H^LOBATES HOOLOCK, THE GIBBON 409 



never leave the forest and are distributed for the most part throughout 

 southern Asia and the adjaeent islands. A lew species venture from the 

 inland jungles to the vicinity of the coast. 



Courtesy, American Museum of Natural History 



FIGS. 191 AND 192. HAND AND FOOT OF HYLOBATES SYNDACTVLUS. 



Left. Dorsum of hand showing long, slender fingers, well-developed finger-nails, a hand adapted to grasping 



the branches in the gibbon's brachiating type of locomotion. 

 Right. Dorsum of foot showing marked hand-like characters in adaptation to brachiating locomotion. The 



long, powerful, opposable great toe is specialized for grasping purposes, cooperating in this function 



especially with the syndactylic second and third toes. 



THE HOOLOCK GIBBON 



In general, the typical hue of the hoolock is black, although many 

 varieties are found, as far as coloring is concerned. The hoolocks, however, 

 are most consistent in this regard. Such variations in color as do occur 

 affect the female more than the male. The hoolock gibbon is confined in its 

 range to a limited district bounded by the Brahmaputra and Irawadi 

 Rivers. It has a distinct aversion to water and cannot swim, a fact which 



