﻿COMPARISON 
  WITH 
  THE 
  LAWS 
  OF 
  GEOGRAPHICAL 
  ZOOLOGY. 
  65 
  

  

  The 
  universal 
  testimony 
  of 
  those 
  who 
  have 
  witnessed 
  the 
  locust 
  mi- 
  

   grations 
  in 
  Algiers, 
  Morocco, 
  and 
  other 
  portions 
  of 
  Northern 
  Africa 
  

   along 
  the 
  Mediterranean 
  shore 
  .exclusive 
  of 
  Egypt) 
  is 
  that 
  they 
  always 
  

   some 
  from 
  the 
  south. 
  As 
  proof 
  of 
  this, 
  we 
  have 
  only 
  to 
  refer 
  the 
  reader 
  

   to 
  the 
  accounts 
  we 
  have 
  given 
  relating 
  to 
  this 
  section. 
  

  

  In 
  addition 
  to 
  this, 
  the 
  testimony 
  of 
  the 
  French 
  naturalists 
  and 
  recent 
  

   authorities 
  show 
  beyond 
  dispute 
  that 
  the 
  locust 
  of 
  this 
  region 
  is 
  A. 
  pere- 
  

   (jrlnHin. 
  What 
  species 
  are 
  found 
  on 
  the 
  plains 
  of 
  Australia 
  and 
  South- 
  

   ern 
  Africa 
  is 
  yet 
  a 
  matter 
  of 
  doubt, 
  but 
  the 
  facts 
  given 
  are 
  sufficient 
  to 
  

   show 
  that 
  the 
  great 
  intermediate 
  tropical 
  belt 
  is 
  not 
  infested 
  by 
  P. 
  migra- 
  

   tortus 
  as 
  a 
  migratory 
  species. 
  

  

  Before 
  proceeding 
  further 
  in 
  the 
  discussion 
  of 
  this 
  subject, 
  let 
  us 
  see 
  if 
  

   our 
  conclusions 
  will 
  accord 
  more 
  nearly 
  with 
  the 
  laws 
  of 
  geographical 
  

   zoology 
  than 
  the 
  theory 
  attributed 
  to 
  Koppen. 
  If 
  so, 
  then 
  it 
  is 
  fair 
  to 
  

   presume 
  that 
  we 
  are 
  nearer 
  the 
  correct 
  solution 
  of 
  this 
  question 
  than 
  he 
  is. 
  

  

  If 
  the 
  reader 
  will 
  take 
  the 
  trouble 
  to 
  examine 
  Wallace's 
  map 
  of 
  his 
  

   Nearctic 
  Region 
  168 
  and 
  compare 
  the 
  Rocky 
  Mountain 
  subregion 
  (So. 
  2) 
  

   with 
  the 
  line 
  marking 
  the 
  permanent 
  distribution 
  of 
  C. 
  spretus 
  on 
  our 
  

   map 
  he 
  cannot 
  fail 
  to 
  observe 
  the 
  almost 
  exact 
  coincidence 
  of 
  the 
  

   boundaries 
  of 
  the 
  two, 
  the 
  only 
  difference 
  worthy 
  of 
  notice 
  being 
  the 
  south- 
  

   ern 
  extension, 
  which, 
  in 
  reference 
  to 
  C. 
  spretus, 
  is 
  yet 
  an 
  open 
  question. 
  Is 
  

   this 
  purely 
  accidental 
  ; 
  or 
  is 
  it 
  in 
  accordance 
  with 
  the 
  laws 
  of 
  animal 
  

   distribution 
  which 
  have 
  enabled 
  the 
  talented 
  author 
  of 
  that 
  work 
  thus 
  

   to 
  map 
  the 
  boundaries 
  of 
  the 
  faunal 
  region 
  ? 
  

  

  Let 
  him 
  now 
  turn 
  to 
  the 
  map 
  of 
  the 
  Palearctic 
  Region, 
  169 
  . 
  Although 
  

   he 
  will 
  fail 
  to 
  find 
  such 
  exact 
  coincidence 
  between 
  the 
  limits 
  of 
  locust 
  

   distribution 
  and 
  the 
  boundaries 
  of 
  the 
  faunal 
  districts 
  as 
  marked 
  by 
  the 
  

   author, 
  yet 
  a 
  careful 
  examination 
  will 
  show 
  that 
  each 
  migratory 
  locust 
  

   is, 
  after 
  all, 
  confined, 
  as 
  far 
  as 
  its 
  area 
  of 
  permanent 
  distribution 
  is 
  con- 
  

   cerned, 
  to 
  its 
  own 
  faunal 
  district. 
  The 
  reader 
  will 
  observe 
  that 
  in 
  the 
  

   southeast 
  part 
  of 
  subregion 
  1 
  (European) 
  and 
  the 
  southwest 
  of 
  Xo. 
  3 
  

   (Siberian) 
  there 
  is 
  an 
  immense 
  area 
  marked 
  as 
  pasture-land, 
  which 
  ex- 
  

   tends 
  east 
  and 
  west 
  from 
  Hungary 
  to 
  China, 
  embracing 
  within 
  its 
  bounds 
  

   all 
  that 
  section 
  to 
  which 
  the 
  name 
  Tartary, 
  or 
  Tahtary, 
  was 
  applied 
  by 
  

   the 
  early 
  writers 
  and 
  travelers. 
  The 
  northern 
  boundary 
  of 
  this 
  area, 
  as 
  

   mapped 
  by 
  Wallace, 
  corresponds 
  almost 
  exactly 
  with 
  the 
  line 
  of 
  perma- 
  

   nent 
  distribution 
  of 
  P. 
  migrator 
  his 
  as 
  given 
  by 
  Koppen; 
  and 
  we 
  are 
  

   inclined 
  to 
  believe 
  that, 
  with 
  the 
  exception 
  of 
  the 
  debatable 
  ground 
  of 
  

   Asia 
  Minor 
  and 
  Syria 
  (or 
  Asiatic 
  Turkey), 
  the 
  southern 
  and 
  eastern 
  

   limits 
  represent 
  approximately 
  the 
  southern 
  and 
  eastern 
  boundary 
  of 
  

   permanent 
  distribution 
  of 
  this 
  species. 
  

  

  From 
  these 
  broad, 
  grassy 
  plains, 
  or 
  steppes, 
  carried 
  by 
  easterly 
  winds, 
  

   they 
  sweep 
  over 
  Southern 
  and 
  Central 
  Europe, 
  usually 
  along 
  the 
  northern 
  

   shore 
  of 
  the 
  Black 
  Sea, 
  but 
  occasionally 
  from 
  Asia 
  Minor 
  ; 
  the 
  Ukraine 
  

   and 
  the 
  region 
  of 
  the 
  Crimea, 
  occupying 
  the 
  straits 
  or 
  narrows 
  of 
  this 
  

  

  '"Geographical 
  Distribution 
  of 
  Animals, 
  I, 
  p. 
  115. 
  ie9 
  Vol. 
  L., 
  p. 
  181. 
  

  

  O 
  L 
  

  

  