﻿THE 
  5I1DDLE 
  EAR 
  AND 
  COLUMELLA 
  OE 
  BIRDS. 
  

  

  15 
  

  

  to 
  the 
  tympanic 
  ineuibrauej 
  na-inely 
  lying" 
  just 
  internal 
  to 
  it 
  

   and 
  external 
  to 
  the 
  extra-col 
  umella, 
  save 
  that 
  at 
  the 
  point 
  

   where 
  it 
  crosses 
  the 
  neck 
  Avhich 
  unites 
  the 
  supra- 
  aud 
  extra- 
  

   stapedials 
  it 
  pierces 
  the 
  cartilage 
  superficially. 
  

  

  supraustap 
  ^ 
  

  

  Fig. 
  3. 
  — 
  Right 
  ear 
  of 
  Columba. 
  Upper 
  half 
  of 
  tympanic 
  membrane 
  

   deflected 
  to 
  show 
  the 
  structures 
  upon 
  its 
  otlier 
  side. 
  siap. 
  Stapes, 
  swpra 
  

   stop. 
  Supra-stapedial. 
  extra 
  stap. 
  Extra-stapedial. 
  pit. 
  Platner's 
  ligament. 
  

   VII. 
  Seventh 
  nerve, 
  ck. 
  Chorda 
  tympani, 
  X 
  Point 
  at 
  which 
  chorda 
  tympani 
  

   comes 
  off 
  in 
  Gallus. 
  tt/m. 
  Tympanum, 
  (in. 
  Quadrate. 
  For 
  this 
  drawing 
  I 
  

   am 
  much 
  indebted 
  to 
  Mr. 
  Darbisliire. 
  

  

  Having 
  traversed 
  the 
  extra-col 
  umella, 
  the 
  chorda 
  joins 
  

   Platner's 
  ligament 
  and 
  crosses 
  the 
  tympanic 
  cavity 
  in 
  com- 
  

   pany 
  with 
  it, 
  so 
  gaining 
  the 
  posterior 
  face 
  of 
  the 
  quadrate. 
  

   This 
  course 
  of 
  the 
  chorda 
  tympani 
  has 
  been 
  confirmed 
  by 
  

   means 
  of 
  serial 
  sections 
  in 
  a 
  late 
  embryo 
  of 
  the 
  starling. 
  

  

  The 
  essential 
  difference 
  between 
  the 
  relations 
  of 
  the 
  chorda 
  

  

  