Evening star., 1936-11-03
STARS, MEN AND ATOMS
Notebook of Science Progress in Field,
Laboratory and Study.
BY THOMAS r. HENRI Y.

of the oran cortex. He studied 35 brains
of these apes, from animals OF both
sexes and various ages. Primate brain
studies in the past have been made on
two or three specimens OF each species,
with the result that individual differ
ences, constituting one Of the most sig
nificant factors in physical evolution,
have remained hidden.
The orang-utan is the least man
like" of the three big anthropoidS. 1t
looks least like a human being and
normally its behavior is much less "hu-
man'-although it probably was the
original wild man of Borneo."
DR.. Connolly found, as have other
biologists, that the orang -utan brain
diverged markedly from those of the
other two apes in pattern. First, it has
high frontal lobes, relative to the brains
of its fellow anthropoids. The oran is
the high brow" of the apes, rating in
this respect below man alone. This is
compensated for, however, by lack of
mass in other parts of the brain.
1t long was thought that the human
frontal lobe was the chief seat of the
reasoning faculty, for it is here that the
human brain shows its greatest diver
thesis, however, no longer is maintained
by neurologists, although it still is COM
monty held that the frontal region is
an important association area. The ex-
ceptional development OF the front part
of the oranS brain in itself might have
little significance, except as fixed char
acter of the species.
Close study of the 35 orang brains
showed, as was to have been expected,
that the principle sulci were present in
all from birth and that certain standard
ones developed during the lives of the
individuals. They are characteristic of
the orang brain, just as very similar pat
terms are characteristic OF the gorilla,
chimpanzee and human brains. But
aside from these there are minor sulci
which differ from brain to brain and the
orang seems to have more individual
variability in the pattern of these Sec
ondary channels than does the corteX of
either of the other apes
Now, generally speaking, the sulci
divide functional areas of the corteX.
This is well established, at least, for the
principal fissures-Such as the prominent
central Sulcus which divides the senSory
from the motor area, and the fiSSure of
SylViuS, the most prominent LANDMARK
of the brain, which forms one border of
the temporal lobe. the brain center for
hearing. So little is known as to the
specific functions of the smaller cortical
areas that this cannot be stated posi-
lively for the smaller depressionS.
But, whatever their purpose, the fact
of considerable individual variability in
this particular genus may be taken to
mean that the orang brain has not quite
found itself. 1t still is somewhat plastic
in the mold, representing a stage
through which the brains of other men,
bers of the group may have passed
millions of years ago. The orang brain
is, it is possible, not quite so specialized
and have further, although slight, posi-
bilities of development.
This finding is not to be interpreted,
DR.. Connolly stresses, as evidence of any
ancestral connection between the orang
and the higher apes or man. The three
apes are members of collateral lines
which have followed about the same
roads-and the orang still has a little
way to go.