﻿HYBRIDISATION 
  IN 
  LEPIDOPTERA. 
  U 
  

  

  (antea, 
  vol. 
  iii., 
  p. 
  302) 
  of 
  the 
  gynandromorphic 
  hybrids 
  among 
  the 
  

   Saturniids, 
  and 
  it 
  is 
  to 
  be 
  noted 
  that, 
  although 
  g 
  hybrids 
  among 
  the 
  

   Saturniids 
  have 
  frequently 
  fertilised 
  $ 
  s 
  of 
  either 
  parent 
  form, 
  very 
  

   few 
  2 
  hybrids 
  have 
  ever 
  been 
  fertilised 
  either 
  by 
  $ 
  s 
  of 
  their 
  own 
  

   kind 
  or 
  of 
  their 
  respective 
  parent 
  forms. 
  Anatomical 
  investigation 
  

   into 
  the 
  structure 
  of 
  $ 
  and 
  $ 
  hybrids 
  is 
  still 
  much 
  needed. 
  

  

  So 
  much 
  for 
  the 
  questions 
  of 
  infertility 
  and 
  sterility 
  in 
  first 
  crosses, 
  

   and 
  the 
  hybrids 
  arising 
  therefrom. 
  The 
  difficulties 
  of 
  hybrids 
  reaching 
  

   maturity 
  do 
  not, 
  however, 
  end 
  with 
  the 
  successful 
  hatching 
  of 
  the 
  

   hybrid 
  larva. 
  The 
  larva, 
  compounded 
  as 
  it 
  is 
  of 
  the 
  differing 
  anatomical, 
  

   physiological, 
  morphological, 
  and 
  molecular 
  conditions 
  and 
  peculiarities 
  

   belonging 
  to 
  two 
  distinct 
  species, 
  having 
  in 
  each 
  case 
  highly 
  specialised 
  

   larvae 
  of 
  their 
  own, 
  with 
  differing 
  constitutions, 
  habits, 
  and 
  maybe 
  

   foodplants, 
  may 
  find 
  itself 
  unable 
  to 
  deal 
  satisfactorily 
  with 
  the 
  

   foodplant 
  of 
  either 
  parent, 
  may 
  find 
  its 
  alimentary 
  system 
  so 
  far 
  dis- 
  

   turbed 
  as 
  to 
  be 
  unable 
  to 
  satisfactorily 
  digest 
  these 
  foodplants, 
  may 
  find 
  

   its 
  habits 
  so 
  complex 
  that, 
  whilst 
  the 
  half 
  inherited 
  from 
  one 
  parent 
  

   tends 
  to 
  make 
  it 
  hybernate 
  as 
  larva, 
  that 
  inherited 
  from 
  the 
  other 
  

   parent 
  tends 
  to 
  make 
  it 
  hybernate 
  as 
  pupa; 
  may 
  find 
  its 
  mixed 
  habits, 
  

   exposing 
  it 
  to 
  the 
  attacks 
  of 
  foes 
  from 
  which 
  the 
  habit 
  of 
  either 
  

   parent 
  alone 
  would 
  protect 
  it. 
  Hence 
  there 
  may 
  be 
  many 
  difficulties 
  

   in 
  bringing 
  the 
  larva 
  to 
  maturity, 
  and, 
  when 
  this 
  has 
  been 
  done, 
  it 
  is 
  

   often 
  found 
  that 
  the 
  time 
  of 
  emergence 
  of 
  the 
  imago 
  has 
  been 
  greatly 
  

   hastened 
  or 
  retarded, 
  agreeing 
  with 
  that 
  of 
  neither 
  parent, 
  and 
  hence 
  

   tending 
  to 
  its 
  isolation 
  and 
  rapid 
  extermination. 
  On 
  the 
  other 
  hand, 
  

   when 
  the 
  hybrid 
  follows 
  the 
  habits 
  of 
  one 
  of 
  the 
  parents, 
  and 
  emerges 
  

