152 THE NATURAL HISTOET OF 



The face is naked, and of a bluish-black. In the 

 male, the cheeks and a superciliary band are of a 

 yellowish-white, beautifully contrasting with the clear 

 chocolate-brown of the upper half of the body ; these 

 marks are wanting in the female represented on 

 our plate. The lower extremities are of the same dark 

 colour, and the lower part of the back, and fore part 

 of the thighs, are of a yellowish-brown. The shade of 

 the colour, of both the dark and light parts, however, 

 vary considerably according to age, and the light parts 

 above, sometimes occupy a greater or lesser space. The 

 hair in healthy animals is clear and fine, except upoix 

 the neck, where it becomes lengthened, and some- 

 what woolly or curled. The young are always 

 much paler in colour than the adults, or those at an 

 advanced age, and the very young animals are of a 

 uniform yellowish-white. The general height scarcely 

 exceeds two feet seven or eight inches, and the arms 

 reach the ground when the animal stands erect. 



They are endowed with surprising agility,, and 

 their light form and slender-looking extremities 

 hardly give an idea of the great muscularity which 

 they must possess. If the extreme tree on the borders 

 of a forest can be reached by them, it will be in vain 

 to pursue farther; they swing, leap, and, as it were, 

 throw themselves from one tree to another, clearing 

 at tunes a space of forty feet, with a rapidity 

 which defies any pedestrian pursuer. When a 

 slender branch can be grasped, the body is swung 1 



