﻿14 
  

  

  BRITISH 
  LEPIDOPTERA. 
  

  

  more 
  ready 
  to 
  respond 
  to 
  environmental 
  influences, 
  although 
  the 
  local 
  

   variation 
  of 
  T. 
  crepuscularia 
  renders 
  the 
  latter 
  scarcely 
  probable. 
  At 
  

   any 
  rate 
  the 
  dominating 
  influence 
  of 
  T. 
  bistortata 
  on 
  the 
  progeny 
  is 
  

   most 
  marked. 
  

  

  As 
  further 
  tending 
  to 
  support 
  his 
  position, 
  Standfuss 
  notes 
  (Entom., 
  

   xxxiv., 
  p. 
  80) 
  that 
  his 
  experiments 
  in 
  hybridising 
  Clostera 
  jrigra, 
  C. 
  

   curtula 
  and 
  C. 
  anachoreta 
  support 
  most 
  strongly 
  the 
  view 
  that 
  the 
  

   characters 
  of 
  the 
  oldest 
  species 
  phylogenetically 
  are 
  most 
  impressed 
  

   upon 
  the 
  offspring, 
  i.e., 
  that 
  the 
  physiognomical 
  aspect 
  of 
  the 
  hybrid 
  

   will 
  be 
  mainly 
  influenced 
  by 
  the 
  phylogenetically 
  oldest 
  species. 
  On 
  

   various 
  grounds, 
  he 
  assumes 
  0. 
  pigra, 
  C. 
  curtula 
  and 
  C. 
  anachoreta 
  to 
  

   stand 
  in 
  this 
  order 
  phylogenetically, 
  and 
  he 
  states 
  (Entom., 
  xxxiv., 
  pp. 
  

   82-3) 
  that, 
  in 
  the 
  crossings 
  of 
  C. 
  pigra 
  3 
  xcurtula 
  $ 
  and 
  C. 
  curtula 
  

   S 
  Xpigra 
  2 
  , 
  the 
  progeny 
  of 
  both 
  are 
  nearer 
  to 
  C. 
  pigra, 
  wmilst, 
  in 
  the 
  

   reciprocal 
  crossings, 
  C. 
  curtula 
  $ 
  x 
  anachoreta 
  2 
  and 
  C. 
  anachoreta 
  $ 
  

   Xcurtula 
  $ 
  , 
  the 
  progeny 
  are 
  nearer 
  the 
  phylogenetically 
  older 
  form 
  

   curtula 
  than 
  the 
  younger 
  anachoreta, 
  but 
  in 
  a 
  subordinate 
  manner 
  the 
  

   influence 
  of 
  the 
  male 
  prevails 
  in 
  the 
  aspect 
  of 
  these 
  reciprocal 
  

   hybrids. 
  Contrary 
  to 
  Standfuss' 
  opinion, 
  Adkin 
  notes 
  (Proc. 
  South 
  

   Lond. 
  Ent. 
  Soc, 
  1902, 
  p. 
  110) 
  that 
  many 
  specimens 
  of 
  both 
  0. 
  hybr. 
  

   prima 
  (curtula 
  $ 
  xpigra 
  ?) 
  and 
  C. 
  hybr. 
  inversa 
  (pigra 
  $ 
  xcurtula 
  

   2 
  ) 
  in 
  his 
  possession 
  more 
  nearly 
  resembled 
  in 
  each 
  case 
  the 
  $ 
  parent 
  

   than 
  the 
  $ 
  , 
  while 
  the 
  markings 
  showed 
  the 
  cross 
  parentage 
  ; 
  and 
  

   Fletcher, 
  who 
  reared 
  imagines 
  of 
  C. 
  pigra 
  $ 
  x 
  curtula 
  $ 
  from 
  pupas 
  

   obtained 
  from 
  Newman, 
  states 
  that 
  the 
  progeny 
  was 
  scarcely 
  different 
  

   from 
  pure 
  bred 
  C. 
  curtula. 
  

