﻿1875.] 
  

  

  On 
  Cerebral 
  Lobes 
  in 
  Higher 
  Vertebrata. 
  

  

  563 
  

  

  The 
  results 
  for 
  this 
  station 
  are 
  : 
  — 
  , 
  „ 
  

  

  Variation 
  V= 
  28 
  27 
  24 
  

  

  Dip 
  D= 
  53 
  49 
  46 
  

  

  Horizontal 
  force 
  X= 
  4-3798 
  

  

  Magnetic 
  moment 
  . 
  . 
  . 
  .m= 
  0-4271 
  

   Total 
  force 
  F= 
  7*4210 
  

  

  The 
  numerous 
  observations 
  for 
  time 
  at 
  the 
  different 
  stations 
  have 
  not 
  

   been 
  given, 
  as 
  of 
  no 
  interest. 
  

  

  I 
  arrived 
  in 
  INamaqualand 
  on 
  April 
  9, 
  by 
  the 
  Union 
  steamship 
  

   •jNainaqua,' 
  Captain 
  Barker, 
  reached 
  Port 
  Nolloth, 
  on 
  my 
  return, 
  on 
  

   the 
  evening 
  of 
  Wednesday, 
  April 
  29, 
  but 
  did 
  not 
  sail 
  until 
  Wednesday, 
  

   May 
  6, 
  reaching 
  the 
  observatory 
  on 
  Saturday, 
  May 
  9. 
  

  

  XVI. 
  " 
  On 
  the 
  Proportions 
  of 
  the 
  several 
  Lobes 
  of 
  the 
  Cerebrum 
  

   in 
  Man 
  and 
  in 
  certain 
  of 
  the 
  higher 
  Vertebrata,, 
  and 
  on 
  an 
  

   attempt 
  to 
  explain 
  some 
  of 
  the 
  Asymmetry 
  of 
  the 
  Cerebral 
  Con- 
  

   volutions 
  in 
  Man/' 
  By 
  John 
  Marshall, 
  F.R.S., 
  F.R.C.S.E., 
  

   Professor 
  of 
  Surgery, 
  University 
  College, 
  London, 
  &c. 
  Re- 
  

   ceived 
  June 
  17, 
  1875. 
  

  

  1. 
  I 
  desire 
  to 
  communicate 
  to 
  the 
  Royal 
  Society 
  the 
  fact 
  that 
  I 
  have, 
  

   by 
  severing 
  the 
  cerebral 
  hemispheres 
  in 
  certain 
  definite 
  directions 
  in 
  

   Man, 
  and 
  also 
  in 
  some 
  of 
  the 
  higher 
  Vertebrata, 
  and 
  by 
  then 
  weighing 
  

   the 
  separated 
  portions, 
  not 
  only 
  arrived 
  at 
  some 
  interesting 
  and 
  im- 
  

   portant 
  results 
  as 
  to 
  the 
  relative 
  size 
  of 
  those 
  portions 
  in 
  different 
  

   animals 
  and 
  in 
  Man, 
  but 
  I 
  am 
  enabled 
  to 
  state 
  that 
  this 
  method, 
  applied 
  

   to 
  the 
  brains 
  of 
  individuals 
  of 
  different 
  race, 
  sex, 
  age, 
  education, 
  and 
  

   occupation, 
  seems 
  likely 
  to 
  furnish 
  a 
  means 
  of 
  investigating 
  individual 
  

   peculiarities 
  in 
  the 
  human 
  cerebrum. 
  

  

  I 
  p±^opose 
  shortly 
  to 
  communicate 
  my 
  results 
  to 
  the 
  Society. 
  

  

  2. 
  I 
  have 
  likewise 
  made 
  numerous 
  observations 
  on 
  the 
  convolutions 
  

   of 
  the 
  human 
  brain 
  with 
  the 
  view 
  of 
  explaining 
  then 
  symmetry 
  in 
  certain 
  

   regions, 
  and 
  their 
  asymmetry 
  in 
  others. 
  In 
  endeavouring 
  to 
  trace 
  more 
  

   particularly 
  the 
  causes 
  of 
  the 
  asymmetry 
  of 
  the 
  convolutions 
  which 
  pre- 
  

   vails 
  in 
  Man, 
  I 
  have 
  been 
  led 
  to 
  believe 
  that 
  some, 
  at 
  least, 
  of 
  this 
  is 
  

   due 
  to 
  the 
  right-handedness 
  of 
  Man. 
  

  

  I 
  find, 
  on 
  studying 
  a 
  large 
  number 
  of 
  human 
  cerebra, 
  that 
  there 
  are 
  

   stronger 
  evidences 
  of 
  essential 
  asymmetry, 
  as 
  distinguished 
  from 
  what 
  I 
  

   would 
  term 
  non-essential 
  asymmetry, 
  in 
  the 
  immediate 
  neighbourhood 
  of 
  

   the 
  left 
  fissure 
  of 
  Rolando, 
  and 
  next 
  to 
  this 
  part 
  in 
  the 
  right 
  parietal 
  

   lobule. 
  

  

  There 
  are 
  certain 
  secondary 
  essential 
  asymmetrical 
  conditions 
  which 
  

   may 
  be 
  pointed 
  out, 
  and 
  besides 
  this 
  many 
  non-essential 
  and 
  very 
  

   variable 
  ones. 
  

  

  