﻿Mechanism 
  of 
  the 
  Bill 
  in 
  Birds. 
  361 
  

  

  XXXIII. 
  — 
  On 
  a 
  Point 
  in 
  the 
  Mechanism 
  of 
  the 
  Bill 
  in 
  Birds. 
  

   By 
  W. 
  P. 
  Pycraft, 
  Anatomical 
  Department, 
  University 
  

   Museum, 
  Oxford. 
  

  

  It 
  is 
  a 
  well-known 
  fact 
  that 
  very 
  many 
  birds 
  possess 
  the 
  

   power 
  of 
  raising" 
  the 
  upper 
  jaw, 
  though 
  in 
  varying 
  degrees 
  of 
  

   freedom, 
  depending 
  upon 
  its 
  general 
  conformation 
  and 
  upon 
  

   the 
  nature 
  of 
  the 
  articulation 
  with 
  the 
  frontal 
  bones. 
  Thus 
  

   in 
  the 
  Parrots, 
  Avhich 
  are 
  remarkable 
  for 
  the 
  facility 
  with 
  

   which 
  the 
  upper 
  jaw 
  is 
  raised, 
  we 
  have 
  a 
  fronto-nasal 
  hinge, 
  

   whilst, 
  more 
  generally, 
  the 
  same 
  end 
  is 
  obtained 
  by 
  slender 
  

   and 
  flexible 
  preraaxillary 
  nasal 
  processes, 
  which 
  overlap 
  

   the 
  frontal 
  bones. 
  

  

  In 
  every 
  case 
  w^iich 
  has 
  been 
  recorded 
  up 
  till 
  now, 
  how- 
  

   ever, 
  the 
  upper 
  jaw 
  has 
  been 
  moved 
  bodily, 
  but 
  in 
  the 
  case 
  

   I 
  am 
  about 
  to 
  describe 
  the 
  distal 
  extremity 
  only 
  is 
  raised. 
  

  

  Some 
  two 
  years 
  ago, 
  a 
  live 
  Dunlin 
  [Tringa 
  alpina, 
  Linn.) 
  

   was 
  given 
  me, 
  which 
  I 
  endeavoured 
  to 
  keep 
  as 
  long 
  as 
  possible, 
  

   in 
  the 
  hope 
  of 
  learning 
  something 
  of 
  its 
  life-history. 
  In 
  

   this 
  I 
  was 
  only 
  partially 
  successful, 
  for 
  the 
  bird 
  lived 
  but 
  a 
  

   few 
  days 
  — 
  during 
  which 
  time, 
  however, 
  I 
  imagined, 
  on 
  two 
  

   or 
  three 
  occasions, 
  that 
  I 
  detected 
  an 
  upward 
  turning 
  of 
  the 
  

   tip 
  of 
  the 
  upper 
  jaw, 
  apparently 
  accompanied 
  by 
  a 
  very 
  

   human-like 
  gape; 
  nevertheless, 
  owing 
  to 
  the 
  speed 
  and 
  

   unexpectedness 
  of 
  the 
  action, 
  I 
  failed 
  to 
  satisfy 
  myself 
  that 
  

   I 
  was 
  not 
  mistaken. 
  

  

  During 
  the 
  Christmas 
  holidays 
  I 
  paid 
  a 
  short 
  visit 
  with 
  

   my 
  brother 
  to 
  Breydon 
  Water, 
  Great 
  Yarmouth, 
  for 
  the 
  

   purpose 
  of 
  obtaining 
  specimens. 
  Dunlins 
  were 
  exceedingly^ 
  

   numerous 
  and 
  we 
  bagged 
  several 
  ; 
  amongst 
  these 
  were 
  two 
  

   wounded 
  birds, 
  which 
  I 
  undertook 
  to 
  kill, 
  hoping 
  that 
  I 
  

   might 
  now 
  set 
  at 
  rest 
  my 
  suspicions 
  of 
  other 
  days. 
  

  

  In 
  both 
  cases, 
  in 
  the 
  spasmodic 
  contractions 
  preceding 
  

   death, 
  the 
  tip 
  of 
  the 
  beak 
  was 
  distinctly 
  curved 
  upwards 
  ; 
  

   but, 
  in 
  the 
  anxiety 
  of 
  watching 
  for 
  this 
  particular 
  movement, 
  

   I 
  quite 
  forgot 
  to 
  notice 
  whether 
  it 
  was 
  correlated 
  with 
  the 
  

   opening 
  of 
  the 
  mouth 
  or 
  not, 
  although 
  in 
  all 
  probability 
  

   it 
  was. 
  

  

  