  

  As 
  bearing 
  on 
  the 
  question 
  of 
  the 
  influence 
  of 
  the 
  $ 
  parent, 
  we 
  

   may 
  note 
  that 
  in 
  A. 
  hybr. 
  worihingi 
  (lonicerae 
  $ 
  x 
  trifolii 
  2 
  ) 
  there 
  is 
  

   a 
  strong 
  tendency 
  to 
  resemble 
  the 
  mother, 
  although 
  when 
  several 
  

   of 
  a 
  brood 
  are 
  seen 
  together 
  the 
  influence 
  of 
  both 
  parents 
  is 
  very 
  

   marked 
  ; 
  this 
  is 
  especially 
  noticeable 
  in 
  the 
  blotching 
  of 
  the 
  spots 
  of 
  

   the 
  forewings, 
  a 
  very 
  common 
  character 
  in 
  trifolii 
  and 
  a 
  very 
  rare 
  one 
  

   in 
  lonicerae. 
  Fletcher's 
  experiments 
  tend 
  to 
  prove 
  not 
  so 
  much 
  that 
  

   the 
  cf 
  influences 
  most 
  the 
  progeny, 
  as 
  that 
  a 
  particular 
  species 
  (trifolii) 
  

   does 
  it; 
  it 
  may 
  be 
  that 
  this 
  is 
  explicable 
  on 
  the 
  assumption 
  that 
  trifolii 
  

   is, 
  compared 
  "with 
  lonicerae, 
  the 
  older 
  species 
  phylogenetically, 
  an 
  

   assumption 
  that 
  we 
  are 
  not 
  altogether 
  inclined 
  to 
  support, 
  trifolii 
  

   being 
  even 
  now 
  in 
  a 
  state 
  of 
  flux 
  with 
  regard 
  to 
  its 
  species-forming 
  

   power, 
  and 
  lonicerae 
  one 
  of 
  the 
  most 
  fixed 
  and 
  constant 
  in 
  the 
  

   Anthrocerid 
  fauna, 
  and 
  maintaining 
  its 
  fixity 
  under 
  a 
  variety 
  of 
  

   conditions 
  of 
  environment, 
  latitude 
  and 
  altitude. 
  

  

  It 
  is 
  now 
  generally 
  accepted 
  that 
  increase 
  in 
  the 
  number 
  of 
  species 
  

   is 
  due 
  either 
  (1) 
  To 
  the 
  modification 
  of 
  an 
  existent 
  species 
  by 
  changed 
  

   environment; 
  or 
  (2) 
  To 
  the 
  splitting 
  up 
  of 
  a 
  species 
  into 
  more 
  than 
  one 
  

   by 
  various 
  changed 
  conditions 
  acting 
  on 
  the 
  original 
  species. 
  The 
  

   early 
  separation 
  of 
  these 
  forms 
  gives 
  us 
  what 
  are 
  known 
  as 
  local 
  races, 
  

   the 
  impress 
  of 
  the 
  different 
  conditions 
  to 
  which 
  they 
  are 
  subjected 
  

   developing 
  a 
  divergence 
  of 
  habit, 
  form, 
  colour, 
  or 
  other 
  outward 
  

   conditions 
  accompanied 
  by 
  modified 
  anatomical 
  or 
  physiological 
  

   (functional) 
  changes. 
  When 
  these 
  diverging 
  forms 
  have 
  become 
  quite 
  

   isolated 
  we 
  call 
  them 
  species, 
  and, 
  by 
  the 
  time 
  this 
  stage 
  has 
  been 
  

   reached, 
  the 
  forms 
  are 
  usually 
  so 
  divergent 
  that 
  they 
  do 
  not 
  cross 
  and 
  

   produce 
  offspring 
  that 
  are 
  fertile 
  inter 
  se, 
  not, 
  perhaps, 
  so 
  much 
  from 
  

  

  