APES. 449 



acquire their full development and functional position. In the female 

 the point of the canines sometimes pierces the gum before the last 

 molar has come into place. 



The concomitant change which takes place not only in the size 

 but shape of the jaws is so considerable, and gives rise to such re- 

 markable modifications in the exterior of the cranium and the facial 

 angle, that the mature and immature states of the Simia Wurmbii 

 were for some time regarded by Naturalists as distinct species, under 

 the names of Orang {Simia Satyrus, Linn.) and Pongo {Papio Wurmbi, 

 Latr.). Nor is it surprising that the transition from the Orang to 

 the Hottentot should seem to be so gradual and easy, the cranial 

 characters of the supposed adult anthropoid Quadrumane being 

 those of a young animal with a full-sized brain and with deci- 

 duous teeth. Had the skull of the mature Chimpanzee been 

 transmitted from Africa at the period when Wurmb's Pongo 

 was placed in the Mammalian Systems of Cuvier,(l) Fischer, (2) 

 and other Naturalists, as a distinct species, far below the Simia 

 Satyrus, it would most probably have been mistaken for that 

 of a lower, baboon-like Quadrumane. But its first description 

 was accompanied by a demonstration of the concealed germs of 

 the permanent teeth in the jaws of the young Chimpanzee, which 

 established the true nature of the adult cranium ; the paternal 

 relation of the great Pongo of Wurmb to the young Orang being 

 demonstrated by the same evidence. (3) 



The jaws of these highly organized Simice, during the acquisition 

 of the large permanent series of teeth, not only rapidly increase, 

 but a considerable change takes place in the extent of origin of 

 the temporal muscle : this leaves a well-marked impression near the 

 vertex in the Chimpanzee, and in the male Orang meets its fellow at 

 the vertex and stimulates the growth of a strong osseous crest. 

 The mastoid ridge also shifts its place, and retreats by progressive 

 absorption and deposition nearer to the plane of the occipital region 



(1) Regne Animal, Ed. 1817, p. 111. 



(2) Synopsis Mammalium, 1829, p. 32. Fischer thus concludes his description of the 

 /Simia Wurmhii : — " Sunt, qui hanc speciem pro <S. Satyro adulta ducant. Permulta tamen 

 sententise isti repugnare videntur." He does not cite any of the grounds of opposition. 



(3) See Zoological Transactions, vol. i, p. 343. 



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