   with 
  the 
  progeny 
  of 
  one 
  of 
  them, 
  there 
  is 
  no 
  doubt 
  that, 
  if 
  functionally 
  

   active, 
  it 
  would 
  cross 
  therewith, 
  and 
  that 
  its 
  progeny 
  would 
  show 
  

   little 
  trace 
  of 
  the 
  hybrid 
  origin 
  of 
  the 
  other 
  of 
  its 
  parents. 
  This 
  leads 
  

   us 
  to 
  note 
  Darwin's 
  statement 
  that 
  " 
  in 
  hybrids, 
  the 
  external 
  conditions 
  

   have 
  remained 
  the 
  same, 
  but 
  the 
  organisation 
  has 
  been 
  disturbed 
  by 
  

   two 
  distinct 
  structures 
  and 
  constitutions, 
  including, 
  of 
  course, 
  the. 
  

   reproductive 
  systems, 
  having 
  been 
  blended 
  into 
  one." 
  To 
  the 
  first 
  

   part 
  of 
  this 
  statement, 
  our 
  remarks 
  above 
  will 
  show 
  that 
  we 
  take 
  

   great 
  objection. 
  External 
  conditions 
  have 
  not 
  remained 
  the 
  same 
  ; 
  

   the 
  whole 
  environment 
  is 
  altered 
  ; 
  the 
  new 
  organism 
  has 
  to 
  choose 
  

   between 
  two 
  foodplants 
  or 
  two 
  sets 
  of 
  foodplants, 
  and, 
  in 
  natural 
  

   hybrids, 
  this 
  choice 
  is 
  practically 
  non-existent, 
  for 
  the 
  $ 
  parent 
  will 
  

   naturally 
  lay 
  her 
  eggs 
  on 
  her 
  own 
  foodplant, 
  and 
  any 
  hereditary 
  tendency 
  

   in 
  the 
  larva 
  to 
  insist 
  on 
  the 
  foodplant 
  of 
  the 
  $ 
  parent 
  spells 
  death. 
  It 
  

   has 
  also 
  to 
  choose 
  between 
  two 
  entirely 
  different 
  sets 
  of 
  habits, 
  and 
  may 
  

   choose 
  some 
  intermediate 
  condition 
  that 
  is 
  unavailable, 
  &c. 
  As 
  to 
  

   the 
  combination 
  of 
  two 
  organisations, 
  we 
  are 
  quite 
  of 
  Darwin's 
  

   opinion, 
  that 
  " 
  it 
  is 
  scarcely 
  possible 
  that 
  two 
  organisations 
  should 
  be 
  

   compounded 
  into 
  one, 
  without 
  some 
  disturbance 
  occurring, 
  in 
  the 
  

   development, 
  or 
  periodical 
  action, 
  or 
  mutual 
  relations, 
  of 
  the 
  different 
  

   parts 
  and 
  organs 
  one 
  to 
  another 
  or 
  to 
  the 
  conditions 
  of 
  life. 
  When 
  

   hybrids 
  are 
  able 
  to 
  breed 
  inter 
  n<\ 
  they 
  transmit 
  to 
  their 
  offspring 
  from 
  

   generation 
  to 
  generation 
  the 
  same 
  compounded 
  organisation, 
  and 
  hence 
  

   we 
  need 
  not 
  be 
  surprised 
  that- 
  their 
  sterility, 
  though 
  in 
  some 
  degree 
  

   variable, 
  docs 
  not 
  diminish 
  ; 
  it 
  is 
  even 
  apt 
  to 
  increase, 
  this 
  being 
  

   generally 
  the 
  result, 
  as 
  before 
  explained, 
  of 
  boo 
  close 
  interbreeding. 
  

   It 
  must, 
  however, 
  be 
  owned 
  that 
  we 
  cannot 
  understand, 
  on 
  the 
  above 
  

  

  