ME.  J.  L.  CLAEKE  ON  THE  INTIMATE  STEUCTUEE  OF  THE  BEAIN. 
257 
Transverse  section  of  the  medulla  oblongata  of  the  Sheep,  at  the  lowest  roots 
of  the  hypoglossal  nerves  z^z\ — spinal-accessory  nerve  proceeding  through 
the  network  into  which  the  lateral  grey  substance  is  resolved. 
Similar  section  through  the  lower  part  of  the  protuberance  i (tig.  8): — 7,  ante- 
rior pyramids  enclosing  the  olivary  bodies. 
PLATE  XIII. 
Fig.  II.  Transverse  section  of  the  human  medulla  oblongata  at  the  point  of  the  ante- 
rior pyramids,  showing  the  commencement  of  the  decussation : — 7,  i,  anterior 
columns.  The  anterior  cornua  are  pierced  by  numerous  longitudinal  bundles, 
amongst  which  the  nerve-cells  are  scattered.  A network  of  fibres  from  the 
lateral  grey  substance  proceeds  outwards  between  bundles  of  the  lateral 
column : f'"^  fibres  of  the  posterior  roots  running  backwards  through  the  postc'- 
rior  column. 
Fig.  12.  Oblique  section  from  before  backwards,  through  the  loAver  part  of  the  anterior 
pyramids,  in  the  plane  of  the  decussating  fibres  which  proceed  from  the 
lateral  columns : — «,  commencement  of  the  restiform  ganglion ; b,  commence- 
ment of  the  post-pyramidal  ganglion ; z,  z,  anterior  pyramids. 
Fig.  15.  Transverse  section  of  the  medulla  oblongata  of  the  Cat,  through  the  broadest 
part  of  the  decussation : — -f,  f,  grey  tubercles  of  Eolando. 
Fig.  16.  A similar  section  from  the  medulla  oblongata  of  the  Dog: — b,  posterior  pyra- 
mids. 
Fig.  17.  Similar  section  from  the  Guinea  Pig. 
Fig.  18.  Transverse  section  of  the  medulla  oblongata  of  the  domestic  Fowl: — g'\  spinal- 
accessory  nerve. 
Fig.  20.  Cells  from  the  humdiOi post-pyramidal  ganglion',  magnified  420  diameters. 
Fig.  21.  Cells  from  the  human  restiform  ganglion-,  magnified  420  diameters. 
Fig.  22.  Cells  from  the  human  olivary  body,  magnified  420  diameters. 
Fig.  13. 
Fig.  14. 
PLATE  XIV. 
Fig.  23.  A transverse  section  of  the  human  medulla  oblongata,  immediately  below  the 
olivary  bodies : — a,  a,  restiform  bodies  containing  the  restiform  ganglia,  or 
grey  substance  developed  from  the  back  of  the  cervix  cornus  posterioris ; 
b,  b,  posterior  pyramids,  containing  the  post-pyramidal  ganglia ; f the  grey 
tubercle  of  Eolando,  or  expanded  extremity  of  the  posterior  cornu — the  caput 
cornus.  At  its  root,  d,  fibres  proceeding  from  the  central  part  of  the  posterior 
grey  substance  are  mixed  in  an  intricate  plexus,  which  encloses  in  its  meshes 
numerous  longitudinal  bundles  (represented  by  the  dark  spots),  and  contains 
a number  of  cells  of  different  shapes  (but  repre.sented  by  the  small  circles), 
MDCCCLVIII.  2 M 
