THE POISE OF THE HEAD 117 



base of the skull, and in the Anthropoids they are still 

 further forward. In Man the head is practically balanced 

 upon the first cervical vertebra (see Figs. 40 and 41). 



The general factor which underlies this forward migra- 

 tion of the condyles is involved early in arboreal life, and 

 it is one that proceeds far in animals that are still purely 



Fig. 40. — Base of the Skull of a Monkey [CercopUhccm). 



arboreal. The final changes which have taken place in 

 Man might be ranked among the finishing touches of 

 human development, for they consist, not so much in 

 any further forward migration of the site of the condyles, 

 as in the culmination of that other process which we 

 have termed the recession of the snout region. In the 

 giant Anthropoids the head itself has already attained 



