﻿ADDENDUM 
  I 
  HYBRIDISATION 
  IN 
  LEPIDOPTERA. 
  539 
  

  

  nearer 
  that 
  of 
  vespertilio 
  at 
  the 
  same 
  stage. 
  The 
  shield 
  on 
  the 
  head 
  is 
  

   black, 
  and 
  the 
  prolegs 
  vary 
  from 
  green, 
  as 
  in 
  vespertilio, 
  to 
  black, 
  as 
  

   in 
  eaphorbiae. 
  The 
  stigmatal 
  line 
  is 
  more 
  distinctly 
  marked 
  than 
  in 
  

   euphorbiae, 
  less 
  so 
  than 
  in 
  vespertilio. 
  The 
  caudal 
  horn 
  is 
  short 
  and 
  

   stumpy, 
  relatively 
  the 
  same 
  length 
  as 
  in 
  the 
  first 
  stage 
  ; 
  exceptionally, 
  

   in 
  a 
  very 
  few 
  cases, 
  it 
  is 
  completely 
  missing 
  (in 
  not 
  one 
  case 
  was 
  it 
  

   wanting 
  in 
  the 
  first 
  stage). 
  Third 
  (and 
  final) 
  stage: 
  The 
  larva 
  of 
  

   densoi 
  varies 
  in 
  the 
  adult 
  stage 
  very 
  much 
  more 
  than 
  in 
  the 
  first 
  two 
  

   stages, 
  but 
  is, 
  altogether, 
  within 
  the 
  broad 
  limits 
  of 
  the 
  euphorbiae 
  

   larvae, 
  from 
  which, 
  however, 
  it 
  differs 
  with 
  regard 
  to 
  the 
  length 
  of 
  

   the 
  caudal 
  horn. 
  In 
  no 
  case 
  was 
  this 
  horn 
  more 
  than 
  one-half 
  the 
  

   size 
  of 
  the 
  caudal 
  horn 
  of 
  euphorbiae, 
  and, 
  in 
  several 
  cases, 
  it 
  did 
  not 
  

   exist 
  at 
  all. 
  In 
  the 
  course 
  of 
  the 
  last 
  stage 
  the 
  larvae 
  were 
  attacked 
  

   by 
  the 
  fatal 
  "flacherie," 
  and, 
  in 
  spite 
  of 
  every 
  care, 
  90 
  per 
  cent, 
  

   perished. 
  Pup.se. 
  — 
  These 
  are 
  rather 
  nearer 
  vespertilio 
  than 
  euphorbiae 
  

   in 
  size 
  and 
  general 
  appearance 
  ; 
  the 
  black 
  markings 
  (almost 
  non- 
  

   existent 
  in 
  vespertilio) 
  are 
  clearly 
  defined, 
  though 
  not 
  so 
  dark 
  as 
  in 
  

   euphorbiae. 
  To 
  obtain 
  these 
  hybrids 
  several 
  Thaumas 
  vespertilio 
  3 
  s 
  and 
  

   Hyles 
  euphorbiae 
  $ 
  s 
  were 
  placed, 
  in 
  June, 
  1906, 
  by 
  Dr. 
  Denso, 
  in 
  one 
  

   side 
  of 
  a 
  silk-covered 
  cage, 
  and, 
  on 
  the 
  other 
  side, 
  separated 
  only 
  by 
  a 
  fine 
  

   silken 
  screen, 
  a 
  few 
  H. 
  euphorbiae 
  $ 
  sand 
  T. 
  vespertilio 
  $ 
  s. 
  Of 
  the 
  former, 
  

   two 
  euphorbiae 
  2 
  s 
  paired 
  at 
  once 
  with 
  vespertilio 
  $ 
  s, 
  and 
  subsequently 
  

   laid 
  respectively 
  108 
  and 
  97 
  eggs. 
  No 
  pairing, 
  however, 
  took 
  place 
  

   between 
  vespertilio 
  ? 
  s 
  and 
  euphorbiae 
  $ 
  s. 
  The 
  eggs 
  all 
  hatched, 
  and 
  

   the 
  larvae 
  at 
  first 
  did 
  well, 
  feeding 
  hungrily 
  on 
  Euphorbia, 
  and 
  

   continued 
  to 
  do 
  so 
  up 
  to 
  the 
  final 
  stage 
  (Muschamp). 
  

