﻿A 
  Migration 
  of 
  Yellow 
  Butterflies 
  in 
  Trinidad. 
  85 
  

  

  tion 
  of 
  the 
  species 
  and 
  the 
  sex 
  proportions. 
  The 
  butterflies 
  

   were 
  flying 
  so 
  fast 
  that 
  they 
  were 
  not 
  easy 
  to 
  catch, 
  and 
  

   many 
  more 
  escaped 
  than 
  were 
  captured. 
  I 
  then 
  noticed 
  

   that 
  any 
  butterfly 
  narrowly 
  missed 
  was 
  put 
  off 
  its 
  direction 
  

   by 
  the 
  excitement 
  and 
  flew 
  off 
  wildly 
  in 
  any 
  direction. 
  

   Other 
  butterflies 
  close 
  at 
  hand 
  meeting 
  this 
  butterfly 
  flying 
  

   out 
  of 
  the 
  general 
  order 
  would 
  in 
  turn 
  become 
  confused 
  

   and 
  sometimes 
  follow 
  it 
  in 
  its 
  new 
  direction. 
  So 
  that 
  after 
  

   several 
  misses 
  in 
  succession 
  I 
  was 
  surrounded 
  by 
  a 
  number 
  of 
  

   butterflies 
  flying 
  in 
  all 
  directions. 
  If 
  I 
  stopped 
  attempting 
  

   to 
  catch 
  specimens 
  these 
  would 
  gradually 
  pass 
  away, 
  and 
  

   the 
  regular 
  direction 
  of 
  flight 
  would 
  be 
  resumed. 
  

  

  Proportion 
  of 
  Sexes. 
  

   The 
  following 
  actual 
  figures 
  were 
  obtained 
  for 
  catches 
  : 
  — 
  

  

  Port 
  of 
  Spain, 
  end 
  of 
  Sept. 
  5 
  females, 
  1 
  male 
  (T. 
  I. 
  Potter). 
  

   Port 
  of 
  Spain, 
  27th 
  Sept. 
  .9 
  „ 
  10 
  males 
  (C. 
  B. 
  W.). 
  

   Palmisti 
  (S. 
  of 
  San 
  F'do), 
  

  

  30th 
  Sept. 
  . 
  . 
  5 
  ,, 
  4 
  „ 
  (Norman 
  Lamont). 
  

  

  La 
  Brea, 
  4th 
  Oct. 
  . 
  . 
  6 
  ,, 
  i 
  ,, 
  (l^r. 
  Rodriguez). 
  

  

  From 
  these 
  it 
  might 
  be 
  supposed 
  that 
  the 
  sexes 
  were 
  in 
  

   more 
  or 
  less 
  equal 
  proportions, 
  but 
  I 
  am 
  not 
  convinced 
  that 
  

   this 
  was 
  so 
  in 
  the 
  actual 
  flights. 
  All 
  the 
  above 
  records 
  

   suffer 
  from 
  the 
  fact 
  that 
  the 
  females 
  are 
  much 
  more 
  easy 
  to 
  

   catch 
  than 
  the 
  males, 
  and 
  in 
  addition, 
  in 
  certain 
  cases, 
  I 
  

   beheve 
  the 
  specimens 
  were 
  caught 
  not 
  actually 
  on 
  migra- 
  

   tion, 
  but 
  stopping 
  to 
  flutter 
  around 
  flowers 
  on 
  the 
  way. 
  It 
  

   is 
  quite 
  likely 
  that 
  this 
  habit 
  would 
  be 
  found 
  more 
  in 
  the 
  

   females, 
  with 
  eggs 
  to 
  mature, 
  than 
  in 
  the 
  males. 
  

  

  At 
  the 
  time 
  I 
  collected 
  the 
  nineteen 
  specimens 
  mentioned 
  

   above 
  I 
  found 
  that 
  I 
  could, 
  with 
  difficulty, 
  distinguish 
  the 
  

   females 
  from 
  the 
  males 
  in 
  flight, 
  and 
  estimated 
  the 
  propor- 
  

   tion 
  as 
  approximately 
  1 
  female 
  to 
  10 
  males. 
  

  

  Density 
  of 
  Migration 
  and 
  Effects 
  of 
  Sunshine. 
  

  

  It 
  will 
  be 
  seen 
  from 
  the 
  records 
  in 
  the 
  maps 
  that 
  the 
  num- 
  

   bers 
  passing 
  varied 
  from 
  two 
  or 
  three 
  occasional 
  specimens 
  

   to 
  a 
  cloud 
  so 
  dense 
  as 
  to 
  interfere 
  with 
  the 
  progress 
  of 
  a 
  

   motor-car. 
  Perhaps 
  an 
  even 
  better 
  idea 
  of 
  their 
  occasional 
  

   abundance 
  is 
  obtained 
  from 
  one 
  record 
  in 
  which 
  they 
  were 
  

   stated 
  to 
  be 
  passing 
  over 
  a 
  house 
  in 
  the 
  country 
  in 
  such 
  

   immense 
  numbers 
  that 
  the 
  turkeys 
  in 
  the 
  garden 
  looked 
  up 
  

   at 
  them 
  and 
  gobbled 
  in 
  consternation 
  ! 
  

  

  