The Detroit times. [volume] (Detroit, Mich.) 1903-1920, 1908-07-24
SHOE REPAIRING.
Facts You Didn't Know About Your Fingers


There Is very ancient belief that
blood vessel extends from the base
OF the fourth finger OF the left hand
TO the heart. whence as Is alleged
the choice OF that finger for the we'd
ding ring. In literature allusion TO 1t Is
made as the "vena amoris,' or loves
vein. Unlike most notions of the
kind. this idea Is entirely correct, for
vein does arise directly at the root
Of the ring finger and, running over
the back Of the hand, finds its way
through the royal vein. the 'axil-
larry" the "subclavian and the I'm
nominate" to the heart. This vessel
Is very conspicuous. standing out
clearly when the hand hangs Imply
downward.
The reason for putting the ring on
the fourth finger, however, is prob
ably quite different. Its use for the
purpose goes back to prehistoric times,
and its selection is likely to have been
due to the fact that 1t Is the least free
In its movements Of all the fingers
Accordingly, ring encircling 1t Will
interfere less with the use Of the hand
than IL placed on any other digit.
1t happens that the extensor tendon
Of the fourth finger is attached to
those Of the third and fifth fingers by
cross-bands which restrict the move
ments Of the ring finger considerably.
Anybody may test this for himself by
holding the third and fifth fingers for
chilly bent and trying at the same time
to extend the ring finger.
The native Australian, who repre-
sents a very degraded and primitive
human type, has thumb that Is set
very far back on the hand, so as to
look somewhat like the toe-thumb OF
an anthropoid ape. This, OF course,
is particularly interesting, because 1t
seems to represent stage In the de-
velopment OF a member to which man
Is mainly indebted for his progress.
1t Is the "opposable" thumb. which
passes over and across the palm, that
makes the hand an efficient instru-
ment.
The great apes, such as the gorilla,
the chimpanzee and the orang-outang.
more especially the two former, have
fairly developed thumbs; but relative
ly to the size of the hand, they are
much smaller than ours, and they are
not "opposable." While good enough
for trapeze work among the trees they
are poor tools for handling things.
With the gradual development Of
the thumb as tool has come about
the slow human advance which finds
its ultimate triumph today in what we
call civilization. AS the hand gained
greater efficiency the brain grew, for
whatever the hand was able to achieve
had Its reflex In the mind. Thus, 1t
may be said that the human thumb
and the human brain together, the in
strument and the directing intelligence
acting and developing co-ordinately.
Save for the examples afforded by
primitive races, such as the Australian
blacks, we have no typical thumbs,
later than those OF the apes. TO com
pare with our own. No prehistoric
human thumbs, nor any parts OF the
hands Of very peoples. such as the
cave-dwellers of early southern
France, have been preserved. The
bones Of those members, being smaA
have disappeared-mores the pity, in
asmuch as a study OF them would be
vastly instructive.
In the higher races OF mankind the
upper bone OF the arm Is twisted In Z
peculiar way, SO as to make the hand
better tool by bringing the thumb
into a more favorable position. This
is one Of the most curious OF Nature
anatomical adaptations. Furthermore
the muscles OF the thumb are so ar
ranged as TO give TO that member
more independent action than Is en-
joyed by any OF the other fingers
There is flexor and an extensor for
each joint, which Is not the case with
the other fingers, and the, thumb mus
cles are extraordinarily strong "a
| The real wrist. as one might say, Is
the elbow joint II is all hand. practi
cally speaking from that point 10 the
tips OF the fingers. When you turn
your wrist, II Is the whole forearm
that makes the twist; and every move
ment OF the fingers is controlled by
the muscles OF the forearm.
The power TO turn the wrist TO and
fro at the elbow joint Is possessed only
BY human beings and monkeys. and
even the higher apes are not able &c
do the trick nearly as well as we can
In this movement the great "bfceps'
muscle In the upper arm is important
ly concerned its powerful action In
turning the forearm outward being &C
countable for the fact that we are able