ea 
THE CHIMPANZEE AND ORANG UTAN. 359 
in the Chimpanzee and the higher Quadrumana, they are confined to the orbit. The os 
male is distinguished by several large foramina in its orbital process, which lead from 
its facial superficies into the orbit. The superior maxillary bone differs from that of 
the Chimpanzee, in being perforated by three infraorbitary foramina instead of one, as 
well as in the greater magnitude which it acquires in consequence of the large laniaries 
which are implanted in it'. From the great anterior development of these bones and of 
the intermaxillaries, the incisors project more obliquely forwards than in the Chimpanzee. 
Now in all the peculiarities of the Orang’s skull which are independent of the changes 
consequent upon the second dentition, we find an exact correspondence between the 
Simia Satyrus, or young animal, and the Pongo, or adult. Their crania equally exhibit 
the absence of the projecting supraciliary ridges, the presence of the double anterior 
condyloid foramina, the numerous infraorbitary foramina, and those in the malar bone, 
the same disposition of the cranial sutures, the same form of the os nasi, and the same 
difference from the Chimpanzee in the contraction of the interorbital space. The cha- 
racters of the lower jaw, by which it differs from that of the Chimpanzee, viz. the greater 
height and breadth of the rami and the greater depth of the symphysis, are equally ma- 
nifested in the young as in the old Simia Satyrus. 
In following out the same observations with regard to the germs of the permanent 
teeth in the young Orang, the same satisfactory results are obtained in reference to their 
identity with those which are fully developed in the old animals, as were previously de- 
tailed in the account of the Chimpanzee?. 
In the young Orang, with three molars in use on either side of each jaw, it is easy to 
see that the last is of a different set from the two smaller ones that stand before it. Its 
grinding surface exhibits the cuspides entire and sharp, and all the radiating furrows as 
if freshly impressed upon it ; while the same surface in the deciduous molares is smooth, 
the crown worn down, and part of the fangs are protruded from the socket. The small 
laniary stands off at a distance from the neighbouring molar, and a still greater interval 
' Among the differences that have been pointed out in the crania of the young Orang and Pongo, in sup- 
port of the theory of their specific difference, one has been insisted upon which relates to the size of the antrum 
mazillare. It would be difficult to decide this point without making the necessary sections to expose the cavity ; 
but I may observe, that what appears to be a greater extension of the antrum backwards in the young Orang, 
is the bulbous projection produced by the still inclosed molar teeth, and which consequently is not to be ob- 
served after their complete development in the adult skull; and that in the Pongo, so far from the antrum being 
so diminutive that “it can be hardly said to exist at all” (Harwood, Ibid., p. 473.), it is really of a fair propor- 
tionate size. Its dimensions in a cranium of this animal, which measures from the occiput to the muzzle 104 
inches, being in the antero-posterior diameter 2 inches and 5 lines, in the lateral diameter 1 inch and 6 lines, in 
height 2 inches. 
? T have subsequently found that the large size of the germs of the permanent teeth in the young Orang 
were noticed by Professor Rudolphi, who inferred from them that the adult Orang must equal in size the Pongo 
of Wurmb ; but as he was unable to compare them with the teeth of that animal, the proof of their identity was 
still to a certain extent incomplete. See Berlin Transactions for 1824, p. 131. 
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