II MAN AND APES: HAND AND FOOT 123 



of the arm, is, at the other end, continued into 

 tendons, or rounded cords, which pass into the 

 hand, and are ultimately fixed to the bones which 

 are to be moved. Thus, when the fingers are 

 bent, the fleshy parts of the flexors of the fingers, 

 placed in the arm, contract, in virtue of their 

 peculiar endowment as muscles ; and pulling the 

 tendinous cords, connecting with their ends, cause 

 them to pull down the bones of the fingers towards 

 the palm. 



Not only are the principal flexors of the fingers 

 and of the thumb long muscles, but they remain 

 quite distinct from one another throughout their 

 whole length. 



In the foot, there are also three principal flexor 

 muscles of the digits or toes, and three principal 

 extensors ; but one extensor and one flexor are 

 short muscles ; that is to say, their fleshy parts 

 are not situated in the leg (which corresponds 

 with the arm), but in the back and in the sole of 

 the foot regions which correspond with the back 

 and the palm of the hand. 



Again, the tendons of the long flexor of the toes, 

 and of the long flexor of the great toe, when they 

 reach the sole of the foot, do not remain distinct 

 from one another, as the flexors in the palm of the 

 hand do, but they become united and commingled 

 in a very curious manner while their united 

 tendons receive an accessory muscle connected 

 with the heel-bone. 



