THE  CHIMPANZEE  AND  ORANG  UTAN. 
349 
separate  intermaxillaries  was  first  discovered  by  the  immortal  Gothe  ^  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  Simiee, 
is  the  same  as  in  the  human  subject,  viz.  Incisores  ^,  Laniarii  -f,  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.  3  A 
