44 ANTHROPOID APES. 



I have not observed eyebrows on the animals I have 

 seen, but they may occur, and the eyelashes are 

 fully developed. 



The hair is of a reddish brown colour, something 

 like burnt sienna, and the hair-tips on the back 

 parts of the body are generally brown. In some 

 individuals the hair is darker, of a russet or blackish 

 •brown ; in others it is lighter, and in the latter case 

 the breast and belly are of a yellowish white. The 

 beard is sometimes dark yellow. Some individuals 

 almost devoid of hair have been observed. 



The gilibons, or long-armed apes (Hijlobates), con- 

 stitute the fourth group of anthropoids. Many 

 kinds of this group are known, and I feel bound to 

 describe, at any rate, a few of them, in order to be able 

 to give an idea of their structure. With respect to 

 these animals, I cannot only rely on the materials 

 which are accessible to me, but must also make use 

 of the descriptions given by others.* 



The gibbons have as a rule very long arms, reach- 

 ing to their ankles when they stand upright. The 

 face is not very prognathous, the crown of the head 

 is rounded off, and the nails are flat. There are 

 small callosities on their posteriors, which are absent 

 in the gorilla, the chimpanzee, and the orang-utan. 



The largest species of these animals, which inhabit 

 part of the continent and of the islands of Asia, is 



• While writing these words I obtained a dried specimen, Sylo- 

 bates lenciscus (Kuhl), injected with Wickersheiner's fluid; a large 

 Hylohates of the same species, preserved in spirits of wine ; another 

 Hylohates alhimanus (Is. Geofifr. Saiut-Hilaire), preserved in the 

 same way; and the skeletons of Hylohates syndouitylus (F. 

 Cavier), and of Hylohates agilis. 



