32 



face is directed moie outvvardly. Tlie foramen magnum is thrown 

 back to about the miJdle of tlie posteiior third of llie base of the 

 skull, and its plane is inclined from before upvvards at an angle of 5°. 

 There are no posterior cox\Ay\o\d f or aminą. Tlie styloid process is re- 

 piesented by a very small tuberosity. A considerable space inter- 

 venes betvveen t\\e foramen magiium and the bony palate, which it- 

 self equally exceeds the corresponding portion of the human skull. 

 The zygomatic archesare opposite to the middle third of the cranium 

 as seen from belovv, in which position also the contraction of the 

 skull betvveen the zygomala ofiers a marked distinction from that of 

 Man. 



In the front vievv of the cranium, the threatening supraclliary ridges 

 almost hide the cephalic cavity from view ; and the latter, instead of 

 forming a broad back-ground to the face, as in the young Chimpan- 

 zee, and still more in Man, is siirpassed in breadth by the lateral 

 boundaries of the orbits and the zygomatic arches. The orbits are 

 seated higher than in the Orang, and are larger in proportion; but 

 their plane is more perpendicular, and they are wider apart. In 

 neither the Chimpanzee nor the Orang is there a supraorbitary 

 foramen, but its place is marked by a slight groove. The lachrymal 

 bones are entirely confined to the orbit. A character by which the 

 Chimpanzee approximates more closely than the Orang to the human 

 subject is found in the nasal bone, which projects in a slightly arched 

 form beyond the interorbital plane, and exhibits at its lovver margin 

 a trace of its original separation into two lateral portions: it is an- 

 chylosed with the osfrontis and the suture obliterated. The malar 

 bones are largely developed, and two or three smaM foramina are 

 observable in the process on the outside of the orbit. The contour 

 of the upper jaw from the nasal aperture to the incisor teeth is almost 

 straight, vvhile in the Orang it is rendered concave by the greater 

 development of the alveolar processes of the intermaxillary bones. 

 The obliteration of the suturės between these bones and the upper 

 maxillary takes place at a much earlier period in the Chimpanzee 

 than in the Orang ; although in the young animal, when the first 

 dentition is complete, traces of the original separation are still 

 visible. The situation oi i\\e foramina incisiva is alvvays indicative 

 of the original extent of these bones, and in no Mammal do they 

 approximate so closely to the incisive teeth as in Man. The infra- 

 orbitary canal opens upon the face by a singie ybranien : Mr. Ovven 

 has observed a second in one young specimen, but never more. In 

 the Orang there are usually three or more, as in many of the inferior 

 Simice. The lower jaw, likę the upper, is characterized by itsstrength 

 and relative size. Its symphysis recedes, but the depth at this part 

 is much less than in the Orang. The alveoli advance more nearly 

 to the level of the condyle, and conseąuently approximate propor- 

 tionally to the structure of the brute; the mental /oraraere is single. 



Mr. Ovven next proceeds to notice the dental ybrmuZa and the 

 characters of the teeth ; and observes particularly on the modifica- 

 tions in their arrangement and relative position consequent on the 

 preponderating development of the cuspidatus. He also points out 



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