﻿16 
  

  

  BRITISH 
  LEPIDOPTERA. 
  

  

  was 
  corydon 
  and 
  the 
  female 
  bellargus 
  (see 
  Ent. 
  Rec, 
  iv., 
  p. 
  230 
  ; 
  Trans. 
  

   Knt. 
  Soc. 
  Lond., 
  1894, 
  p. 
  xv). 
  On 
  the 
  other 
  hand, 
  we 
  have 
  already 
  given 
  

   instances 
  in 
  which 
  divergence 
  from 
  both 
  parent 
  forms 
  occur, 
  and 
  where 
  

   isolation 
  is 
  fairly 
  certain 
  to 
  lead 
  to 
  their 
  failure 
  to 
  maintain 
  themselves. 
  

   The 
  evidence 
  relating 
  to 
  hybridity 
  in 
  lepidoptera 
  is 
  of 
  two 
  distinct 
  

   kinds 
  : 
  (1) 
  That 
  in 
  which 
  the 
  parentage 
  is 
  known, 
  the 
  crossings 
  

   having 
  been 
  brought 
  about 
  as 
  the 
  result 
  of 
  artificial 
  conditions 
  

   determined 
  by 
  the 
  operator. 
  (2) 
  The 
  capture 
  in 
  nature 
  of 
  individuals 
  

   bearing 
  apparent 
  resemblance 
  to 
  two 
  species, 
  the 
  parentage 
  being 
  

   altogether 
  unknown. 
  Evidence 
  of 
  the 
  latter 
  kind 
  must 
  be 
  accepted 
  

   with 
  very 
  great 
  caution. 
  It 
  is 
  well-known 
  to 
  all 
  experienced 
  field- 
  

   naturalists 
  that, 
  within 
  the 
  limits 
  of 
  a 
  small 
  group 
  of 
  closely-allied 
  

   species, 
  variation 
  runs 
  frequently 
  in 
  the 
  same 
  direction, 
  so 
  that 
  

   parallel 
  forms 
  are 
  found, 
  that 
  bear 
  more 
  or 
  less 
  close 
  resemblance 
  

   to 
  one 
  another, 
  and 
  so 
  that 
  a 
  rare 
  aberration 
  of 
  one 
  species 
  may 
  

   bear 
  considerable 
  superficial 
  resemblance 
  to 
  the 
  typical 
  form 
  of 
  another 
  

   species. 
  Such 
  specimens, 
  even 
  to 
  those 
  who 
  have 
  considerable 
  

   knowledge 
  of 
  the 
  group, 
  have 
  often 
  proved 
  a 
  stumbling-block, 
  whilst 
  

   to 
  those 
  whose 
  experience 
  is 
  small 
  they 
  form 
  a 
  pitfall, 
  the 
  readiest 
  

   escape 
  from 
  which 
  is 
  to 
  explain 
  the 
  puzzling 
  form 
  as 
  a 
  hybrid 
  between 
  

   the 
  two 
  species, 
  i.e., 
  the 
  species 
  which 
  it 
  superficially 
  resembles 
  and 
  

   the 
  species 
  to 
  which 
  it 
  really 
  belongs. 
  We 
  do 
  not 
  wish 
  to 
  be 
  under- 
  

   stood 
  as 
  suggesting 
  that 
  there 
  are 
  no 
  natural 
  hybrids, 
  which 
  is, 
  

   indeed, 
  contrary 
  to 
  our 
  opinion, 
  but 
  we 
  should 
  be 
  unwilling 
  to 
  

   acknowledge 
  as 
  hybrids 
  any 
  specimens 
  that 
  did 
  not 
  exhibit 
  struc- 
  

   turally 
  some 
  difference 
  that 
  would 
  bring 
  the 
  supposition 
  largely 
  within 
  

   the 
  bounds 
  of 
  possibility. 
  Mere 
  coloration 
  we 
  should, 
  as 
  a 
  rule, 
  hold 
  to 
  

   be 
  altogether 
  insufficient 
  evidence. 
  A 
  similar 
  feeling 
  that 
  many 
  of 
  the 
  

   so-called 
  hybrids 
  that 
  have 
  been 
  recorded 
  may 
  be 
  merely 
  unusual 
  aber- 
  

   rations 
  of 
  well 
  known 
  species, 
  must 
  have 
  led 
  to 
  Stanclfuss 
  making 
  the 
  

   remark 
  (Handbk. 
  Pal. 
  Gross-Sclimett., 
  pp. 
  51-52) 
  that 
  much 
  of 
  the 
  

   so-called 
  hybrid 
  material 
  is 
  untrustworthy, 
  and 
  that 
  many 
  of 
  the 
  

   so-called 
  hybrids 
  are 
  merely 
  aberrations. 
  Yet 
  some 
  of 
  his 
  own 
  remarks 
  

   on 
  the 
  matter 
  are 
  particularly 
  unsatisfactory, 
  e.g., 
  he 
  records 
  that 
  

   he 
  reared 
  many 
  specimens 
  from 
  larvae 
  found 
  on 
  Bhamnus 
  cathartieus 
  

   and 
  R. 
  alaternus 
  in 
  Dalmatia 
  and 
  Italy, 
  and 
  supposed 
  to 
  be 
  those 
  of 
  

   Gonepteryx 
  cleopatra, 
  that 
  he 
  considered 
  could 
  be 
  nothing 
  but 
  hybrids 
  

   between 
  G. 
  rhamni 
  and 
  G. 
  cleopatra. 
  Again 
  he 
  observes 
  that 
  Melitaea 
  

   dictynna, 
  M. 
  athalia, 
  31. 
  aurelia 
  and 
  31. 
  parthenie 
  are 
  so 
  nearly 
  related 
  

   to 
  one 
  another 
  that 
  a 
  particular 
  hybrid 
  appearance 
  can 
  scarcely 
  occur, 
  

   the 
  markings 
  of 
  these 
  species, 
  except 
  in 
  striking 
  occasional 
  aberrations, 
  

   being 
  so 
  very 
  similar. 
  He, 
  however, 
  believes 
  that, 
  among 
  other 
  

   Melitaeids 
  sent 
  to 
  him 
  for 
  determination, 
  many 
  examples, 
  chiefly 
  from 
  

   Switzerland, 
  have 
  had 
  a 
  distinct 
  hybrid 
  origin. 
  He 
  further 
  assumes 
  that 
  

   some 
  of 
  the 
  Erebiids 
  that 
  he 
  has 
  examined, 
  in 
  the 
  epiphron, 
  melampus, 
  

   eriphyle, 
  and 
  mnestra 
  group, 
  have 
  been 
  the 
  result 
  of 
  crosspairing 
  

   between 
  different 
  species. 
  We 
  have 
  examined 
  some 
  thousands 
  of 
  the 
  

   Melitaeid 
  and 
  Erebiid 
  species 
  mentioned 
  by 
  Standfuss, 
  and 
  have 
  never 
  

   seen 
  a 
  specimen 
  that 
  we 
  could 
  in 
  anyway 
  suppose 
  was 
  a 
  hybrid. 
  

   Such 
  evidence 
  as 
  Standfuss 
  thus 
  offers 
  is 
  very 
  unconvincing, 
  and 
  

   appears 
  to 
  have 
  little 
  real 
  bearing 
  on 
  the 
  solution 
  of 
  the 
  problems 
  

   relating 
  to 
  hybridity 
  in 
  butterflies. 
  The 
  pairings 
  between 
  butterflies 
  

   of 
  different 
  species 
  (antea, 
  p. 
  3) 
  also 
  carry 
  our 
  knowledge 
  of 
  whether 
  

  

  