﻿S54 
  Transactions. 
  — 
  Zoology. 
  

  

  a 
  number 
  together 
  in 
  time 
  of 
  danger. 
  Tliey 
  are 
  very 
  plentiful 
  and 
  very 
  

   pugnacious, 
  frequently 
  driving 
  aAvay 
  crows 
  and 
  even 
  hawks, 
  which 
  perch 
  

   on 
  a 
  tree 
  where 
  a 
  few 
  of 
  them 
  are 
  assembled. 
  It 
  is 
  very 
  probable, 
  there- 
  

   fore, 
  that 
  the 
  smaller 
  birds 
  of 
  prey 
  have 
  learnt 
  to 
  respect 
  these 
  birds, 
  and 
  

   leave 
  them 
  alone, 
  and 
  it 
  may 
  thus 
  be 
  a 
  great 
  advantage 
  for 
  the 
  weaker 
  and 
  

   less 
  courageous 
  Mimetas 
  to 
  be 
  mistaken 
  for 
  them. 
  This 
  being 
  the 
  case, 
  

   the 
  laws 
  of 
  Variation 
  and 
  Survival 
  of 
  the 
  fittest, 
  will 
  suffice 
  to 
  explain 
  how 
  

   the 
  resemblance 
  has 
  been 
  brought 
  about, 
  without 
  supposing 
  any 
  voluntary 
  

   action 
  on 
  the 
  part 
  of 
  the 
  birds 
  themselves 
  ; 
  and 
  those 
  who 
  have 
  read 
  Mr. 
  

   Darwin's 
  ' 
  Origin 
  of 
  Species 
  ' 
  will 
  have 
  no 
  difficulty 
  in 
  comprehending 
  the 
  

   whole 
  process." 
  

  

  Among 
  the 
  many 
  minor 
  instances 
  that 
  have 
  attracted 
  notice, 
  the 
  

   English 
  cuckoo 
  (Cacabus 
  canorus) 
  is 
  supposed 
  to 
  derive 
  protection 
  from 
  the 
  

   resemblance 
  of 
  its 
  markings 
  to 
  those 
  of 
  the 
  sparrow-hawk 
  fAccipiter 
  vAsus), 
  

   but 
  the 
  resemblance 
  is 
  far 
  more 
  strikmg 
  between 
  our 
  long-tailed 
  cuckoo 
  

   ( 
  Eudynamis 
  taitcnsis) 
  and 
  a 
  North 
  American 
  species 
  of 
  hawk 
  ( 
  Accvpiter 
  

   couperi). 
  In 
  the 
  fine 
  specimens 
  of 
  the 
  former 
  which 
  I 
  exhibit 
  this 
  evening, 
  it 
  

   will 
  be 
  observed 
  that 
  the 
  markings 
  of 
  the 
  plumage 
  are 
  very 
  pronounced, 
  

   while 
  the 
  peculiar 
  form 
  of 
  the 
  bird 
  itself 
  distinguishes 
  it 
  very 
  readily 
  from 
  all 
  

   other 
  New 
  Zealand 
  species. 
  Beyond 
  the 
  general 
  grouping 
  of 
  the 
  colours 
  there 
  

   is 
  nothing 
  to 
  remind 
  us 
  of 
  our 
  own 
  bush-hawk, 
  and 
  that 
  there 
  is 
  no 
  great 
  

   protective 
  resemblance 
  is 
  sufficiently 
  manifest 
  from 
  the 
  fact 
  that 
  our 
  cuckoo 
  

   is 
  persecuted 
  on 
  every 
  possible 
  occasion 
  by 
  the 
  tui, 
  which 
  is 
  timorous 
  enough 
  

   in 
  the 
  presence 
  of 
  a 
  hawk. 
  During 
  a 
  trip, 
  however, 
  on 
  the 
  Continent, 
  in 
  the 
  

   autumn 
  of 
  1871, 
  I 
  found 
  in 
  the 
  Zoological 
  Museum 
  at 
  Frankfort, 
  what 
  

   appeared 
  to 
  be 
  the 
  accipitrine 
  model, 
  in 
  a 
  very 
  striking 
  likeness 
  to 
  our 
  bird. 
  

   Not 
  only 
  has 
  our 
  cuckoo 
  the 
  general 
  contour 
  of 
  Cooper's 
  sparrow-hawk, 
  but 
  

   the 
  tear-shaped 
  markings 
  on 
  the 
  under 
  parts 
  and 
  the 
  arrow-head 
  bars 
  on 
  

   the 
  femoral 
  plumes 
  are 
  exactly 
  similar 
  in 
  both. 
  The 
  resemblance 
  is 
  carried 
  

   still 
  further 
  in 
  the 
  beautifully 
  banded 
  tail 
  and 
  marginal 
  wing-coverts, 
  and 
  

   likewise 
  in 
  the 
  distribution 
  of 
  colours 
  and 
  markings 
  on 
  the 
  sides 
  of 
  the 
  neck. 
  

   On 
  turning 
  to 
  Mr. 
  Sharpe's 
  description 
  of 
  the 
  "young 
  male" 
  of 
  this 
  species 
  

   in 
  his 
  Catalogue 
  of 
  the 
  Accipitres 
  in 
  the 
  British 
  Museum 
  (p. 
  137), 
  it 
  will 
  be 
  

   seen 
  how 
  many 
  of 
  the 
  terms 
  employed 
  apply 
  equally 
  to 
  our 
  Eudynamis, 
  

   even 
  to 
  the 
  general 
  words 
  "deep 
  brown 
  above 
  with 
  a 
  chocolate 
  gloss, 
  all 
  

   the 
  feathers 
  of 
  the 
  upper 
  surface 
  broadly 
  edged 
  with 
  rufous." 
  

  

  The 
  coincident 
  existence 
  of 
  such 
  a 
  remarkable 
  resemblance 
  to 
  a 
  New 
  

   "World 
  form, 
  cannot 
  of 
  course 
  be 
  any 
  protection 
  to 
  an 
  inhabitant 
  of 
  New 
  

   Zealand, 
  and 
  I 
  do 
  not 
  pretend 
  in 
  this 
  instance 
  to 
  apply 
  the 
  rule 
  ; 
  but 
  in 
  the 
  

   light 
  of 
  natural 
  selection, 
  to 
  which 
  at 
  present 
  no 
  limit 
  can 
  be 
  assigned, 
  the 
  

   fact 
  itself 
  is 
  a 
  suggestive 
  one^ 
  the 
  more 
  so 
  when 
  we 
  remember 
  that 
  this 
  

  

  