
THE CHIMPANZEE AND ORANG UTAN. 349 
separate intermaxillaries was first discovered by the immortal Géthe', scarcely a line’s 
breadth intervenes between the incisive foramina and the alveoli of the anterior in- 
cisors. 
The lower jaw, like the upper, is equally characterized by its strength and size in 
relation to the entire skull; the symphysis, or chin, recedes ; but the depth of the jaw 
in front is less than in the Orang. The alveoli, however, advance more nearly to 
the level of the condyle than in the Orang, and the jaw consequently in this respect 
proportionally approximates the structure of the brute. The coronoid process rises 
a little higher than the condyle, but does not quite attain the level of the zygoma. 
The ramus of the jaw forms a more open angle with the body than in the Orang, and 
thus more nearly resembles the human structure. The mental foramen is single on 
either side. 
The dental formula of the adult Chimpanzee, like that of the other Catarrhine Simie, 
is the same as in the human subject, viz. Incisores +, Luniarti 3, Bicuspides +, Mo- 
lares ¢. The teeth approximate in their proportionate size much more nearly than those 
of the Orang to the human teeth; but they manifest in their relative position the absence 
of that character which, with one anomalous exception”, is peculiar, among Mammalia, 
to Man, viz. unbroken proximity. A well-marked interval separates the upper laniaries 
from the contiguous incisors, and the lower laniaries are removed by a smaller interval 
from the contiguous bicuspides: these intervals admit the apices of the large laniaries 
respectively of the opposite jaws when the mouth is closed. The absence of similar 
vacancies in the dental series of Man is owing to the shortness of the jaws, and to the 
equable development of the different teeth, and especially the laniaries, the points of 
which are opposed to one another. The formidable cuspidati, which supply the beast 
of prey with his weapons of destruction, and afford to the irrational ape his means of 
defence, are unnecessary in the master of the animal creation, who can contrive and vary 
at will more effective instruments for both purposes. 
The fangs of the teeth in the Chimpanzee are proportionate to the size of their crowns ; 
but the accompanying figures (Plates LI. and LII.) supersede the necessity of a parti- 
cular description of these parts. Some modifications of the skull may, however, be 
noticed in reference to the powers of mastication. 
As the strong nasal bones and contiguous processes of the maxillary and frontal 
bones, which constitute the wide inter-orbital space of the skulls of the Carnivora, are 
possessed in a comparatively feeble degree by the Orangs, the upper jaw is strengthened, 
and the weak ethmoid bone defended from the effects of the powerful forces that tend 
to push it upwards, by a thickening of the outer rim of the orbit, and by the enlarge- 
ment of the malar bone, against which the malar process of the superior maxillary bone 
is firmly abutted, and is thus enabled to resist the pressure of the lower jaw. The en- 
tire ramus of the lower jaw, and the coronoid process more especially, are thickened and 
' Zur Naturwissenschaft, &c. zur Morphologie, B.i. 8vo. 1817. 2? In the fossil genus Anoplotherium, Cuv. 
VOL. I. 3A 
