THE  CHIMPANZEE  AND  ORANG  UTAN. 
345 
is  illustrated  by  specimens  of  the  young  animal  only,  and  these  at  a  period  prior  to 
the  shedding  of  the  deciduous  teeth ;  the  skeletons  and  crania  of  the  Chimpanzee  in 
the  public  museums  of  this  metropolis  exhibit  its  bony  structure  in  the  same  immature 
state ;  and  it  is  improbable  that  the  enlightened  naturalists  of  other  European  nations 
would  suffer  so  great  an  osteological  treasure  as  the  skeleton  or  skull  of  the  full-grown 
Troglodyte  to  remain  hidden  (as  all  undescribed  specimens  may  be  said  to  be,)  in  their 
museums. 
This  remarkable  deficiency  in  the  means  of  determining  the  changes  which  take  place 
in  the  structure  of  the  Chimpanzee  during  its  passage  to  the  adult  state,  was  particularly 
felt  and  regretted  by  myself  while  engaged  in  investigating  the  anatomy  of  the  Orancj 
Utan,  on  the  occasion  of  the  death  of  the  young  animal  of  that  species  formerly  in  the 
possession  of  the  Zoological  Society.  Having  subsequently,  however,  been  informed 
of  the  existence  of  the  skeleton  of  an  adult  Chimpanzee  in  the  private  museum  of  a 
member  of  the  Society,  R.  B.  Walker,  Esq.,  Surgeon,  of  Curzon  Street,  I  apphed  to 
that  gentleman,  and  was  not  only  gratified  with  the  sight  of  his  valuable  and  unique 
specimen,  but  received  liberal  permission  to  describe  it,  and  had  every  facility  afforded 
to  me  for  that  purpose. 
The  animal  was  shot  by  a  European  at  Sierra  Leone,  and  the  clavicle  was  broken 
by  the  fall.  The  skeleton  was  prepared  by  the  ants,  sent  to  England,  and  presented  to 
Mr.  Walker,  but  without  any  information  as  to  the  habits  of  the  species.  The  bones 
are  perfect  in  every  respect,  with  the  exception  of  the  broken  clavicle  and  are  remark- 
ably well  articulated. 
The  general  appearance  and  proportions  of  the  skeleton  of  the  adult  Chimpanzee  are 
unquestionably  the  most  anthropoid  that  the  Quadrumanous  order  presents,  but  the 
deviations  from  the  human  structure  are  numerous  and  important. 
The  skull  is  of  a  narrow  elongated  figure,  slightly  contracting  towards  the  anterior 
part,  which  is,  as  it  were,  truncated,  from  the  depth  and  direction  of  the  symphysis  of 
the  lower  jaw.  Compared  with  the  rest  of  the  body  it  is  of  small  size,  owing  to  the 
arrested  development  of  the  cerebral  portion.  This  part,  or  the  cranium  properly  so 
called,  is  of  a  rounded  ovate  depressed  figure,  and  is  altogether  posterior  to  and  not 
above  the  face ;  which  slopes  forwards  at  an  open  angle,  as  in  the  Baboons.  The  exte- 
rior surface  of  the  cranium  is  smooth  and  convex  on  the  superior  or  coronal  aspect, 
being  devoid  of  the  intermuscular  frontal  and  sagittal  crests  which  give  so  strong  a  car- 
nivorous character  to  the  skull  of  the  mature  Orang.  The  extent  of  the  origins  of  the 
temporal  muscles  is,  however,  indicated  by  a  bony  boundary,  continued  from  the  outer 
part  of  the  supra-orbital  ridge,  at  first  as  a  well-marked  crest,  but  soon  subsiding  to  a 
shghtly  elevated  line,  which  extends  backwards  along  the  parietal  bone  about  an  inch 
from  the  sagittal  suture,  and  is  lost  in  the  lambdoidal  and  supra-auditory  ridges.  The 
difference  between  the  adult  and  young  skulls  in  the  extent  of  the  surface  of  cranium 
affording  origin  to  the  temporal  muscle  is  considerable,  as  might  be  expected  from  the 
