The Intermountain Catholic. (Salt Lake City [Utah] ;) 1899-1920, 1908-08-01
Facts You Didn't Know About Your
Fingers.

Facts You Didn't Know About Your
Fingers.
There Is very ancient belief that a
Dlood 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 wedding
ring. In literature allusion to it is made
as the "vena amoris," or loves vein.
Unlike most notions of the kind, this
IDEA is entirely correct, for a vein does
arise directly at the root of the ring
nnger and, running over the back of
the hand, finds its way through the
royaP' vein, the Auxiliary" the Sub
clavian' and the. 'Tnnominate" 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 probably
quite different. It's use for the purpose
goes back to prehistoric times, and it's
selection is likely to have been due to
the fact that it is the least free in it's
movements Of all the fingers. Accord
lngly, a ring encirclng it will interfere
less with the use of the hand than if
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 movements of
the ring finger considerably Anybody
may test this for himself by holding
the third and fifth fingers forcibIy bent
and trying at the same time to extend
the ring finger
The native Australian, who repre-
sents very degraded and primitive
human type, has a 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 it
Velopment of a member to which man
seems TO represent a stage in the de-
is mainly indebted for his progress. It
is the "opposable" thumb, which passes
over and across the palm, that makes
the hand an efficient instrument.
The great apes, such as the gorilla,
the chimpanzee and the orang-outang,
more especially the two former, have
fairly developed thumbs; but relatively
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 a tool has come about the
slow human advance which finds its ul-
Innate triumph today in what we call
civilization. AS the hand gained great
er efficiency the brain grew, for what
ever 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 grew together, the instru-
ment and the directing intelligence act
ing and developing co-ordinately.
fnrr laI
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 hui
man thumbs, nor any parts of the
hands of every peoples. such as the
cave dwellers of early southern France,
have been preserved. The bones of
those members, being small, have dis
appeared-more's the pity, inasmuch as
a study of them would be vastly in
structive
In the higher races of mankind the
upper bone of the arm is twisted in a |
peculiar way, so as TO make the hand |
a better tool by bringing the thumb |
into more favorable position. This is
one of the most curious of natures an
atomicai adaptations. Furthermore, !
the muscles of the thumb are so ar
alASN0 6-S W SANC " Olldt 1llClllbSA IlOIS
action than is enjoyed by |
any of the other fingers. There is a |
1exor and an extensor for each joint, !
which is not the case with the other
fingers, and the thumb muscles are ex-
strong.
The real wrist, as one might say, is |
he elbow joint. 1t is all hand, practi-
ally speaking, from that point to the |
fps of the fingers. When you turn your
wrist, 1t is the whole forearm that
makes the twist; and every movement
If the fingers is controlled by the mus
lies of the forearm.
The power 10 turn the wrist to and
70 at the elbow joint is possessed only
~ human beings and monkeys, and
wen the higher apes are not able to
10 the trick nearly as well as we can.
n this movement the great "biceps"
muscle in the upper arm is Importantly
its powerful action in turn
ng the forearm outward being ac-
for the fact that we are able
o put so much more strength into
visit in that direction than the oppo-
lite way. Many of our most familiar
ools, indeed, such, as the screwdriver,
ire made with reference to the an
tomical popularity in question. 1t is
or this reason, and no other, that all II
screws turn to the right.
In conclusion, mention may be made
# the rather curious fact that the
zones of the arm are arranged primar-
ly for the purpose of carrying the
land to the mouth-food being, of
curse, the first necessity of life. If
-ou do not believe it, try 1t for your
elf and see how much more naturally,
Vhen your arm is bent, your hand
moves in that direction than in any
Their.
uLArA.n MAJ EIinihIa