50 ARBOREAL MAN 



The one is characteristic of the higher, and the other of 

 the lower, living members of the Primates. The most 

 typically arboreal of the Lemurs know but little dis- 

 tinction of hand and foot; both are equally grasping- 

 suspending organs, and as a consequence it matters little 

 to the animal if it hangs or climbs head upwards or head 

 downwards. Nycticebus tardigradus positively seems to 

 y" prefer an inverted position, and I have noticed that, 

 when perfect freedom of action is permitted, the animal 

 nearly always suspends itself by its feet and hangs head 

 downwards whilst it eats. When going to rest in the 

 daytime, it will climb to the top of its cage, and then, 

 turning round, go to sleep upside down like a bat. In 

 resuming its activity towards evening, it releases the grasp 

 of its hands, and carries out a careful examination of 

 everything within its reach before it relaxes the grasp of its 

 feet. Nycticebus will also grasp food and other objects 

 with its foot, but shows nevertheless a decided preference 

 for using its hand for this purpose. This specialization 

 of the foot as a grasping organ has been carried still 

 further in the New- World monkeys, and it has conferred 

 upon that group the title Pedimana, or foot-handed, in 

 the classification of some former zoologists. In the 

 American monkeys, the development of the prehensile 

 tail and specialization of the grasping foot at the expense 

 of the grasping hand has played a very important part, 

 and to this question we will return later. The higher 

 Primates of the Old World, on the other hand, have 

 differentiated the functions of the hind and fore limbs 

 very thoroughly. They suspend themselves only by the 

 fore-limbs, and use their hind-limbs solely for passive, 

 but still grasping, support; they do not hang or climb 

 head downwards. There is a homely, but not therefore 

 necessarily unimportant, difference manifested in the 

 arboreal activity of these two extremes in Primate life. 

 A Lemur climbs up among the branches head first; 

 Nycticebus ascends with extraordinary deliberation, 



