﻿Dr. 
  P. 
  Ferrier 
  on 
  the 
  Brain 
  of 
  Monkeys. 
  

  

  415 
  

  

  Here 
  it 
  must 
  be 
  noted 
  that 
  the 
  centres 
  which 
  cause 
  the 
  above- 
  

   described 
  movements 
  of 
  the 
  hind 
  leg, 
  as 
  well 
  as 
  those 
  afterwards 
  

   to 
  be 
  described 
  which 
  cause 
  clenching 
  of 
  the 
  fist, 
  had 
  been 
  under 
  

   stimulation 
  previous 
  to 
  the 
  exploration 
  of 
  this 
  region. 
  Hence 
  

   the 
  result 
  is 
  to 
  be 
  looked 
  upon 
  as 
  the 
  combined 
  action 
  of 
  all 
  three 
  

   centres. 
  This 
  is 
  the 
  real 
  difficulty 
  experienced 
  in 
  analysis 
  of 
  the 
  

   complex 
  movements 
  of 
  the 
  limbs, 
  there 
  being 
  always 
  a 
  tendency 
  

   to 
  have 
  complications 
  arising 
  from 
  the 
  irritable 
  condition 
  which 
  

   continues 
  in 
  the 
  regions 
  which 
  have 
  been 
  under 
  experimentation. 
  

   This, 
  along 
  with 
  the 
  tendency 
  to 
  convulsive 
  spasms 
  of 
  a 
  choreic 
  

   or 
  epileptiform 
  nature, 
  lasting 
  for 
  minutes 
  after 
  the 
  cessation 
  of 
  

   stimulation, 
  renders 
  it 
  frequently 
  excessively 
  difficult 
  to 
  draw 
  

   accurate 
  conclusions. 
  The 
  results 
  described 
  have 
  always 
  been 
  those 
  

   arrived 
  at 
  after 
  as 
  complete 
  exclusion 
  as 
  possible 
  of 
  these 
  adverse 
  

   conditions. 
  

  

  VI. 
  Retraction 
  and 
  straightening 
  out 
  of 
  the 
  left 
  arm, 
  as 
  already 
  

   described. 
  

  

  VII. 
  Noted 
  as 
  action 
  of 
  the 
  latissimus 
  dorsi, 
  this 
  being 
  regarded 
  

   as 
  the 
  chief 
  cause 
  of 
  the 
  movement. 
  

  

  VIII. 
  In 
  this 
  case 
  the 
  shoulder 
  was 
  first 
  elevated, 
  the 
  humerus 
  

   adducted, 
  the 
  wrist 
  and 
  hand 
  fully 
  extended, 
  and 
  the 
  whole 
  arm 
  

   straightened 
  and 
  drawn 
  backward 
  in 
  the 
  manner 
  already 
  described 
  

   in 
  II. 
  

  

  IX. 
  Left 
  arm 
  adducted, 
  and 
  then 
  extended 
  and 
  retracted. 
  

  

  X. 
  A 
  similar 
  result. 
  

  

  XI. 
  Not 
  explored. 
  

  

  XII. 
  Not 
  explored. 
  

  

  XIII. 
  Action 
  of 
  the 
  latissimus 
  dorsi 
  as 
  already 
  described. 
  The 
  con- 
  

   dition 
  of 
  the 
  hand 
  is 
  not 
  noted. 
  

  

  The 
  results 
  of 
  stimulation, 
  therefore, 
  of 
  this 
  region 
  agree 
  with 
  each 
  

   other. 
  

  

  I 
  have 
  observed 
  frequently 
  that 
  only 
  very 
  partial 
  action 
  was 
  occa- 
  

   sionally 
  obtained 
  at 
  some 
  points 
  in 
  this 
  circle 
  ; 
  sometimes 
  only 
  an 
  appear- 
  

   ance 
  of 
  adduction 
  of 
  the 
  arm 
  . 
  The 
  complete 
  action, 
  however, 
  appears 
  to 
  

   be 
  such 
  as 
  I 
  have 
  described 
  as 
  resulting 
  from 
  stimulation 
  of 
  the 
  centre 
  of 
  

   this 
  circle. 
  

  

  Circle 
  \^J-> 
  ^g 
  s 
  * 
  1 
  & 
  2, 
  corresponding 
  to 
  the 
  posterior 
  third 
  of 
  the 
  

  

  superior 
  frontal 
  convolution. 
  

  

  I. 
  The 
  results 
  in 
  this 
  case 
  were 
  not 
  very 
  definite. 
  They 
  consisted 
  in 
  a 
  

   complication 
  of 
  the 
  movements 
  of 
  the 
  leg, 
  already 
  described 
  as 
  

  

  resulting 
  from 
  circle 
  f 
  2 
  \ 
  along 
  with 
  an 
  extension 
  forwards 
  of 
  

  

  the 
  right 
  arm. 
  

  

  