  

  Attacides. 
  [To 
  p. 
  27.] 
  Saturnia 
  hybr. 
  casparii* 
  (hybrida 
  $ 
  

   X 
  pavonia 
  2 
  ), 
  Frings, 
  Soc. 
  Ent., 
  xxi., 
  p. 
  25 
  (1906). 
  — 
  Imago. 
  — 
  

   Very 
  close 
  to 
  S. 
  pavonia 
  ; 
  the 
  $ 
  antennae 
  rather 
  more 
  expanded 
  

   and 
  body 
  rather 
  more 
  robust. 
  The 
  basal 
  transverse 
  line 
  of 
  fore- 
  

   wings 
  not 
  nearly 
  so 
  strongly 
  angulated, 
  sometimes 
  nearly 
  straight, 
  

   as 
  in 
  spini 
  ; 
  the 
  second 
  sinuate 
  line 
  runs 
  nearer 
  to 
  the 
  base 
  as 
  in 
  

   hybrida-minor. 
  Forewings 
  of 
  $ 
  rather 
  of 
  a 
  grey-brown, 
  not 
  so 
  bright 
  

   a 
  brown 
  as 
  in 
  pavonia, 
  though 
  they 
  retain 
  the 
  admixture 
  of 
  red 
  in 
  the 
  

   disc. 
  The 
  coloration 
  of 
  the 
  hindwings 
  is 
  very 
  interesting 
  ; 
  in 
  one 
  

   example 
  the 
  hindwings 
  are 
  of 
  the 
  pale 
  grey 
  of 
  spini, 
  but, 
  in 
  some 
  others, 
  

   they 
  attain 
  the 
  intensity 
  of 
  a 
  rather 
  pale 
  pavonia, 
  these 
  two 
  forms 
  being 
  

   connected 
  by 
  intermediates. 
  Sometimes 
  the 
  base 
  and 
  disc 
  are 
  orange, 
  

   but 
  the 
  hindmargin 
  dusky-grey 
  as 
  in 
  hybrida-minor. 
  The 
  underside 
  

   varies 
  from 
  almost 
  as 
  deep 
  an 
  orange 
  as 
  pavonia 
  to 
  quite 
  a 
  grey 
  colour. 
  

   The 
  $ 
  hybr. 
  casparii, 
  therefore, 
  connects 
  hybrida-minor 
  and 
  pavonia 
  

  

  * 
  The 
  parentage 
  of 
  this 
  hybrid 
  is 
  given 
  as 
  hybrida-minor 
  <? 
  x 
  pavonia 
  ? 
  . 
  

   As 
  we 
  have 
  already 
  noted 
  (anted, 
  vol. 
  iii. 
  , 
  p. 
  297) 
  S. 
  hybr. 
  hybrida 
  (or 
  as 
  it 
  was 
  later 
  

   called 
  hybrida-minor) 
  has 
  never 
  yet 
  been 
  recorded 
  as 
  reared 
  in 
  confinement, 
  audits 
  

   existence 
  is 
  assumed 
  only 
  on 
  the 
  strength 
  of 
  captured 
  specimens. 
  Frings, 
  unfor- 
  

   tunately, 
  does 
  not 
  say 
  whether 
  Caspari 
  obtained 
  his 
  £ 
  parent, 
  for 
  this 
  crossing, 
  in 
  

   confinement, 
  or 
  whether 
  it 
  was 
  captured 
  wild. 
  It 
  really 
  is 
  a 
  most 
  important 
  

   detail, 
  as 
  some 
  pavonia 
  exhibit 
  usually-considered 
  spini 
  characters. 
  Frings 
  

   himself 
  notes 
  that 
  two 
  of 
  the 
  generally 
  accepted 
  differences 
  between 
  spini 
  

   and 
  pavonia 
  are 
  not 
  to 
  be 
  relied 
  on, 
  viz., 
  (1) 
  Basal 
  line- 
  a 
  ? 
  pavonia 
  bred 
  from 
  a 
  

   pupa 
  taken 
  at 
  Bonn, 
  with 
  basal 
  line 
  exactly 
  as 
  in 
  spini 
  ?; 
  ho 
  has 
  also 
  captured 
  

   a 
  similarly 
  marked 
  d 
  , 
  and 
  has 
  seen 
  others 
  from 
  Budapest. 
  Russian 
  Poland, 
  and 
  

   Ferrara. 
  (2) 
  Abdominal 
  band* 
  — 
  ?s 
  from 
  Rhenish 
  Prussia 
  often 
  have 
  the 
  pale 
  

   abdominal 
  bands 
  as 
  broadly 
  and 
  strongly 
  white-ringed 
  as 
  those 
  of 
  tpini. 
  On 
  the 
  

   other 
  hand, 
  examples 
  from 
  Dalmatia 
  possess 
  no 
  white 
  rings. 
  

  

  