THE  CHIMPANZEE  AND  ORANG  UTAN. 
367 
patella  is  smaller  in  proportion  than  in  Man,  is  of  an  oval  shape,  and  has  a  single  arti- 
cular surface  without  any  ridge. 
The  tarsus  has  the  same  number  of  bones  ;  and  they  have  nearly  the  same  forms  as 
in  the  Chimpanzee,  but  admit  of  freer  motion  on  each  other,  and  constitute  a  relatively 
smaller  proportion  of  the  entire  foot.  The  astragalus  has  its  articular  surface  more 
oblique,  and  the  foot  in  consequence  is  more  turned  inwards  ;  this  bone  is  much  flatter 
than  in  the  human  subject.  The  os  calcis  does  not  project  so  far  backwards  as  in  the 
Chimpanzee;  it  is  small  and  compressed.  Lawrence  aptly  remarks,  that  "this  single 
bone  is,  therefore,  an  infallible  characteristic  of  Man;  and  'ex  calce  hominem'  would 
probably  be  a  safer  rule  than  'ex  pede  HeTculem\'"^  The  internal  cuneiform  bone 
recedes  most  from  the  human  type  in  its  greater  production  or  development  towards  the 
plantar  aspect,  and  in  having  the  surface  of  articulation  for  the  hallux,  or  great  toe, 
below  the  range  of  the  other  articular  surfaces.  The  metatarsal  bones  (that  of  the  hallux 
excepted)  are  much  longer,  more  concave  towards  the  sole,  and  have  greater  inter- 
spaces than  the  human.  The  metatarsal  bone  of  the  second  toe  has  its  articulation  with 
the  tarsus  on  the  same  line  as  the  rest :  the  metatarsal  bone  of  the  hallux  extends  very 
little  beyond  the  middle  of  the  preceding,  and  stands  off  from  it  at  an  acute  angle. 
The  peculiarity  of  the  structure  of  the  hinder  thumb,  viz.  its  having  but  one  bone,  and 
consequently  no  nail,  was  first  observed  by  Camper^,  who  found  it  to  be  the  case  in  seven 
out  of  eight  Orangs  which  he  had  the  opportunity  of  examining.  In  the  Orang  Utan  de- 
cribed  by  M.  Fred.  Cuvier,  however,  it  is  expressly  stated,  "  Tous  les  doigts  des  pieds 
avoient  la  meme  structure  que  ceux  de  la  main  et  etoient  tres-libres  dans  leurs  mouve- 
mens  ;  et  tous,  sans  exception,  avoient  leurs  ongles."^  In  the  individual  dissected  at 
the  Museum  of  the  Zoological  Society,  (October  1830,)  the  great  toes  had  very  perfect 
but  small  black  nails,  and  also  two  phalanges  in  addition  to  the  metatarsal  bone :  the 
same  number  of  phalanges  exists  in  the  natural  skeleton  of  Lord  Amherst's  Orang  pre- 
served in  the  Museum  of  the  College  of  Surgeons,  so  that  these  exceptions  much  di- 
minish the  importance  of  this  circumstance  as  a  generic  or  specific  character^. 
The  phalanges  of  the  other  toes  are  remarkably  elongated ;  those  of  the  first  series 
are  curved  ;  the  middle  toe  exceeds  the  rest  in  length  ;  the  concavity  of  the  great  toe 
is  turned  more  towards  the  other  toes  than  in  the  Chimpanzee  :  but  the  chief  difference 
which  obtains  in  the  bony  structure  of  the  foot  is  in  the  relative  length  of  the  hind 
thumb.    In  the  Orang  it  does  not  reach  to  the  condyle  of  the  adjoining  metatarsal 
•  Lectures,  p.  144.  -  CEuvres,  torn.  i.  p.  54.  ^  Annales  du  Museum,  torn.  xvi.  p.  48. 
*  Since,  in  addition  to  this,  the  intermaxillary  sutures  are  obliterated  at  the  development  of  the  great  cus- 
pidati,  the  generic  character  proposed  by  Dr.  Leach  for  the  Simia  Satyrus  will  be  unexceptionable  in  only 
one  particular. 
"  PiTHEcus.  Os  intermaxillaire  parfaitement  distinct ;  point  de  ligament  suspenseur  de  la  cuisse  ;  laderniere 
phalange  du  pouce  du  pied  manque,  et  par  consequent  point  d'ongle  a  ce  pouce." — Journal  de  Physique, 
torn.  Ixxxix.  p.  159. 
3  c  2 
