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XIV.  Researches  cm  the  Intimate  Structure  of  the  Brain,  Human  and  Comparative. — 
First  Series.  On  the  Structure  of  the  Medulla  oblongata.  By  J.  Lockhaet  Clarke, 
Esq.,  F.R.S. 
Received  June  18, — Read  June  18,  1857. 
(1.)  Galejs^  believed  that  the  medulla  spinalis  commences  as  high  up  as  the  lower  border 
of  the  pons  Varolii.  This,  like  nearly  every  other,  opinion  of  the  Greek  anatomist  was 
adopted  by  all  his  successors  until  the  time  of  Sylvius  and  Vesalius.  Sylvius  traced 
the  origin  of  the  spinal  chord  from  the  whole  base  of  the  brain  ^ ; Vesalius,  only  from 
the  corpora  quadrigemina'^.  Columbus^,  Varolius^  Spigelius^  Laurentius®,  Riolanus^ 
Highmore®,  described  it  as  arising  by  two  roots, — one  large,  from  the  entire  base  of  the 
brain ; the  other  small,  from  the  cerebellum.  But  Piccolhomini  introduced  a better 
description  of  these  parts,  by  restricting  the  term  “medulla  spinalis'"  to  the  contents  of 
the  spinal  column ; while  to  the  whole  intra-cranial  prolongation  along  the  base  of  the 
brain,  he  applied  the  term  “medulla  oblongata"^,  which  has  been  retained  to  the  pre- 
sent day,  though  many  anatomists  have  dilfered  with  regard  to  the  number  of  parts  it 
has  been  supposed  to  comprehend.  According  to  Willis*”,  it  includes  the  whole  base 
of  the  brain,  from  the  corpora  striata — which  he  called  “medullse  oblongatee  apices” — 
to  t\ie  foramen  magnum.  The  same  view  was  adopted  by  Vieussens  **,  Wikslow*^,  and 
others ; while  Rolando  employed  the  term  in  a more  restricted  sense ; and  Ridley 
who  did  the  same,  substituted  for  it  the  term  “isthmus,”  and  Chaussier*®  that  of 
“ mesocephale,”  which  included  the  pons,  tubercula  quadrigemina,  with  the  superior 
peduncles  of  the  cerebellum,  and  not  the  pons  only,  as  sometimes  stated.  Flourens’®', 
again,  on  the  ground  of  his  experimental  inquiries, — which  led  him  to  conclude  that  the 
seat  of  excitability  begins  or  ends  with  the  corpora  quadrigemina, — limits  the  medulla 
oblongata  between  these  bodies  and  the  eighth  pair  of  nerves.  In  this  country  the 
' Isagoge  (1556),  Hb.  iii.  cap.  xxii.  ^ De  Humani  corporis  Fabrica,  lib.  iv.  and  vii. 
* De  Re  Anatomica,  p.  367  (1562).  ^ De  Nervis  Opticis,  p.  128. 
De  Humani  Corporis  Fabrica,  p.  295  (1627).  ® Historia  Anatomica,  p.  529  (1600). 
^ Anthropograpbia,  Hb.  v.  (1618). 
® Corp.  Hum.  Disquisit.  Anat.  lib.  i.  (1651). 
® Anatomicse  Prselectiones,  bb.  5.  Lect.  iii.  and  v.  (1586).  The  whole  of  the  description  is  excellent,  and 
very  superior  to  that  of  any  previous  anatomist. 
Cerebri  Anatome,  cap.  ti.  (1664).  '*  Neurographia  Universalis  (1684). 
Exposition  Anatomique,  Traite  de  la  Teste,  p.  126  (1695). 
**  Recherches  Anatomiques  sur  la  Moelle  allongee. 
Anatomy  of  the  Brain,  p.  126  (1695).  De  TEncephale,  p.  106. 
Recherches  Experimentales  sur  les  Proprietes  et  les  Fonctions  du  Systeme  Nerveux,  pp.  21  and  239. 
