﻿362 
  

  

  Mr. 
  W. 
  P. 
  Pycraft 
  on 
  the 
  Mechanism 
  

  

  Ou 
  my 
  return 
  to 
  Oxford, 
  I 
  dissected 
  the 
  head 
  of 
  one 
  of 
  

   these 
  birds 
  and 
  found, 
  as 
  I 
  expected, 
  that 
  the 
  movement 
  

   was 
  due 
  — 
  and 
  I 
  think 
  mainly 
  — 
  to 
  the 
  action 
  of 
  the 
  muscles 
  

   attached 
  to 
  the 
  quadrate 
  and 
  pterygoid 
  bones. 
  1 
  have 
  no 
  

   doubt 
  that 
  the 
  majority 
  of 
  the 
  readers 
  of 
  'The 
  Ibis' 
  will 
  

   readily 
  call 
  to 
  mind 
  the 
  muscles 
  to 
  which 
  I 
  refer, 
  but 
  for 
  the 
  

   sake 
  of 
  those 
  who 
  may 
  not 
  — 
  for 
  we 
  are 
  not 
  all 
  ornitho- 
  

   tomists 
  — 
  I 
  may 
  perhaps 
  be 
  excused 
  if 
  I 
  briefly 
  describe 
  

   them. 
  

  

  P.m. 
  

  

  View 
  of 
  the 
  right 
  side 
  of 
  the 
  head 
  of 
  a 
  Dunlin 
  {Tringa 
  alpina, 
  L.), 
  showing, 
  

   by 
  the 
  dotted 
  lines, 
  how 
  the 
  bill 
  curves 
  upwards 
  as 
  a 
  result 
  of 
  the 
  

   contraction 
  of 
  the 
  muscles 
  described 
  on 
  p. 
  363. 
  Only 
  one 
  of 
  these 
  

   muscles 
  is 
  seen, 
  the 
  other 
  being 
  concealed 
  by 
  the 
  quadrate 
  bone 
  and 
  

   the 
  entotympanicus. 
  

  

  E. 
  Entotympanicus 
  ; 
  Q. 
  Quadrate 
  ; 
  M. 
  Mandible 
  cut 
  short 
  ; 
  P.m. 
  Pre- 
  

   maxilla 
  ; 
  PI. 
  Palatine. 
  

  

  These 
  muscles 
  are 
  two 
  in 
  number. 
  The 
  one 
  (E.) 
  arises 
  

   from 
  the 
  basisphenoid 
  below 
  the 
  optic 
  foramen, 
  and 
  is 
  inserted 
  

   into 
  the 
  upper 
  border 
  of 
  the 
  orbital 
  process 
  of 
  the 
  quadrate 
  

   bone 
  (Q.) 
  ; 
  the 
  other 
  (which 
  is 
  not 
  shown 
  in 
  the 
  figure) 
  

   arises 
  from 
  the 
  inferior 
  border 
  of 
  the 
  orbital 
  septum 
  and 
  the 
  

   rostrum 
  of 
  the 
  basisphenoid, 
  and, 
  its 
  fibres 
  converging, 
  

   is 
  inserted, 
  as 
  a 
  slender 
  tendon, 
  into 
  the 
  upper 
  border 
  of 
  

   the 
  proximal 
  end 
  of 
  the 
  pterygoid. 
  

  

  These 
  two 
  muscles 
  are 
  described 
  by 
  Dr. 
  Gadow 
  * 
  as 
  a 
  part 
  

   of 
  the 
  musculus 
  temporalis, 
  which, 
  according 
  to 
  this 
  author, 
  

   is 
  composed 
  of 
  five 
  parts, 
  to 
  the 
  fifth 
  of 
  which 
  the 
  muscles 
  in 
  

   question 
  belong 
  ; 
  further 
  than 
  this, 
  however, 
  they 
  are 
  not 
  

  

  * 
  See 
  works 
  of 
  reference 
  cited 
  at 
  the 
  end 
  of 
  this 
  paper. 
  

  

  