﻿DESCRIPTIONS 
  OF 
  MOVING 
  SWARMS. 
  95 
  

  

  ing 
  forward 
  in 
  the 
  same 
  way 
  ; 
  a 
  movement 
  which 
  the 
  writer 
  of 
  this 
  chap- 
  

   ter 
  has 
  observed 
  on 
  a 
  small 
  scale. 
  

   Denon, 
  192 
  speaking 
  of 
  a 
  flight 
  he 
  observed, 
  says: 
  

  

  Information 
  was 
  brought 
  that 
  the 
  plain 
  was 
  covered 
  with 
  birds, 
  which 
  traveled 
  in 
  

   close 
  phalanxes 
  and 
  descended 
  from 
  the 
  east 
  to 
  the 
  west. 
  From 
  a 
  distance 
  they 
  actually 
  

   saw 
  that 
  the 
  fields 
  seemed 
  to 
  roll 
  along 
  the 
  plain 
  in 
  the 
  direction 
  mentioned. 
  Instead 
  

   of 
  birds, 
  they 
  found 
  a 
  cloud 
  of 
  locusts, 
  who 
  only 
  skimmed 
  along 
  the 
  land, 
  stopping 
  at 
  

   every 
  blade 
  of 
  corn 
  to 
  devour 
  it 
  and 
  then 
  flying 
  to 
  fresh 
  prey. 
  

  

  The 
  following 
  description 
  of 
  their 
  movement 
  by 
  the 
  traveler 
  Anders- 
  

   son 
  is 
  worth 
  repeating 
  l93 
  : 
  

  

  The 
  several 
  columns 
  that 
  crossed 
  our 
  path 
  in 
  the 
  course 
  of 
  the 
  day 
  must 
  each 
  have 
  

   been 
  many 
  miles 
  in 
  length 
  and 
  breadth. 
  The 
  noise 
  of 
  their 
  wings 
  was 
  very 
  great, 
  

   not 
  unlike 
  that 
  caused 
  by 
  a 
  gale 
  of 
  wind 
  whistling 
  through 
  the 
  shrouds 
  of 
  a 
  ship 
  at 
  

   anchor. 
  It 
  was 
  interesting 
  to 
  witness 
  at 
  a 
  distance 
  the 
  various 
  shapes 
  and 
  forms 
  that 
  

   these 
  columns 
  assumed, 
  more 
  especially 
  when 
  crossing 
  mountain 
  ranges. 
  At 
  one 
  time 
  

   they 
  would 
  rise 
  abruptly 
  in 
  a 
  compact 
  body, 
  as 
  if 
  propelled 
  by 
  a 
  strong 
  gust 
  of 
  wind; 
  

   then, 
  suddenly 
  sinking, 
  they 
  would 
  disperse 
  into 
  smaller 
  battalions, 
  not 
  unlike 
  vapors 
  

   floating 
  about 
  a 
  hillside 
  at 
  early 
  morn, 
  and 
  when 
  slightly 
  agitated 
  by 
  the 
  breeze 
  ; 
  or 
  

   they 
  would 
  resemble 
  huge 
  columns 
  of 
  sand 
  or 
  smoke, 
  changing 
  every 
  minute 
  their 
  

   shape 
  and 
  evolutions. 
  

  

  During 
  their 
  flight 
  numbers 
  were 
  constantly 
  alighting 
  ; 
  an 
  action 
  which 
  has 
  not 
  

   inaptly 
  been 
  compared 
  to 
  the 
  falling 
  of 
  large 
  snowflakes. 
  

  

  The 
  Italian 
  author 
  Lucretiis, 
  from 
  whose 
  paper 
  we 
  have 
  already 
  fre- 
  

   quently 
  quoted, 
  makes 
  the 
  following 
  statement 
  in 
  reference 
  to 
  their 
  

   movements 
  : 
  

  

