Evening star., 1931-12-23
FACE MUSCLES ACT
AFTER EXPERIENCE
Infant Is Fully Equipped at
Birth, but Has no
Expression.
BY T@OMAS r. HENRY.

~ nun an IlldllI lldS llO sldl
sion at birth.
1t comes into the world. however,
fully equipped with nerves and muscles
for smiling or pouting. All that is
needed is the appropriate stimuli from
experience to set them in action.
This is reported in the current year
book of the Carnegie Institution Of
Washington as a result of far-reaChing
investigations of DR.. F. Huber, research
associate, On the human mmetlc mus
culatrc-thc muscle supply in the face
which is used in expression. Dr. Huber
found that thee muscles are doVcloDed
and provided with nerve supply before
birth. but that facial expression evolves
very gradually in connection with the
completion of SenSory mechaniemS and
with the elaboration of association CEN
ters. During the first year there is
great progress in the conscious and
intelligent reactions of the infant to the
surrounding world. and cCrrcsDOndin%ly
the facial expression becomes more
manifold end definite
Served by Nerve Trunks.
There are two great nerve trunks
euDplylng the face. One, the SC-callCd
T:2cminal nerve, conveys sensation to
the brain. 1t is responsible for the dis
comfort in tOOthache or neuralgia. The
U.h~, the facial nerve, hitherto has
btt.i supposed 10 convey only motor
impulses from the brain back to the
facial muscles. One Of DR.. Hubor'S eX-
pciln rnts reported in the year book
throws a new light on this classical
Idea of the nervous system. Ii was a
painful experiment and the scientisy
himself was tn" SubiCct BY means
0f eleptrpSp ipSi,iGl,o1 Of
this facial nerve. giving definite re-
sponse of the mimctic muscles of the
forehead and checks. were heated and
marked with indelible ink. Then the
trigeminal nerve was blocked with no.
vocaln, giving complete aneStheSia. Fol-
lowing this the same facial nerve points
were again stimulated with an elCctrode
and the same muscles contracted. This
proved concluSively that the facial
nerve works b1th wayS-as a sensory
and motor conductor. Thus far,
however, DR.. Huber and his associates
have been unable to find any sensory
organs located in the superficial facial
muscles.
Study of these facial muscles in the
white and colored races revealed a note
worthy racial difference which pre-
sumably would bring about racial pat
terms of facial expression. The chief
found by an embrvological study are
formed six months before birth. This.
1t IS stated in the report. opens up an
important field for future research.
Pituitary Glands Removed.
Other noteworthy physiological studies
reported in the Carnegie year book deal
with the effect of hormOneS. the eX-
tremely powerful chemical Secretions of
tEc endocrine glands on behavior DR.
c. P. Richter and DR.. G.. B. Wislocki
renewed, either entirely or in part, the.
pituitary gland in numerous rats 1t
was found that when the whole gland
was removed the spontaneous activity
OF the animal was greatly reduced and
tne body weight and the food intake
are reduced to low level, where they
may remain fairly constant When the
gland is Cnly partially removed. how
ever, spontaneous activity is not af-
fc.tad
After removing the gland the expert
mentors uled to make up for it by
injections OF pituitary extracts The
found that in some cases tie weight
and appetite could be restored, but that
the treatment had no effect en- Spon-
taneous activity. Apparently some ac-
tlVatlng principle had been lost in the
extract Pituitary injuries have often
been associated with an abnormal de-
sire for water, Richter and WiSlocki
found however, that this was due to
INJURY of nearby part of the brain.
and that the gland itself had nothing
to do with it The water craving oc-
CURED in only one out of ten animals
IN which the pituitary was totally eX-
tlrpatcd, In each case the thymus and
lymph glands over the entire body be-
come greatly enlarged and there was
an extensive disappearance of body fat.
third Carnegie Institution research
project resulted in the localization of
TWO balance" centers in the brain
one for forward and the other for
backward balance These were both
Iound IN one lcbe OF the cerebellum
through eNperiments with catS