Science. 
3*9 
LETTERS TO THE EDITOR. 
[ The Editor does not hold himself responsible for opinions expressed 
by his correspondents. No notice is taken of anonymous communi- 
cations .] 
To the Editor of Science : 
I was much pleased to see, by an abstract in “Sci- 
ence,” that the opportunity which Philadelphia sci- 
entists had of examining into the anatomical pecul- 
iarities of the Orang-Outang was utilized, and that 
the body of the anthropoid, deceased in the Phila- 
delphia Zoological Gardens, tell into the hands of as zeal- 
ous an anatomist as Dr. Chapman. I have since had 
access to the original paper*, and would provisionally 
offer a few comments upon such statements as Dr. 
Chapman makes with reference to the cerebral relations 
of his anthropoid specimen. 
It is stated that the brain of this Orang resembles that 
of a man more, as regards its general contour, than that 
of either of the Chimpanzees which the Dr. examined. 
It must be borne in mind that the internal dimensions of 
the cranial cavity of both anthropoid species show a 
relative excess of the transverse diameter as compared 
with the average mesocephalic human skull. But the 
correlated greater breadth of the brain is not due to a 
general greater breadth of all the lobes, for it is mainly 
provided for by the immense reduction in mass, and in 
every dimension of the frontal lobe. If the frontal lobe 
were relatively as well developed in the anthropoid apes 
as in man, the general contour of the cerebral hemi- 
spheres would be nearly the same in all three species, 
but more human in the Chimpanzee than in the Orang. 
Many of the inferences of the writer regarding contours 
and relations, seem to be based on the hardened and 
otherwise manipulated specimen, and for reasons which 
I shall advance are probably faulty. It is further stated, 
that the fissure of Sylvius runs up and down, “the post- 
erior branch pursuing only a slightly backward direction. ” 
On looking at the accompanying plate (PI. xvii, Fig. i.),f I 
perceive the reason for this statement. The Doctor’s 
specimen had been allowed, evidently, to flatten’out on its 
base, for the lower contour of the frontal and temporal 
lobes as well as of the cerebellum is an accurate straight 
line. Under such circumstances the fissures must change 
their natural direction. In both hemispheres of my Orang, 
the inclination of the Sylvian fissure (horizontal branch) 
is thirty degrees towards the ideal hemispheral axis. It 
is owing to the same imperfect manipulation that the 
author has arrived at the conclusion that the central 
fissure (Rolando’s) is more forward in the Orang than in 
the other anthropoid. According to some recent writers J 
on the convolutions, the acuteness of the angle formed j 
by the central fissure and the median fissure separating 
the hemispheres, forward is an index of cerebral develop- j 
ment. It is acuter in both my Chimpanzee brains, then 
in the Orang in my possession or in any of those figured 
in plates. 
I find the temporal lobe in my Orang well convoluted, 
showing the same sulci and in about the same degree of 
complexity as other anthropoid brains. 
Dr. Chapman’s figures give but a poor idea of the rich- 
ness in gyri and the proportions of the different parts of 
the Orang’s brain, at least as these are observable in the 
specimen which I demonstrated before the New York 
Academy of Sciences. In figure 2 § the frontal lobes are 
* On the structure of the Orang-Outang by Henry C. Chapman, M. D. 
Proceedings of the Academy of Natural Sciences of Philadelphia, x88o, 
p. 160. 
f See page 326 of this Journal, Fig. 2. 
X Meynert Archiv fur Psychiatrie VII. Clevenger. “The sulcus of 
Rolando an indication of intelligence” Journal of Nervous and Mental 
Diseases , 1880. 
§ See page 326 of this Journal, Fig. 1. 
too broad and too long, and the ethmoidal prolongation 
( Sieb-bein-scJmabel) is not indicated anywhere. Some of 
the sulci drawn are not identifiable in any brain that I 
have seen a record ol, and others which are recorded as 
constant can not be identified at all. It is not difficult to 
see from the drawings that the cerebral hemispheres were 
permitted to separate, the whole brain to flatten on its 
inferior surface, and that no successful attempt was made 
to retain the natural proportions of any of the parts. 
I would add that my observation on the Island of Reil, 
in the Orang, is distinctly contradictory of that of Dr. 
Chapman, who states it to be unconvoluted. One of the 
hemispheres in my possession is so prepared as to show 
the sulci and gyri breves of the Orang’s insula, which 
correspond as to their direction and relations to, though 
less numerous and well marked than, those of man. In 
every anthropoid dissected by myselt I find these gyri and 
sulci, and one sulcus, is a constant feature of even the 
Cynocephali. Dr. Chapman has, on a former occasion, 
asserted the cerebellum to be uncovered by the cerebrum 
in one of his Chimpanzees. I examined carefully both 
specimens that were sent to Philadelphia, and of which 
the Doctor obtained the brains after death. They did not 
differ in their external cranial configuration from the other 
Chimpanzees ; they were the healthiest, most active, and 
most intelligent of the species I have seen, and consider- 
ing the fact that in both of my specimens the cerebrum 
clearly overlapped, I was much surprised to find that 
Dr. Chapman had discovered an exception in one of the 
two animals* I had myself seen. Subsequently 
Doctor Parker demonstrated that Doctor Chapman’s 
observation was due to the imperfection of the 
methods followed. That the writer made erroneous in- 
ferences is clear from a statement in the very paper I am 
now commenting on. Dr. Chapman says, “ It happens, 
“ however, that I have lying in alcohol tor some years a 
“ number of human and animal brains. Among the latter, 
“examples of the genera Cebus, Ateles, Macacus, Cyno- 
“ cephalus, Cercopithecus, etc., taken out of the skull suf- 
“ ficiently carefully, but preserved in the rudest manner 
“wiihout any regard to the above precautions. Now, 
“ while all of these brains have somewhat lost their 
“ natural contour, they are not so changed that in a single 
“ one, human or monkey, do I find the cerebellum uncov- 
ered by the cerebrum, and in every instance the pos- 
“ terior lobes overlap the cerebellum to a greater extent 
“ than I find is the case in my Orang. If the cerebrum 
“ and cerebellum in the Orang and Chimpanzee invaria- 
“ bly bear the same proportion to each other as they do 
“in man and the monkeys, why should not the brain of 
“ an Orang or Chimpanzee, after lying in alcohol for some 
“years, exhibit the cerebellum covered by the cerebrum 
“ as in them ? Why should it be necessary to replace the 
“ brain of the Chimpanzee or the Orang in the skull to 
“ make plaster casts, etc., if there is no difference between 
‘‘their brains and those of man and the monkeys, for 
there is no necessity of having recourse to such meas- 
“ ures to prove that the cerebellum is covered in the 
“ latter? ” 
The above would be, to say the very least, a novel 
kind of argumentation, even if its assumptions were true. 
I have seen hundreds of brains taken out of the skull on 
post mortems of the human subject thrown on a slab, 
which would, if preserved (and in instances where they 
were preserved did), show an uncovered cerebellum. 
Why, Benedict of Vienna actually discovered that the 
cerebellum was uncovered in several criminals ! This 
discovery was speedily exposed as a crude fallacy by 
j Meynert and Heschl. It is remarkable that Dr. Chap- 
I man disposes with such facility, of the exact methods and 
relies so much on proofs which are, so to speak, the out- 
growth of accident. Now, in every instance where the 
* One of these was the black-faced variety which Du Chaillu attempted 
to make an extra species of (Not the Tschego.) 
