326 
SCIENCE. 
Tribune in these cases, which were submitted to the 
authors on the 4th of December last for correction or re- 
jection ; no objection being made we printed them in a 
recent number. After publication Professor Agassiz now 
writes that the reports under his name are not satisfactory 
to him. We therefore request our readers to consider 
them withdrawn. 
Professor George F. Barker, Professor O. C. Marsh 
and Professor J. E. Hilgard are preparing more elaborate 
reports of their important papers, and promise them at 
an early day. 
THE BRAIN OF THE ORANG.* 
BY HENRY C. CHAPMAN, M.D. 
The brain of the Orang has been figured by Tiede- 
mann, Sandifort, Schroeder van der Kolk and Vrolik, 
Gratiolet, Rolleston, etc. On account, however, of the 
few illustrations extant, and of the importance of the 
subject, I avail myself of the opportunity of presenting 
several views of my Orang’s brain (Figs. 1 to 5), which 
was removed from the skull only a few hours after 
death. The membranes were in a high state of conges- 
tion, and a little of the surface of the left hemisphere had 
been disorganized by disease, otherwise the brain was in 
good condition. It weighed exactly ten ounces. The 
brain of the Orang in its general contour resembled that 
of man more than those of either of the Chimpanzees 
which I examined. In these the brain was more elong- 
ated. The general character of the folds and fissures in 
the brain of the Orang, Chimpanzee, and man are the 
same ; there are certain minor differences, however, in 
their disposition in all three. The fissure of Sylvius in 
the Orang runs up and down the posterior branch pur- 
suing only a slightly backward direction ; the anterior 
branch is small. The fissure of Rolando, or central fis- 
sure, quite apparent, is, however, situated slightly more 
forward in the Orang than in man. It differentiates the 
frontal from the parietal lobe. The parieto-occipital fis- 
pure is well marked ; bordered externally by the first oc- 
cipital fold it descends internally on the mesial side of the 
hemisphere, separating the parietal from the occipal lobes. 
* From the Proceedings of the Academy of Natural Sciences, Phila.,1880. 
in the Orang, the parieto-occipital fissure does not reach 
the calcarine, being separated from it by the “deuxieme 
plis de passage interne” of Gratiolet, or “ untere innere 
Scheitelbogen- Windung ” of Bischoff. I have noticed this 
separation as an anomaly more than once in man. 
According to Bischoff, this disposition obtains in the 
Gorilla, and seems to be usual also in the Chimpanzee. 
In the female Chimpanzee, however, on the left side 1 
found the parieto-occipital fissure passing into the cal- 
carine, as in man. The frontal lobe is easily distin- 
guished from the parietal by the fissure of Rolando, and 
from the temporal by the fissure of Sylvius. In the 
Orang it is higher, wider, and more arched than in the 
Chimpanzee. The anterior central convolution in front 
of the central fissure runs into the post-central convolu- 
tion above and below, as in man. It is difficult, however, 
to identify the three frontal convolutions seen in man and 
the Chimpanzee, the frontal lobe of the Orang dividing 
rather into two convolutions, the middle one being badly 
defined. This is due somewhat to the length of the pre- 
central fissure, which is as long as the fissure of Rolando, 
extending farther upward than in man. There was 
nothing particularly noticeable about the base of the 
frontal lobe ; on the mesial surface it ran into the 
parietal. The part above the calloso-marginal fissure in 
the Orang is not as distinctly divided into convolutions as 
in man, though these are not constantly present even in 
all human brains. The parietal lobe is separated from 
the frontal by the central fissure, from the occipital and 
temporal incompletely, by the parieto-occipital and 
Sylvian fissures. The posterior-central convolution is 
well defined. The parietal fissure in the Orang is more 
slrikingthan that of man, resembling the Gorilla’s ; it is 
twice as long as the corresponding fissure in the Chim- 
panzee, extending from the transverse occipital fissure, as 
is sometimes the case in man, almost into the fissure of 
Rolando. It is unbridged and without a break, and 
divides the parietal lobe completely into upper and lower 
parietal lobules. The upper parietal lobule is bounded 
externally by the parietal fissure ; posteriorly it is sep- 
arated from the occipital lobe, internally by the parieto- 
FlG. 2. 
occipital fissure ; externally it is continuous with the oc- 
cipital lobe, as the first occipital gyrus, anteriorly it is 
separated from the posterior central convolution more 
completely than in mar, by a fissure which runs paraded 
with the central fissure. There is in the Orang, also, a 
fissure running paraded with the parietal, which sub- 
divides the upper parietal lobule into inner and outer 
portions. The precuneus, or the space on the mesial 
side of the parietal lobe between the parieto-occipital 
