﻿262 
  PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  able 
  assumption 
  that 
  more 
  cynis 
  would 
  have 
  been 
  taken 
  with 
  an 
  increased 
  

   number 
  of 
  males 
  at 
  Baghownie. 
  The 
  true 
  proportions 
  can 
  only 
  be 
  

   ascertained, 
  as 
  Mr. 
  Fryer 
  has 
  rightly 
  maintained, 
  by 
  breeding 
  from 
  

   indiscriminately 
  collected 
  larvae 
  and 
  it 
  would 
  be 
  deeply 
  interesting 
  to 
  

   check 
  the 
  results 
  shown 
  in 
  the 
  above 
  table 
  in 
  the 
  manner. 
  I 
  sincerely 
  

   hope 
  that 
  this 
  may 
  be 
  possible 
  in 
  both 
  localities. 
  

  

  The 
  great 
  difference 
  between 
  the 
  proportions 
  of 
  the 
  cyrus 
  and 
  polytes 
  

   female 
  forms 
  in 
  the 
  two 
  localities 
  may 
  probably 
  be 
  explained 
  by 
  the 
  

   absence, 
  until 
  recent 
  years, 
  of 
  the 
  aristolochice 
  models 
  at 
  Dehra 
  Dun 
  

   and 
  by 
  similar 
  reasoning 
  we 
  may 
  expect 
  a 
  gradual 
  increase 
  in 
  the 
  

   proportions 
  of 
  the 
  polytes 
  f., 
  now 
  that 
  the 
  model 
  has 
  become 
  common 
  

   there. 
  

  

  The 
  other 
  exceedingly 
  interesting 
  difference, 
  already 
  referred 
  to 
  

   by 
  Mr. 
  C. 
  M. 
  Inglis 
  (p. 
  260), 
  is 
  in 
  the 
  proportions 
  of 
  the 
  romulus 
  f., 
  to 
  be 
  

   doubtless 
  explained, 
  on 
  the 
  lines 
  suggested 
  by 
  him, 
  as 
  the 
  result 
  of 
  the 
  

   much 
  greater 
  distance 
  of 
  Dehra 
  Dun 
  from 
  the 
  range 
  of 
  the 
  model 
  P. 
  

   hector. 
  

  

  I 
  trust 
  that 
  an 
  attempt 
  will 
  be 
  made 
  to 
  breed 
  from 
  one 
  of 
  those 
  

   rare 
  female 
  forms 
  at 
  both 
  localities. 
  The 
  following 
  considerations 
  

   make 
  it 
  almost 
  certain 
  that 
  the 
  great 
  majority 
  of 
  them 
  are 
  heterozy- 
  

   gotes 
  (hybrids) 
  bearing 
  the 
  pattern 
  of 
  the 
  dominant, 
  and 
  the 
  most 
  

   probable 
  mating 
  will 
  have 
  been 
  with 
  a 
  male 
  bearing 
  the 
  polytes 
  or 
  cyrus 
  

   tendencies 
  (both 
  recessive 
  to 
  romulus). 
  The 
  commonest 
  result 
  to 
  be 
  

   expected 
  would 
  therefore 
  be 
  approximately 
  half 
  romulus 
  females 
  (hetero- 
  

   zygotes) 
  and 
  half 
  polytes 
  females 
  (recessives), 
  or 
  half 
  romulus 
  and 
  

   half 
  cyrus. 
  

  

  The 
  reason 
  why 
  the 
  rare 
  romulus 
  forms 
  are 
  likely 
  to 
  be 
  heterozygotes 
  

   is 
  as 
  follows 
  : 
  The 
  handing 
  on 
  of 
  the 
  mimetic 
  pattern 
  from 
  a 
  region 
  

   where 
  it 
  and 
  its 
  model 
  are 
  common, 
  is 
  probably 
  brought 
  about 
  by 
  

   wandering 
  males, 
  although 
  sometimes 
  by 
  regular 
  seasonal 
  or 
  excep- 
  

   tional 
  migrations. 
  When 
  a 
  male 
  bearing 
  the 
  tendency 
  of 
  romidus 
  

   thus 
  reaches 
  a 
  population 
  in 
  which 
  the 
  romulus 
  female 
  is 
  rare 
  or 
  absent 
  

   it 
  will 
  rarely 
  or 
  never' 
  pair 
  with 
  such 
  a 
  fem^ale 
  but 
  with 
  polytes 
  or 
  cyrus, 
  

   or 
  the 
  polytes-like 
  heterozygotes 
  combining 
  the 
  two. 
  In 
  each 
  ease 
  the 
  

   offspring 
  will 
  be 
  heterozygotes, 
  the 
  females 
  bearing 
  the 
  appearance 
  

   of 
  romulus, 
  the 
  survivors 
  of 
  these 
  again 
  will 
  generally 
  pair 
  with 
  males 
  

   bearing 
  the 
  common 
  recessive 
  female 
  patterns, 
  yielding 
  again 
  half 
  

   heterozygotes 
  and 
  half 
  recessives. 
  And 
  even 
  when 
  the 
  rare 
  heterozy- 
  

   gotes 
  romulus 
  female 
  meets 
  and 
  mates 
  with 
  the 
  equally 
  rare 
  male 
  and 
  

   produces 
  offspring 
  of 
  which 
  a 
  quarter 
  are 
  pure 
  dominant 
  romulus, 
  the 
  

   survivors 
  of 
  this 
  will 
  at 
  once 
  tend 
  to 
  mate 
  with 
  the 
  common 
  male, 
  

   yielding 
  again 
  heterzygotes 
  bearing 
  the 
  romulus 
  pattern. 
  Therefore, 
  

  

  