Evening star., 1936-12-28
Scientist Reports on Forces
Governing Facial Appearance
Effect of Bone Gr0,Uth in Brains, Eyes
and Legs Described by Head of
Dental School at HARVARD.
BY THOMAS r. HENRY.

BY THOMAS r. HENRY.
ATLANTIC CITY, December 49,
The effect Of growing jawbones and
rudiments of teeth in brains, eyes
and legs was reported to the American
Association for the Advancement Of
Science here today by DR.. Lawrence
w. Baker Of the Harvard University
Dental School.
The ultimate purpose Of the investi-
cation is to find out the fundamental
forces responsible for the shape and
appearance Of the face.
The lower jaws Of unborn rats
were implanted In the tissue Of mature
animals In an effort to separate the
inherent and functional influences
which operate in the growth Of teeth.
At the same time, he fed rats with
minute amounts Of madder, . red
dye which Is carried by the blood
stream and has q special affinity for
growing bone. The red staining Of the
transplanted bones when the expert
mental animals were killed weeks later
showed DR.. Baker Just what sort of
growth process had taken place.
Never before" he said, has the
riddle of growing bone been investi-
gated in such an intimate manner"
Explains Development.
In the development Of jaws and
teeth of any individual, DR.. Baker
explained, two factors are balancing
or pulling against each other. One is
the inherent urge of the basic sub
stance to become a jaw or a tooth Of
certain shape or size. This is laid
down in the germ plasm Of the in
dividual. The other Is the constant
pulling or pushing Of the other de-
veloping organs associated with Jaw
and teeth, such as the muscles of
mastication. These iateract upon each
other in an extremely complex fashion.
Thus, DR.. Baker explained, there
probably is some mysterious element
in the growth and eruptive forces of
the teeth which determine largely the
shape Of an individuals face. He
showed pictures Of dog. all of whose
teeth on one side were pulled in early
puppyhood. Practically every bone in
the animals head varied strikingly
from the normal as it grew to ma
turity until it was a weird caricature
Of a dog.
Something in the teeth themselves
governed the growth of the creatures
face bones, he demonstrated, rather
than a disbalance set up by lack of
exercise on that side, because when
the teeth were left intact and all the
muscles attached to the jaws on that
side were paralyzed no such bone de-
formity resulted. Moreover, he said,
1t often has been noted that while
an infants teeth are eruptipg the
face bones are growing faster than
any other bones in the head and the
face is taking on the shape it will
have for life.
Transplanting Experiments.
It is in an effort to throw some
light on these mysterious Influences"
that the transplanting experiments
have been attempted at Harvard. BY
placing teeth and jawbones in entirely
strange environments, where none of
the customary environmental forces
to which they are subjected are pres
ent, it Is hoped to find out just what
they are inherently compelled to do,
by forces within themselves alone.
The best growth has been obtained
in leg muscle. Muscle Is the normal
matrix in which teeth and jawbones
grow. DR.. Davis has kept jawbone
growing in Q rats leg for 40 days.
It took on the same shape Is q nor
NAL jawbone Of rat 40 days old, but
its growth was far less pronounced.
The growth was much less pronounced
in the eye and in the brain-tissue
surroundings which were not made
for jaws and teeth.
The transplanting into the brain,
however, may have uncovered an i'm
portant fact in brain physiology. It
has been observed that when certain
biological stains are placed in the
circulatory system of an animal
trypan blue is a notable example
practically every organ of the body
becomes deeply stained except the
brain tissue. This has led to the
belief that there is some mysterious
barrier in the blood vessels of the
brain which protects this organ
against the entrance Of foreign sub
stances. Nobody can ever get a blue
brain or green brain.
p11t tho 10 uy1novo ryrau, 10, %ka
tissue and its growth additions were
red, due to their affinity for madder.
This dye must have Travelled right
into the brain through the blood
stream, thus finally disposing Of the
long-held brain barrier hypothesis so
far as the circulation Is concerned.
DR.. Baker also was able to trace the
source from which the growing bone
IN the brain obtained its blood supply.
Strange Insect Family.
A strange family Of insects, whose
males can survive only by eating their
sisters, was described at q group
meeting Of the association by DR..
Stanley E. Flanders, entomologist Of
the University Of California.
What may be considered the wierd-
est family arrangement in creation
Is OF considerable economic tmpor-
tance, he said, for these particular
insects happen to be parasites Of scale
insects, which are very injurious to
orange trees. Only by understanding
their way Of life can the benefactors
be kept alive in this country,
First, Dr.. Flanders said, the female
OF this minute, wasplike creature Ill
troduoed from South Africa, bores
into the scale insect and lays her
eggs. The females emerge from the
eggs first into the blood stream of
the doomed host. They proceed to
drink all the blood and eat all the