72 ARBOREAL MAN 



times even to the extent of suppressing the development 

 of the thumb. Some have also called in the tail to assist 

 in the foot grasp, and further deprived the hand and 

 thumb of their function of suspending the body in 

 climbing. 



We see in this feature a correlated adaptation to the 

 climbing habit to which I have previously drawn atten- 

 tion; those Primates which show a tendency to depend 

 on foot grasp descend a tree head foremost, and those 

 which depend upon hand grasp walk down feet first. 

 The human stock walked down, and converted the oppo- 

 sable big toe into a remarkably useful supporting big toe. 



The human thumb is an arboreal grasping organ, per- 

 fected' by ancestors which depended upon their hand 

 grasp in their arboreal activities. The human big toe 

 is nothing more than a modified arboreal grasping organ, 

 the primitive characters of which were stamped upon it 

 by its specialization as a grasping organ, which supported 

 the weight of the body in climbing. 



We must not overlook the fact that although the 

 grasping power of the big toe is largely lost in modern 

 Europeans, it must still be reckoned as a distinctly human 

 possession. Kohlbrugge has remarked that one would 

 hardly dare to suggest that the presence of a prehensile 

 big toe was a sign of human inferiority, were the discus- 

 sion to take place at an anthropological congress held in 

 Tokio. In the very primitive negrito races the power of 

 foot grasp is well retained. For the purposes of petty 

 theft the Sakai largely relies on the grasp of his toes (Skeat 

 and Blagden) ; and very many other instances could be 

 furnished from races far more highly placed in the human 

 scale. 



