﻿84 
  Mr. 
  C. 
  B. 
  Williams 
  on 
  

  

  Direction 
  and 
  Keversal 
  of 
  Flight. 
  

  

  E. 
  Goeldi, 
  in 
  his 
  account 
  of 
  the 
  butterfly 
  migration 
  in 
  

   Brazil 
  (Bol., 
  p. 
  313) 
  comments 
  on 
  the 
  contradictory 
  reports 
  

   of 
  the 
  direction 
  of 
  flight 
  in 
  various 
  previous 
  accounts 
  of 
  

   migration, 
  and 
  states 
  that 
  he 
  has 
  discovered 
  the 
  solution, 
  

   which 
  is 
  that 
  there 
  is 
  a 
  reversal 
  of 
  direction 
  during 
  the 
  day. 
  

   In 
  the 
  case 
  he 
  describes 
  the 
  butterflies 
  were 
  flying 
  along 
  a 
  

   branch 
  of 
  the 
  River 
  Amazon 
  from 
  north 
  to 
  south 
  during 
  the 
  

   morning 
  and 
  from 
  south 
  to 
  north 
  during 
  the 
  afternoon, 
  the 
  

   reversal 
  being 
  quite 
  regular 
  each 
  day. 
  There 
  is 
  no 
  reason 
  

   to 
  doubt 
  for 
  a 
  moment 
  his 
  observations, 
  and 
  I 
  have 
  noticed 
  

   a 
  somewhat 
  similar 
  occurrence 
  in 
  the 
  migration 
  of 
  a 
  

   Hesperid 
  butterfly 
  in 
  Panama, 
  which 
  I 
  hope 
  to 
  describe 
  

   later, 
  but 
  in 
  the 
  migration 
  of 
  Catopsilia 
  statira 
  at 
  present 
  

   under 
  consideration 
  there 
  is 
  no 
  evidence 
  to 
  prove 
  that 
  this 
  

   was 
  happening. 
  

  

  It 
  must 
  be 
  admitted 
  that 
  throughout 
  the 
  migration 
  there 
  

   were 
  heavy 
  rains 
  nearly 
  every 
  afternoon, 
  and 
  usually 
  the 
  

   migration 
  for 
  the 
  day 
  ceased 
  when 
  these 
  began, 
  but 
  on 
  the 
  

   few 
  fine 
  afternoons, 
  and 
  occasionally 
  after 
  the 
  rains, 
  the 
  

   direction 
  of 
  flight 
  when 
  recorded 
  was 
  nearly 
  always 
  similar 
  

   to 
  the 
  regular 
  direction 
  of 
  the 
  morning. 
  

  

  The 
  flight 
  for 
  the 
  day 
  usually 
  started 
  at 
  9.30 
  a.m. 
  or 
  even 
  a 
  

   little 
  later, 
  but 
  I 
  have 
  several 
  records 
  as 
  early 
  as 
  8 
  a.m. 
  and 
  

   in 
  two 
  cases 
  at 
  7 
  a.m. 
  There 
  is 
  shght 
  evidence 
  of 
  change 
  of 
  

   direction 
  one 
  day 
  at 
  San 
  Fernando 
  (1.x.), 
  when 
  the 
  flight 
  

   was 
  towards 
  the 
  north-west 
  in 
  the 
  morning 
  and 
  towards 
  

   the 
  south-west 
  in 
  the 
  afternoon 
  after 
  the 
  rains, 
  but 
  this 
  

   could 
  scarcely 
  be 
  classed 
  as 
  a 
  reversal 
  of 
  direction. 
  On 
  the 
  

   other 
  hand, 
  the 
  flights 
  from 
  west 
  to 
  east 
  that 
  are 
  recorded 
  

   from 
  Port 
  of 
  Spain 
  district 
  on 
  the 
  28th, 
  29th, 
  30th 
  Septem- 
  

   ber, 
  and 
  2nd 
  and 
  3rd 
  October, 
  do 
  not 
  appear 
  to 
  have 
  been 
  

   in 
  any 
  way 
  connected 
  with 
  the 
  time 
  of 
  day. 
  

  

  In 
  cases 
  where 
  the 
  migration 
  is 
  very 
  thin 
  and 
  the 
  butter- 
  

   flies 
  are 
  only 
  passing 
  at 
  intervals, 
  the 
  direction 
  of 
  flight 
  of 
  

   one 
  butterfly 
  is 
  not 
  hkely 
  to 
  influence 
  directly 
  that 
  of 
  an- 
  

   other. 
  But 
  when 
  the 
  flight 
  is 
  more 
  dense 
  this 
  may 
  happen, 
  

   and 
  the 
  foUowing 
  observation 
  may 
  be 
  of 
  interest 
  in 
  this 
  

   connection. 
  

  

  On 
  the 
  27th 
  September 
  the 
  butterflies 
  were 
  passing 
  at 
  

   the 
  rate 
  of 
  50 
  to 
  100 
  per 
  minute 
  across 
  a 
  hundred 
  yards 
  hne 
  

   over 
  the 
  Savannah 
  in 
  Port 
  of 
  Spain 
  about 
  1 
  p.m. 
  I 
  went 
  

   out 
  with 
  a 
  net 
  in 
  order 
  to 
  catch 
  specimens 
  for 
  the 
  determina- 
  

  

  