﻿Sioifts 
  and 
  Humming 
  -birds. 
  

  

  89 
  

  

  utterly 
  different 
  in 
  tlie 
  two 
  suborders, 
  that 
  comparison 
  here 
  would 
  simply 
  

   mean 
  to 
  occupy 
  valuable 
  space 
  that 
  I 
  prefer 
  to 
  use 
  in 
  making 
  comparisons 
  

   in 
  structure. 
  Let 
  us 
  remember, 
  however, 
  that 
  Dr. 
  Coues 
  notes 
  in 
  the 
  

   case 
  of 
  Swallows 
  that 
  " 
  formerly 
  they 
  all 
  bred 
  on 
  cliffs, 
  in 
  banks, 
  in 
  

   hollows 
  of 
  trees, 
  and 
  similar 
  places, 
  and 
  many 
  do 
  so 
  still 
  " 
  (o^j. 
  cit. 
  p. 
  321 
  ) 
  ; 
  

   and 
  some 
  Swallows, 
  too, 
  do 
  lay 
  xvhite 
  eggs, 
  and 
  in 
  number 
  these 
  are 
  more 
  

   apt 
  to 
  agree 
  with 
  the 
  Cypseli, 
  I 
  think, 
  than 
  with 
  the 
  Trochili 
  ! 
  

  

  A 
  few 
  more 
  points 
  are 
  as 
  follows 
  : 
  — 
  

  

  Cypskli. 
  

  

  8. 
  Sexes 
  alike 
  (as 
  is 
  generally 
  the 
  

   case 
  in 
  the 
  Swallows 
  ?) 
  

  

  9. 
  Birds 
  all 
  of 
  moderate 
  size 
  (as 
  

   is 
  the 
  case 
  in 
  the 
  Swallows). 
  

  

  Trochili. 
  

  

  8. 
  Sexes 
  markedly 
  unlike 
  (with 
  

   but 
  one 
  or 
  two 
  rare 
  exceptions 
  ?). 
  

  

  9. 
  Birds 
  (with 
  but 
  one 
  or 
  two 
  

   exceptions) 
  all 
  of 
  the 
  most 
  diminu- 
  

   tive 
  size 
  to 
  be 
  found 
  in 
  the 
  class. 
  

  

  10. 
  Coloration 
  extremely 
  plain 
  ; 
  

   plumes, 
  crests, 
  gorgets, 
  remarkable 
  

   variation 
  in 
  tails 
  never 
  present. 
  

   (Agreeing 
  in 
  the 
  main 
  with 
  Swal- 
  

   lows.) 
  

  

  11. 
  " 
  One 
  of 
  the 
  most 
  remarkable 
  

   points 
  in 
  the 
  structure 
  of 
  the 
  Cyp- 
  

   selidaj 
  is 
  the 
  great 
  development 
  of 
  

   the 
  salivary 
  glands 
  " 
  (Sclater). 
  

  

  12. 
  General 
  form 
  of 
  the 
  plucked 
  

   body 
  in 
  some 
  species 
  like 
  the 
  

   Swallows. 
  

  

  13. 
  Pterylosis 
  is 
  but 
  a 
  departure, 
  

   in 
  most 
  species, 
  from 
  the 
  common 
  

   passerine 
  pattern 
  as 
  seen 
  in 
  the 
  

   Swallows. 
  

  

  10. 
  Coloration 
  among 
  the 
  mos^t 
  

   brilliant 
  of 
  all 
  birds 
  ; 
  as 
  a 
  rule, 
  the 
  

   presence 
  of 
  freaks 
  in 
  feather-orna- 
  

   mentation 
  is 
  frequent 
  and 
  extrava- 
  

   gant 
  in 
  form 
  and 
  colour. 
  

  

  11. 
  Salivary 
  glands 
  not 
  remark- 
  

   ably 
  or 
  even 
  abnormally 
  developed. 
  

  

  12. 
  General 
  form 
  of 
  the 
  plucked 
  

   body 
  in 
  none 
  of 
  the 
  species 
  ever 
  

   having 
  any 
  resemblance 
  to 
  that 
  of 
  

   the 
  Swallows. 
  

  

  13. 
  " 
  Pterylosis 
  is 
  characteristic 
  " 
  

   (Coues). 
  Differs 
  in 
  a 
  number 
  of 
  

   particulars 
  from 
  what 
  we 
  find 
  in 
  

   either 
  Swifts 
  or 
  Swallows. 
  

  

  Dr. 
  Sclater 
  has 
  said 
  of 
  NitzscVs 
  ' 
  Pterylography,' 
  in 
  

   his 
  preface 
  to 
  the 
  English 
  translation^ 
  '' 
  that 
  it 
  is 
  one 
  of 
  the 
  

   most 
  valuable 
  and 
  suggestive 
  works 
  on 
  pure 
  ornithology 
  ever 
  

   published.^' 
  And 
  until 
  such 
  labours 
  are 
  followed 
  up 
  and 
  

   fully 
  accomplished, 
  " 
  we 
  can 
  never 
  hope 
  to 
  arrive 
  at 
  a 
  correct 
  

   knowledge 
  of 
  the 
  affinities 
  of 
  this 
  very 
  difficult 
  class 
  of 
  Ver- 
  

   tebrates 
  '^ 
  [Birds]. 
  Yet 
  Nitzsch, 
  in 
  that 
  work 
  (p. 
  86), 
  in 
  

   speaking 
  of 
  the 
  classification 
  and 
  pterylography 
  of 
  the 
  

   " 
  Macrochires/' 
  was 
  compelled 
  to 
  admit 
  that^ 
  — 
  '' 
  In 
  this 
  

   family 
  I 
  place 
  the 
  two 
  genera 
  Cypselus 
  and 
  Trochilus, 
  whicb^ 
  

  

  