﻿62 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  tine 
  Bepublic 
  is 
  distinct 
  ; 
  nor 
  can 
  we 
  find 
  any 
  reason 
  for 
  believing 
  that 
  

   it 
  is 
  found 
  in 
  South 
  Africa. 
  

  

  We 
  base 
  our 
  conclusions, 
  therefore, 
  on 
  a 
  careful 
  study 
  of 
  all 
  the 
  evi- 
  

   dence, 
  making 
  the 
  fact 
  of 
  migration 
  an 
  essential 
  requisite. 
  Proceeding 
  

   upon 
  this 
  basis, 
  let 
  us 
  see 
  what 
  conclusion 
  we 
  shall 
  reach 
  in 
  reference 
  to 
  

   the 
  three 
  chief 
  locusts 
  of 
  the 
  eastern 
  continent 
  — 
  P. 
  migratorius, 
  A. 
  pere- 
  

   grinum, 
  and 
  G. 
  italicus. 
  

  

  To 
  determine 
  what 
  is 
  the 
  permanent 
  home 
  of 
  a 
  migratory 
  species 
  we 
  

   have 
  to 
  rely 
  chiefly 
  upon 
  the 
  following 
  data 
  : 
  1st. 
  The 
  fact 
  that 
  the 
  

   species 
  has 
  been 
  observed 
  for 
  a 
  series 
  of 
  years 
  inhabiting 
  and 
  reproduc- 
  

   ing 
  itself 
  in 
  a 
  given 
  area, 
  which 
  is 
  the 
  best 
  possible 
  evidence. 
  2d. 
  Where 
  

   no 
  such 
  data 
  have 
  been 
  obtained, 
  the 
  next 
  best 
  means 
  of 
  determining 
  this 
  

   point 
  is 
  to 
  trace 
  back 
  the 
  lines 
  of 
  migration 
  to 
  the 
  point 
  of 
  departure. 
  

   But 
  in 
  attempting 
  to 
  follow 
  out 
  the 
  latter 
  method 
  caution 
  is 
  necessary 
  

   lest 
  we 
  are 
  led 
  astray 
  by 
  exceptional 
  cases. 
  For 
  illustration, 
  in 
  the 
  great 
  

   invasion 
  of 
  Europe 
  in 
  1747-'50 
  it 
  is 
  asserted 
  by 
  the 
  best 
  authority 
  that 
  

   the 
  locusts 
  came 
  from 
  Turkey 
  into 
  Wallachia, 
  Moldavia, 
  Transylvania, 
  and 
  

   Hungary; 
  that 
  in 
  1749 
  they 
  passed 
  from 
  thence 
  into 
  Austria 
  and 
  Bava- 
  

   ria, 
  and 
  in 
  1750 
  reached 
  Brandenburg. 
  The 
  assumption 
  that 
  Austria 
  

   and 
  Bavaria 
  were 
  native 
  habitats 
  because 
  the 
  brood 
  that 
  proceeded 
  to 
  

   Brandenburg 
  originated 
  there 
  would 
  have 
  been 
  an 
  error, 
  as 
  these 
  locali- 
  

   ties 
  were 
  but 
  stopping 
  places 
  in 
  their 
  western 
  progress. 
  Just 
  as 
  well 
  

   might 
  the 
  people 
  of 
  Nebraska 
  conclude 
  the 
  home 
  of 
  spretus 
  is 
  in 
  the 
  

   south 
  because 
  swarms 
  were 
  observed 
  coming 
  from 
  that 
  direction 
  in 
  1875 
  

   and 
  1877, 
  when, 
  in 
  fact, 
  they 
  were 
  the 
  resulting 
  broods 
  of 
  the 
  swarms 
  of 
  

   the 
  preceding 
  years 
  which 
  had 
  passed 
  southward. 
  Kefferstein 
  asserts 
  

   that 
  no 
  existing 
  observations 
  would 
  enable 
  any 
  one 
  to 
  follow 
  any 
  locust 
  

   swarm 
  back 
  from 
  Germany 
  into 
  Tartary, 
  and 
  consequently 
  concluded 
  

   that 
  the 
  hordes 
  originated 
  in 
  the 
  vicinity 
  of 
  the 
  places 
  where 
  they 
  were 
  

   observed. 
  Even 
  those 
  observed 
  in 
  England 
  were 
  believed 
  by 
  him 
  to 
  

   have 
  originated 
  in 
  England. 
  Schrank 
  was 
  also 
  of 
  this 
  opinion. 
  162 
  

   Yet 
  all 
  the 
  data 
  which 
  Kefferstein 
  presents 
  in 
  reference 
  to 
  the 
  history 
  of 
  

   their 
  migrations 
  in 
  Europe, 
  so 
  far 
  as 
  P. 
  migratorius 
  is 
  concerned, 
  show 
  

   that 
  they 
  proceeded 
  from 
  points 
  eastward 
  of 
  the 
  places 
  visited. 
  

  

  That 
  there 
  is 
  a 
  large 
  amount 
  of 
  testimony 
  showing 
  that 
  P. 
  migratorius 
  

   is 
  indiginous 
  in 
  a 
  great 
  part 
  of 
  Europe 
  is 
  true. 
  But 
  with 
  the 
  exception 
  

   of 
  one 
  or 
  two 
  witnesses 
  there 
  is 
  a 
  failure 
  to 
  distinguish 
  between 
  this 
  

   species 
  and 
  P. 
  cinerascens. 
  But 
  without 
  stopping 
  to 
  discuss 
  this 
  point, 
  

   which 
  is 
  not 
  essential 
  to 
  the 
  object 
  we 
  have 
  in 
  view, 
  we 
  may 
  add 
  that 
  

   Koppen's 
  own 
  conclusion, 
  shown 
  by 
  the 
  limits 
  of 
  permanent 
  distribution 
  

   he 
  draws, 
  contradicts 
  the 
  larger 
  part 
  of 
  this 
  testimony 
  which 
  relates 
  to 
  

   points 
  north 
  of 
  his 
  line. 
  According 
  to 
  Koppen, 
  great 
  mountain 
  chains 
  

   are 
  powerful 
  obstacles 
  to 
  the 
  diffusion 
  of 
  this 
  species, 
  and 
  that 
  it 
  is 
  rare 
  

   in 
  the 
  southwest 
  of 
  Europe 
  or 
  northwest 
  of 
  Africa 
  where 
  it 
  is 
  almost 
  

   completely 
  replaced 
  by 
  other 
  species, 
  i. 
  e., 
  C. 
  italicus 
  in 
  Spain, 
  Italy, 
  and 
  

  

  162 
  Fauna 
  Boica, 
  Ed. 
  2, 
  a. 
  i, 
  p. 
  35. 
  

  

  