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Three principal sets of muscles, called “ flexors,” bend the 
fingers and thumb, as in clenching the fist, and three sets, 
—the extensors—extend them, as in straightening the fingers. 
These muscles are all “long muscles;”’ that is to say, the fleshy 
part of each, lying in and being fixed to the bones 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, connected 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 ex- 
tensor 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. 
But perhaps the most absolutely distinctive character 
about the muscles of the foot is the existence of what is 
termed the peroneus 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 
