124 MAN AND THE LOWER ANIMALS n 



But perhaps the most absolutely distinctive 

 character about the muscles of the foot is the ex- 

 istence of what is termed the peronceus longus, a 

 long muscle fixed to the outer bone of the leg, and 

 sending its tendon to the outer ankle, behind and 

 below which it passes, and then crosses the foot 

 obliquely to be attached to the base of the great 

 toe. No muscle in the hand exactly corresponds 

 with this, which is eminently a foot muscle. 



To resume the foot of man is distinguished 

 from his hand by the following absolute anatomi- 

 cal differences : 



1. By the arrangement of the tarsal bones. 



2. By having a short flexor and a short ex- 



tensor muscle of the digits. 

 3. By possessing the muscle termed peronceus 



longus. 



And if we desire to ascertain whether the 

 terminal division of a limb, in other Primates, is 

 to be called a foot or a hand, it is by the presence 

 or absence of these characters that we must be 

 guided, and not by the mere proportions and 

 greater or lesser mobility of the great toe, which 

 may vary indefinitely without any fundamental 

 alteration in the structure of the foot. 



Keeping these considerations in mind, let us 

 now turn to the limbs of the Gorilla. The ter- 

 minal division of the fore limb presents no diffi- 

 culty bone for bone and muscle for muscle, are 



