﻿682 
  Recently 
  published 
  Ornitholoyical 
  Works. 
  

  

  their 
  pure 
  and 
  excellent 
  diction 
  and 
  the 
  many 
  strange 
  fancies 
  

   involved 
  in 
  them. 
  But 
  in 
  spite 
  of 
  Mr. 
  Hudson's 
  admiration 
  

   (see 
  p. 
  76), 
  we 
  must 
  continue 
  to 
  regard 
  the 
  Greenfinch 
  as 
  

   an 
  emphatically 
  " 
  dull 
  " 
  bird, 
  and 
  to 
  prefer 
  the 
  Uvely 
  Wood- 
  

   Pigeon, 
  which 
  he 
  stigmatizes, 
  most 
  unfairly 
  in 
  our 
  opinion, 
  

   as 
  a 
  "dismal 
  croaker 
  '^ 
  (p. 
  101). 
  

  

  95. 
  Keeler 
  on 
  the 
  Colour's 
  of 
  Birds. 
  

  

  [Evolution 
  of 
  the 
  Colours 
  of 
  North- 
  American 
  Land 
  Birds. 
  By 
  Charles 
  

   A. 
  Keeler. 
  8vo. 
  San 
  Francisco 
  : 
  1893. 
  Pp. 
  361 
  ; 
  17 
  plates. 
  Occasional 
  

   Papers 
  of 
  the 
  Californian 
  Ac. 
  of 
  Sci. 
  no. 
  iii.] 
  

  

  This 
  is, 
  no 
  doubt, 
  a 
  valuable 
  contribution 
  towards 
  our 
  

  

  knowledge 
  of 
  an 
  obscure 
  and 
  little-discussed 
  subject, 
  "written 
  

  

  more 
  with 
  the 
  hope 
  of 
  stimulating 
  thought 
  and 
  inciting 
  

  

  research 
  '^ 
  than 
  with 
  the 
  expectation 
  of 
  reaching 
  definite 
  

  

  results. 
  The 
  problems, 
  indeed, 
  of 
  sexual 
  coloration 
  are, 
  in 
  

  

  our 
  opinion, 
  hardly 
  ripe 
  for 
  settlement 
  ; 
  here, 
  as 
  elsewhere 
  

  

  in 
  matters 
  relating 
  to 
  animal 
  coloration, 
  the 
  facts 
  have 
  been 
  

  

  altogether 
  outstripped 
  by 
  the 
  theories. 
  It 
  is, 
  however, 
  most 
  

  

  useful 
  to 
  do 
  as 
  Mr. 
  Keeler 
  has 
  done 
  — 
  to 
  give 
  a 
  general 
  

  

  account 
  of 
  the 
  facts 
  and 
  theories 
  relating 
  to 
  a 
  particular 
  

  

  group. 
  In 
  these 
  days 
  of 
  necessary 
  specialism 
  no 
  one 
  head 
  

  

  can 
  possibly 
  carry 
  enough 
  facts 
  to 
  give 
  an 
  impartial 
  and 
  

  

  thoroughly 
  well-informed 
  survey 
  of 
  the 
  colour-phenomena 
  

  

  of 
  the 
  entire 
  animal 
  kingdom. 
  The 
  whole 
  subject, 
  too, 
  has 
  

  

  been 
  approached 
  more 
  from 
  the 
  speculative 
  and 
  less 
  from 
  

  

  the 
  physiological 
  side 
  than 
  ought 
  to 
  have 
  been 
  the 
  case. 
  

  

  Dr. 
  Sauermann''s 
  remarkable 
  experiments 
  (duly 
  quoted 
  by 
  

  

  our 
  author) 
  on 
  feeding 
  white 
  fowls 
  with 
  the 
  colouring-matter 
  

  

  of 
  cayenne 
  pepper 
  showed 
  conclusively 
  that 
  the 
  colour 
  was 
  

  

  not 
  uniformly 
  absorbed 
  by 
  the 
  feathers, 
  but 
  that 
  there 
  was 
  

  

  a 
  distinct 
  selective 
  process, 
  certain 
  parts 
  of 
  the 
  body 
  only 
  

  

  becoming 
  tinged. 
  This 
  naturally 
  suggests 
  that 
  other 
  factors 
  

  

  than 
  natural 
  selection 
  may 
  operate 
  in 
  producing 
  patches 
  

  

  and 
  spots 
  in 
  other 
  birds, 
  which 
  have 
  been 
  hitherto 
  set 
  down 
  

  

  to 
  " 
  protective 
  resemblance,^'' 
  " 
  mimicry,'^ 
  &c. 
  The 
  onus 
  

  

  probandi, 
  moreover, 
  does 
  not 
  entirely 
  lie 
  with 
  those 
  who 
  

  

  look 
  with 
  more 
  or 
  less 
  concealed 
  scepticism 
  upon 
  the 
  appli- 
  

  

  