Evening star., 1937-02-13

Mans brain keeps on growing until
the age of so or go.
This is the most logical Interpretation,
says DR.. Ales Hrdlicka, curator OF
physical anthropology Of the Smith
sonian Institution, for slight put
constant increase in the dimensions OF
the head which continues throughout
most of adult life until the changes
associated with old age begin.
The increase in head size has been
found by DR.. Hrdlicka himself in meas
urements made on "old Americans
persons with at least three generations
of American ancestry-and on large
group Of Pueblo Indians. 1t has Just
been demonstrated strikingly by reported
measurements of large groups OF Rus
slams of various racial groups, and it
appears in the great body of data COL
lected by French anthropologists.
There is no evidence" DR.. Hrdlicka
says, that either the scalp or the bones
of the vault thicken with age. The en-"
largement of the head after 80 in the
males and after Is in females in breadth,
height and length precludes the possl-
bility of its being due to growth in the
frontal sinuses-for these have attained
their full growth at these ages.
This seems to leave as the cause OF
the augmentation only growth OF the
brain. Just why and how this should
continue after adult life is reached will
be point for future determination
There is no evidence that the increase
in brain size is accompanied by any
change in brain functioning. 1ntelli-
Tn pCfQhICne0
a high probability that only in excep-
tional individuals does absolute intelli-
gence increase after the first two decades
Of life. The brain growth, however,
seems to be general throughout the
human race-although there Is consld-
cradle racial and individual variation.
Among the old Americans, DR.. Hrd-
hcka found that in both men and women
the length and the breadth Of the head
increase, both absolutely and in relation
to the rest Of the stature, up to about
the middle decades Of life. With women
this is more regular than with men.
With women there is slight but
regular increase in the height OF the
head, both absolute and relative, up to
about the sixtieth year. With men he
found no appreciable growth in this
OlMenSlOn.
The growth phenomenon is best seen,
he points out, when the so-called ce-
phalic module, or average of the three
head dimensions, for various ages is
compared. The figure increases steadily
from decade to decade. The brain
growth is so slight that It is demon
strable only by the exact measurements
Of the professional anthropologi ogist-but
1t Is shown so universally that there can
be no question Of its actuality.
The growth Of the Uranium, DR..
Hrdncka finds, is accompanied by a
similar growth in the dimensions of the
face. This is partly a result of the
Uranium increase, although only in
directly. The face less the forehead, DR.
Hrdlicka says, can be viewed only as an
adjunct or associate Of the vault Of the
head, the only direct correlation between
the two being that of breadth. The
functions and origin Of the face and the
vault differ radically, the former in the
main being the product Of the apparatus
Of mastication. There Is. however, some
correlation between both and stature.
Facial proportions might be changed
somewhat by changing habits Of masti-
cation. The increased dimensions can
be found with both sexes up to middle
life. DR.. Hrdlicka says. After that, as
With the Uranium thereSs . stght -.