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  Dr. 
  D. 
  Ferrier 
  on 
  the 
  Brain 
  of 
  Monkeys. 
  

  

  II. 
  Here 
  also 
  extension 
  forwards 
  of 
  the 
  left 
  arm 
  and 
  also 
  of 
  the 
  leg. 
  

  

  It 
  is 
  to 
  be 
  noted 
  that 
  the 
  leg-centres 
  had 
  been 
  already 
  under 
  

   stimulation 
  previous 
  to 
  exploration 
  of 
  this 
  centre. 
  

  

  III. 
  Extension 
  forwards 
  of 
  the 
  right 
  arm 
  and 
  hand. 
  

  

  IY. 
  The 
  results 
  were 
  not 
  very 
  definite, 
  as 
  the 
  animal 
  was 
  continually 
  

   being 
  thrown 
  into 
  convulsive 
  spasms 
  on 
  application 
  of 
  the 
  elec- 
  

   trodes. 
  

  

  Y. 
  The 
  right 
  arm 
  and 
  hand 
  are 
  extended 
  forwards, 
  as 
  if 
  to 
  touch 
  or 
  

   reach 
  something 
  in 
  front. 
  

  

  VI. 
  Not 
  explored. 
  

  

  VII. 
  Sapid 
  extension 
  forwards 
  of 
  the 
  whole 
  right 
  arm 
  and 
  hand. 
  

  

  VIII. 
  Similar 
  action. 
  

  

  IX. 
  The 
  left 
  arm 
  is 
  outstretched, 
  as 
  if 
  to 
  touch 
  some 
  object 
  in 
  front. 
  

  

  X. 
  Not 
  explored. 
  

  

  XI. 
  Similar 
  result. 
  

  

  XII. 
  Not 
  explored. 
  

  

  XIII. 
  Indefinite 
  result, 
  but 
  apparently 
  resembling 
  IX. 
  

  

  Excluding 
  complication 
  due 
  to 
  conjoint 
  irritation 
  of 
  the 
  leg-centres, 
  

   the 
  results 
  indicate 
  a 
  centre 
  for 
  a 
  definite 
  forward 
  extension 
  of 
  the 
  arm. 
  

  

  Ascending 
  parietal 
  convolution 
  (J), 
  (T), 
  f^T)j 
  figs. 
  1 
  & 
  2. 
  

  

  This 
  is 
  marked 
  by 
  the 
  letters 
  a, 
  b, 
  c, 
  and 
  d, 
  indicating 
  circles 
  extending 
  

   from 
  the 
  centre 
  of 
  the 
  convolution 
  to 
  the 
  fissure 
  of 
  Rolando 
  and 
  intra- 
  

   parietal 
  sulcus 
  respectively. 
  

  

  Owing 
  to 
  the 
  fact 
  that 
  many 
  individual 
  variations 
  exist 
  in 
  the 
  results 
  

   obtained, 
  they 
  are 
  detailed 
  with 
  more 
  fulness 
  in 
  each 
  case 
  in 
  the 
  order 
  of 
  

   the 
  experimentation, 
  care 
  being 
  taken 
  to 
  compare 
  accurately 
  correspond- 
  

   ing 
  regions. 
  The 
  divergences 
  are 
  in 
  a 
  great 
  measure 
  to 
  be 
  explained 
  by 
  

   the 
  fact 
  that 
  the 
  movements 
  caused 
  involve 
  the 
  conjoint 
  action 
  of 
  the 
  

   flexor 
  and 
  extensor 
  muscles 
  of 
  the 
  wrist 
  and 
  fingers, 
  and 
  hence 
  move- 
  

   ments 
  of 
  an 
  apparently 
  opposite 
  character 
  seem 
  to 
  result 
  from 
  stimulation 
  

   of 
  the 
  same 
  point. 
  A 
  differentiation 
  of 
  centres 
  for 
  extension 
  and 
  centres 
  

   for 
  flexion 
  could 
  not 
  be 
  made 
  out. 
  

  

  I. 
  a. 
  Flexion 
  of 
  the 
  fingers 
  of 
  the 
  right 
  hand, 
  abduction 
  of 
  the 
  thumb, 
  

  

  and 
  slight 
  rotation 
  outwards 
  of 
  the 
  wrist. 
  

  

  b. 
  A 
  similar 
  action, 
  but 
  at 
  the 
  same 
  time 
  the 
  humerus 
  is 
  

   adducted. 
  

  

  c. 
  Similar 
  to 
  h. 
  

  

  d. 
  Pronation 
  of 
  hand 
  and 
  flexion 
  of 
  the 
  thumb 
  and 
  fingers. 
  

   Longer 
  stimulation 
  gave 
  rise 
  to 
  clonic 
  spasms 
  of 
  the 
  wrist 
  and 
  

  

  fingers, 
  continuing 
  several 
  seconds. 
  

  

  II. 
  d. 
  Sudden 
  and 
  quick 
  extension 
  of 
  the 
  wrist, 
  and 
  slightly 
  of 
  the 
  

   fingers. 
  

  

  