape than usual during growth. The heads of baby-orangs bear a close resemblance to those of infants; but afterward the lower portion of the face increases rapidly in size, and the aspect of the adult is more repulsive and animal-like than the chimpanzee. Wallace says they frequent swampy localities in Sumatra and Borneo, and visit the orchards of the Dyaks for the purpose of devouring the fruit. They build nests in the trees, of boughs, in which they sleep. They climb with great ease, and traverse the forest from tree to tree in a semi-erect position, assisted by their long arms, and are capable of progressing at the rate of eight or nine miles an hour without any appearance of hurry or fatigue, going as fast as a man on the ground beneath them can run.