﻿370 
  Swifts 
  and 
  Humming-birds. 
  

  

  in 
  the 
  transition 
  from 
  the 
  humerus 
  of 
  the 
  Goatsucker 
  to 
  that 
  

   of 
  the 
  Huraming-birdj 
  and 
  I 
  fail^ 
  in 
  any 
  of 
  them^ 
  to 
  see 
  any 
  

   striking 
  morphological 
  resemblance 
  to 
  the 
  humerus 
  of 
  a 
  

   Swallow. 
  It 
  must 
  be 
  steadily 
  borne 
  in 
  mind 
  that^ 
  as 
  the 
  

   Humming-bird 
  is 
  without 
  a 
  rival 
  in 
  its 
  power 
  of 
  aerial 
  

   evolution^ 
  we 
  must 
  expect 
  to 
  find 
  such 
  mechanical 
  and 
  

   adaptive 
  modifications 
  in 
  its 
  mechanism 
  as 
  exist 
  in 
  no 
  other 
  

   bird, 
  and 
  we 
  must 
  not 
  confound 
  physiological 
  modifications 
  

   with 
  morphological 
  resemblances. 
  

  

  The 
  comparison 
  of 
  the 
  furcula 
  of 
  the 
  Humming-bird 
  to 
  

   that 
  of 
  the 
  Albatross, 
  coupled 
  with 
  the 
  remark 
  that 
  these 
  

   birds, 
  as 
  well 
  as 
  the 
  Swifts, 
  are 
  great 
  fliers, 
  would 
  lead 
  one 
  

   to 
  infer 
  that 
  the 
  similarity 
  was 
  due 
  to 
  physiological 
  

   adaption. 
  This, 
  however, 
  can 
  scarcely 
  be 
  the 
  case, 
  since 
  

   there 
  are 
  no 
  two 
  birds 
  whose 
  mode 
  of 
  flight 
  is 
  more 
  at 
  

   variance 
  than 
  those 
  named 
  above. 
  In 
  the 
  case 
  of 
  the 
  

   Humming-bird, 
  too, 
  the 
  furcula 
  is 
  not 
  functional 
  ; 
  the 
  bird 
  

   could 
  get 
  along 
  without 
  it, 
  while 
  in 
  the 
  Albatross 
  its 
  power 
  

   to 
  brace 
  the 
  wings 
  apart 
  is 
  but 
  trifling. 
  The 
  resemblance 
  is 
  

   apparently 
  due 
  to 
  the 
  fact 
  that 
  in 
  many 
  points 
  these 
  birds 
  

   are 
  both 
  generalized 
  and 
  the 
  furcula 
  morphologically 
  low, 
  

   its 
  pattern 
  being 
  in 
  fact 
  suggestive 
  of 
  what 
  we 
  see 
  in 
  many 
  

   lizards. 
  

  

  There 
  are 
  some 
  points 
  in 
  the 
  Humming-bird^s 
  wing 
  that 
  

   are 
  structurally 
  more 
  Passerine 
  than 
  what 
  we 
  find 
  in 
  similar 
  

   portions 
  of 
  the 
  wing 
  of 
  the 
  Swift, 
  and 
  this, 
  in 
  conjunction 
  

   with 
  Professor 
  Stewart^s 
  observations 
  on 
  the 
  palate, 
  will 
  bring 
  

   the 
  Trochili 
  a 
  step 
  or 
  two 
  nearer 
  the 
  great 
  Passerine 
  

   assemblage 
  than 
  they 
  have 
  usually 
  been 
  placed. 
  

  

  There 
  are 
  other 
  points 
  that 
  I 
  would 
  like 
  to 
  discuss, 
  but 
  

   this 
  paper 
  is 
  already 
  rather 
  long. 
  I 
  would 
  like 
  to 
  acknowledge 
  

   my 
  indebtedness 
  to 
  Dr. 
  Sclater 
  for 
  specimens 
  of 
  Cypseli, 
  and 
  

   to 
  express 
  my 
  regret 
  that 
  untoward 
  circumstances 
  have 
  

   prevented 
  me 
  from 
  completing 
  my 
  examination 
  of 
  them. 
  

  

  In 
  conclusion, 
  I 
  wish 
  to 
  say 
  that 
  these 
  remarks 
  are 
  not 
  put 
  

   forward 
  in 
  any 
  spirit 
  of 
  captious 
  criticism. 
  No 
  one 
  admires 
  

   Dr. 
  Shufeldt^s 
  enthusiasm, 
  or 
  envies 
  him 
  his 
  power 
  of 
  

   continued 
  application, 
  more 
  than 
  myself, 
  nor 
  do 
  many 
  better 
  

  

  