THE CHIMPANZEE AND ORANG UTAN. 345 
is illustrated by specimens of the young animal only, and these at a period prior to 
the shedding of the deciduous teeth; the skeletons and crania of the Chimpanzee in 
the public museums of this metropolis exhibit its bony structure in the same immature 
state ; and it is improbable that the enlightened naturalists of other European nations 
would suffer so great an osteological treasure as the skeleton or skull of the full-grown 
Troglodyte to remain hidden (as all undescribed specimens may be said to be,) in their 
museums. 
This remarkable deficiency in the means of determining the changes which take place 
in the structure of the Chimpanzee during its passage to the adult state, was particularly 
felt and regretted by myself while engaged in investigating the anatomy of the Orang 
Utan, on the occasion of the death of the young animal of that species formerly in the 
possession of the Zoological Society. Having subsequently, however, been informed 
of the existence of the skeleton of an adult Chimpanzee in the private museum of a 
member of the Society, R. B. Walker, Esq., Surgeon, of Curzon Street, I applied to 
that gentleman, and was not only gratified with the sight of his valuable and unique 
specimen, but received liberal permission to describe it, and had every facility afforded 
to me for that purpose. 
The animal was shot by a European at Sierra Leone, and the clavicle was broken 
by the fall. The skeleton was prepared by the ants, sent to England, and presented to 
Mr. Walker, but without any information as to the habits of the species. The bones 
are perfect in every respect, with the exception of the broken clavicle and are remark- 
ably well articulated. 
The general appearance and proportions of the skeleton of the adult Chimpanzee are 
unquestionably the most anthropoid that the Quadrumanous order presents, but the 
deviations from the human structure are numerous and important. 
The skull is of a narrow elongated figure, slightly contracting towards the anterior 
part, which is, as it were, truncated, from the depth and direction of the symphysis of 
the lower jaw. Compared with the rest of the body it is of small size, owing to the 
arrested development of the cerebral portion. This part, or the cranium properly so 
called, is of a rounded ovate depressed figure, and is altogether posterior to and not 
above the face ; which slopes forwards at an open angle, as in the Baboons. The exte- 
rior surface of the cranium is smooth and convex on the superior or coronal aspect, 
being devoid of the intermuscular frontal and sagittal crests which give so strong a car- 
nivorous character to the skull of the mature Orang. The extent of the origins of the 
temporal muscles is, however, indicated by a bony boundary, continued from the outer 
part of the supra-orbital ridge, at first as a well-marked crest, but soon subsiding toa 
slightly elevated line, which extends backwards along the parietal bone about an inch 
from the sagittal suture, and is lost in the lambdoidal and supra-auditory ridges. The 
difference between the adult and young skulls in the extent of the surface of cranium 
affording origin to the temporal muscle is considerable, as might be expected from the 
