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MR.  R.  OWEN  ON  THE  OSTEOLOGY  OF 
pressed  from  before  backwards.  An  error  which  has  crept  into  the  excellent  and  labo- 
rious work  on  Comparative  Anatomy  which  the  lamented  death  of  the  celebrated 
Meckel  has  left  unfinished,  requires  here  to  be  noticed,  as  it  attributes  a  community  of 
structure  to  the  two  species  of  Orang  in  a  part  which  affords .  one  of  the  best-marked 
differences.  The  head  of  the  femur,  which  presents  a  smooth  unbroken  surface  in  the 
Orang,  is  marked  with  the  pit  for  the  attachment  of  the  lig amentum  teres  as  well  in  the 
adult  as  in  the  young  Chimpanzee,  in  which  I  have  ascertained  the  existence  of  that 
ligament  in  a  dissection  of  a  recent  specimen.  Meckel  describes  the  absence  of  the 
lig  amentum  teres  in  the  Pongo  as  well  as  in  the  Orang,  and  this  is  the  case  ;  but  it  is 
only  another  of  the  many  coincidences  of  structure  which  prove  the  identity  of  the  two 
animals.  This  peculiarity  of  the  hip-joint  appears  to  relate  to  the  disproportionate 
shortness  of  the  legs  in  Simia  Satyrus ;  but  the  deterioration  which  they  consequently 
suffer,  as  means  of  support,  is  compensated  by  the  advantages  which  they  gain  as  instru- 
ments of  prehension,  their  extent  and  variety  of  motion  being  increased  by  the  removal 
of  a  ligament  that  acts  as  an  impediment  to  both  in  the  animals  which  possess  it. 
The  tibia  in  the  Chimpanzee  is  proportionally  thicker  at  the  upper  end,  and  the 
fibula  considerably  stronger  at  the  lower  end,  than  in  Man :  the  interosseous  space 
is  wider,  and  the  anterior  convexity  of  both  bones  may  be  perceived  to  be  slightly 
increased.    The  patellcB  are  proportionally  smaller. 
The  relative  size  and  position  of  the  tarsal  bones  more  nearly  correspond  to  the  same 
in  the  human  subject  than  is  found  in  any  other  Quadrumanous  animal ;  but  the  de- 
viations, though  slight,  are  nevertheless  indicative  of  the  habit  of  turning  the  foot  from 
the  position  necessary  for  supporting  the  body,  to  that  which  is  best  adapted  for  the 
readier  application  of  the  sole  to  the  branches  of  trees  for  the  purposes  of  cfimbing,  viz. 
with  the  outer  or  fibular  edge  of  the  foot  inclined  to  the  ground  ;  such  a  position  being 
evidently  most  in  accordance  with  the  natural  connexions  of  the  bones  of  the  tarsus. 
The  OS  calcis  is  relatively  feeble  as  compared  with  that  of  Man,  being  more  compressed 
from  side  to  side,  and  smaller  in  all  its  dimensions ;  but  it  projects  backwards  to  a 
greater  proportional  degree  than  in  the  Orang  or  inferior  Simia.  From  the  inchnation 
of  the  tarsus  to  rest  on  its  outer  edge,  the  os  navicular e  is  further  developed  downwards, 
so  as  to  project  considerably  below  the  bones  of  the  same  row  without  inconvenience 
from  pressure  on  the  sole.  The  internal  cuneiform  bone  has  a  corresponding  inclination, 
and  thus  the  hallux,  or  great  toe  or  hind  thumb,  is  attached  to  the  tarsus  in  a  position 
best  adapted  for  its  being  applied  as  an  opposable  instrument  to  the  other  toes.  The 
whole  foot  of  the  Chimpanzee  is  relatively  narrower  and  longer  than  in  Man-,  and  the 
digital  phalanges  are  more  inflected  towards  the  sole.  The  admeasurements  in  the  Table 
show  the  relative  length  of  the  hinder  thumb,  and  other  parts  of  the  foot  in  the  Chim- 
panzee and  Orang. 
The  organization  of  the  lower  extremities  evidently  bespeaks  a  creature  destined 
to  reside  in  forests  ;  and  the  modifications  of  the  bony  structure,  w^hich  add  to  the  fa- 
