﻿RETURNING 
  SWARMS 
  IN 
  AFRICA. 
  IT 
  

  

  in 
  the 
  middle 
  of 
  the 
  summer 
  ; 
  aud 
  return 
  in 
  the 
  winter, 
  when 
  they 
  are 
  or 
  

   a 
  maroon 
  color, 
  with 
  the 
  extremities 
  yellow. 
  It 
  is 
  evident 
  that 
  the 
  win- 
  

   ter 
  brood 
  is 
  not 
  the 
  same 
  as 
  the 
  summer 
  brood 
  going 
  south, 
  nor 
  do 
  we 
  

   presume 
  the 
  language 
  used 
  was 
  intended 
  to 
  convey 
  this 
  idea. 
  It 
  appears 
  

   from 
  the 
  statement 
  of 
  M. 
  Girard 
  that 
  those 
  hatched 
  in 
  Algiers, 
  in 
  1866, 
  

   migrated 
  westward 
  and 
  southwest 
  in 
  January, 
  but 
  this 
  is 
  spoken 
  of 
  as 
  

   unusual. 
  

  

  There 
  is 
  some 
  evidence, 
  though 
  not 
  decisive, 
  that 
  in 
  Central 
  Africa 
  

   the 
  resulting 
  swarms 
  return 
  northward, 
  as, 
  for 
  example, 
  the 
  swarm 
  seen 
  

   by 
  Barth 
  in 
  July, 
  1854 
  

  

  If. 
  Brue 
  irs 
  mentions 
  the 
  fact 
  of 
  swarms 
  which 
  had 
  moved 
  southward 
  

   in 
  Senegal 
  returning 
  northward 
  to 
  the 
  desert. 
  The 
  same 
  disposition 
  to 
  

   return 
  to 
  the 
  land 
  of 
  their 
  nativity 
  is 
  exhibited 
  by 
  the 
  offspring 
  of 
  those 
  

   visiting 
  Southern 
  Africa. 
  

  

  The 
  locusts 
  which 
  plagued 
  Pharaoh 
  came 
  from 
  the 
  east 
  (Arabia) 
  on 
  an 
  

   ^ast 
  wind, 
  and 
  in 
  attempting 
  to 
  return 
  on 
  a 
  west 
  wind 
  were 
  engulphed 
  

   in 
  the 
  sea 
  1 
  -" 
  6 
  . 
  Bichard 
  Jobson, 
  1 
  " 
  notes 
  a 
  similar 
  case. 
  Niebuhr 
  1?8 
  says 
  

   that 
  swarms 
  frequently 
  cross 
  the 
  Bed 
  Sea 
  a 
  second 
  time 
  and 
  return 
  to 
  

   Egypt, 
  the 
  upp 
  er 
  part 
  of 
  which, 
  adjoining 
  the 
  deserts 
  of 
  Lybia 
  seems 
  to 
  

   be 
  the 
  cradle 
  of 
  these 
  animals. 
  Whether 
  correct 
  or 
  not 
  in 
  reference 
  to 
  

   their 
  •• 
  cradle." 
  these 
  reverse 
  movements 
  indicate 
  clearly 
  a 
  disposition 
  to 
  

   return 
  to 
  the 
  place 
  of 
  their 
  nativity. 
  

  

  From 
  these 
  facts, 
  and 
  others 
  which 
  might 
  be 
  mentioned, 
  we 
  feel 
  justi- 
  

   fied 
  in 
  assuming 
  that 
  it 
  is 
  a 
  characteristic 
  of 
  this 
  species, 
  as 
  of 
  C. 
  spretus, 
  

   for 
  the 
  resulting 
  broods 
  to 
  return 
  to 
  their 
  normal 
  habitat, 
  especially 
  

   where 
  the 
  direction 
  of 
  the 
  invading 
  movements 
  is 
  northward 
  or 
  south- 
  

   ward. 
  

  

  Shaw 
  mentions 
  expressly 
  that 
  the 
  locusts 
  return 
  to 
  the 
  desert 
  to 
  de- 
  

   posit 
  their 
  eggs. 
  Speaking 
  of 
  his 
  observations 
  in 
  Barbary, 
  he 
  says 
  that 
  

   towards 
  the 
  middle 
  of 
  April 
  (1724) 
  the 
  locusts 
  had 
  so 
  multiplied 
  that> 
  

   they 
  formed 
  clouds 
  which 
  darkened 
  the 
  sun. 
  About 
  the 
  middle 
  of 
  May 
  

   their 
  ovaries 
  were 
  filled 
  and 
  they 
  began 
  to 
  move 
  backwards 
  into 
  the 
  

   plains 
  of 
  Metidja 
  and 
  other 
  adjoining 
  regions 
  in 
  order 
  to 
  deposit 
  their 
  

   <>ggs. 
  

  

  The 
  same 
  disposition 
  to 
  return 
  to 
  their 
  native 
  breeding 
  grounds 
  is 
  

   -shown 
  by 
  the 
  A. 
  paranense 
  in 
  its 
  movements 
  in 
  Paraguay, 
  as 
  indicated 
  

   by 
  Bengger. 
  179 
  

  

  c. 
  Local 
  flights. 
  — 
  In 
  our 
  former 
  report 
  this 
  term 
  was 
  applied 
  only 
  to 
  

   the 
  movements 
  of 
  those 
  locusts 
  hatched 
  in 
  the 
  temporary 
  regions 
  to 
  and 
  

   fro, 
  from 
  point 
  to 
  point, 
  within 
  that 
  region. 
  We 
  adopted 
  it 
  chiefly 
  to 
  

   avoid 
  circumlocution, 
  and 
  explained 
  it 
  to 
  avoid 
  confusion. 
  The 
  neglect; 
  

   to 
  distinguish 
  between 
  such 
  movements 
  and 
  real 
  migrations 
  has 
  often 
  led 
  

  

  175 
  Ritter 
  Heusckreckenplage 
  19, 
  Labat, 
  Relat 
  de 
  1' 
  Afrique, 
  Occ. 
  2, 
  176. 
  

  

  176 
  Ex. 
  X. 
  

  

  171 
  Visit 
  to 
  Ganibora, 
  Purclias, 
  ii 
  1046. 
  

   lT 
  *Travels 
  in 
  Arabia, 
  &c, 
  Transl. 
  ii 
  334, 
  &c 
  

   tr? 
  Reise 
  nach 
  Paraguay, 
  p. 
  420. 
  

  

  