  Upon 
  the 
  emigration 
  of 
  locusts, 
  certain 
  circumstances, 
  as 
  common 
  as 
  they 
  are 
  un- 
  

   heeded, 
  merit 
  the 
  attention 
  of 
  the 
  observer. 
  Their 
  flight 
  is 
  more 
  certain, 
  and 
  at 
  a 
  

   greater 
  altitude, 
  whenever 
  the 
  atmosphere 
  is 
  of 
  a 
  heated 
  temperature, 
  and 
  the 
  air 
  

   clear 
  and 
  calm 
  (?). 
  On 
  the 
  other 
  hand, 
  when 
  the 
  atmosphere 
  is 
  charged 
  with 
  mist 
  or 
  

   with 
  rain, 
  or 
  pervaded 
  by 
  a 
  chilly 
  element, 
  or 
  even 
  about 
  the 
  rising 
  or 
  the 
  setting 
  of 
  

   the 
  sun, 
  they 
  move 
  more 
  slowly, 
  exhibiting 
  a 
  certain 
  rigidity, 
  moving 
  their 
  wings 
  with 
  

   ■difficulty, 
  and 
  not 
  rising 
  to 
  any 
  great 
  height. 
  And 
  when 
  they 
  attempt 
  to 
  continue 
  

   their 
  raids 
  in 
  a 
  rainy 
  season, 
  or 
  one 
  tending 
  to 
  cold, 
  they 
  begin 
  by 
  agitating 
  their 
  

   wings 
  and 
  exerting 
  all 
  their 
  strength 
  to 
  rise 
  ; 
  but 
  not 
  finding 
  themselves 
  in 
  a 
  condi- 
  

   tion 
  to 
  sustain 
  a 
  long 
  journey, 
  they 
  at 
  first 
  droop, 
  and 
  then 
  fall 
  precipitately 
  to 
  the 
  

   ground, 
  and 
  are 
  compelled 
  to 
  continue 
  their 
  journey 
  on 
  foot. 
  

  

  Bowles, 
  194 
  who 
  believes 
  the 
  chief 
  cause 
  of 
  their 
  migration 
  is 
  the 
  flight 
  

   of 
  the 
  females 
  to 
  avoid 
  the 
  importunities 
  of 
  the 
  males, 
  says 
  : 
  

  

  In 
  their 
  efforts 
  to 
  escape 
  they 
  begin 
  to 
  rise 
  little 
  by 
  little 
  into 
  the 
  air, 
  and 
  finally 
  to 
  

   the 
  height 
  of 
  400 
  or 
  500 
  feet, 
  forming 
  a 
  cloud 
  which 
  intercepts 
  the 
  rays 
  of 
  the 
  sun. 
  

   The 
  clear 
  and 
  serene 
  sky 
  of 
  Spain 
  is 
  obscured 
  and 
  becomes 
  in 
  the 
  midst 
  of 
  summer 
  

   more 
  dark 
  and 
  gloomy 
  than 
  that 
  of 
  Germany 
  in 
  spring. 
  The 
  rustling 
  of 
  so 
  many 
  mill- 
  

   ions 
  of 
  wings 
  forms 
  a 
  dull 
  roar 
  similar 
  to 
  that 
  which 
  a 
  sudden 
  blast 
  of 
  wind 
  produces 
  

   in 
  a 
  forest 
  full 
  of 
  leafy 
  trees. 
  The 
  route 
  which 
  the 
  first 
  formidable 
  swarm 
  takes 
  always 
  

   follows 
  the 
  wind, 
  and 
  this 
  first 
  flight 
  is 
  usually 
  prolonged 
  about 
  two 
  leagues, 
  but 
  if 
  

   the 
  weather 
  is 
  calm 
  and 
  serene 
  the 
  length 
  of 
  their 
  flight 
  is 
  less. 
  In 
  these 
  fatal 
  pauses 
  

   the 
  locusts 
  commit 
  the 
  most 
  frightful 
  ravages. 
  By 
  their 
  exquisite 
  sensibility 
  to 
  odors 
  

   they 
  scent 
  from 
  a 
  great 
  height 
  in 
  the 
  air 
  a 
  field 
  of 
  grain 
  or 
  a 
  garden. 
  I 
  have 
  seen 
  

   them 
  turn 
  from 
  the 
  course 
  of 
  their 
  march 
  more 
  than 
  a 
  half 
  a 
  league 
  obliquely 
  to 
  de- 
  

  

  192 
  Travels 
  in 
  Upper 
  and 
  Lower 
  Egypt, 
  Eng. 
  Trans. 
  

  

  193 
  Lake 
  ^gami, 
  282. 
  

  

  194 
  Introduzione 
  alia 
  Storia 
  Xat. 
  et 
  Geog., 
  fisica 
  Spagna, 
  T. 
  2, 
  pp. 
  1-24. 
  

  

  