THE CHARACTERS OF HOMO 437 



(_/) The muscles of the thumb are better developed, 

 giving free play to that member, and the index 

 finger is freely movable independently of the 

 others. 



(k) The bones of the lower arm (radius and ulna) are 

 so constructed that the arm may be rotated, 

 as in turning a screw. This is of the utmost 

 importance in connection with the use of tools. 



(/) The leg and foot are adapted for walking, and the 

 whole surface, from the ends of the phalanges 

 to the base of the tarsus, is applied to the 

 ground. 



(m) The great toe is not freely movable, and is no 

 longer readily used for grasping. 



Other characters may be described as negative, being 

 due to the loss of parts or functions : 



(n) The tail is lost, being represented only by the 

 coccygeal bones beneath the skin. This is, of 

 course, not peculiar to man. 



(o) The greater part of the hair has been lost from the 

 body. 



(p) Certain muscles of the head and neck have ceased 

 to function, at least normally. Such are those 

 which move the ear, and that which wrinkles 

 the posterior part of the scalp. Some people, 

 however, can use these muscles. 



(<?) The point of the ear is lost, being represented only 

 by a small tubercle. On the other hand, the 

 lobule has developed. 



(r) There exists in the throat a small sinus or space 

 which appears to represent the vestige of a 

 howling sac, such as is so well developed in 

 certain South American monkeys. The sac 

 disappeared long before college yells were in- 



