f 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 through 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.

But perhaps the most absolutely distinctive character about the muscles
of the foot is the existence of what is termed the 'peronaeus 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 anatomical differences:--

1. By the arrangement of the tarsal bones.

2. By having a short flexor and a short extensor muscle of the digits.

3. By possessing the muscle termed 'peronaeus 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 alter