﻿PREFACE. 
  XV 
  

  

  distribution, 
  left 
  incomplete 
  in 
  our 
  former 
  map. 
  He 
  obtained 
  import- 
  

   ant 
  data 
  upon 
  the 
  habits 
  of 
  the 
  locust 
  in 
  that 
  BectiOD 
  and 
  found 
  that 
  

   they 
  had 
  flown 
  in 
  and 
  about 
  Santa 
  Fe* 
  from 
  the 
  north 
  during 
  the 
  years 
  

  

  1865,1808, 
  1874, 
  and 
  1877. 
  and 
  he 
  also 
  traced 
  them 
  into 
  Eastern 
  Arizona. 
  

   Mr. 
  Thomas 
  during 
  this 
  year 
  devoted 
  his 
  time 
  more 
  particularly 
  to 
  the 
  

   meteorological 
  facts 
  bearing 
  upon 
  the 
  increase 
  and 
  development 
  of 
  the 
  

   locust. 
  lie 
  was 
  forced 
  to 
  the 
  conclusion 
  that 
  the 
  meteorological 
  data 
  

   hardly 
  bore 
  out 
  the 
  generally 
  received 
  opinion 
  that 
  heat 
  and 
  dryness 
  art- 
  

   necessary 
  to 
  excessive 
  increase, 
  but 
  that 
  wiuter 
  conditions 
  have 
  greater 
  

   influence 
  than 
  has 
  been 
  suspected. 
  While 
  the 
  data 
  he 
  obtained 
  have 
  

   comparatively 
  little 
  value, 
  therefore, 
  and 
  the 
  annual 
  and 
  monthly 
  means 
  

   were 
  of 
  no 
  value 
  whatever 
  as 
  throwing 
  light 
  on 
  increase 
  and 
  develop- 
  

   ment, 
  the 
  daily 
  records 
  proved 
  most 
  valuable 
  in 
  their 
  bearing 
  on 
  flights. 
  

   In 
  planning 
  this 
  report 
  it 
  was 
  decided 
  to 
  introduce 
  with 
  the 
  more 
  

   practical 
  chapters 
  a 
  few 
  giving 
  the 
  results 
  of 
  some 
  of 
  the 
  purely 
  scien- 
  

   tific 
  work 
  that 
  has 
  grown 
  out 
  of 
  the 
  inquiry. 
  

  

  In 
  Chapter 
  I, 
  Messrs. 
  Packard 
  and 
  Eiley 
  have 
  added 
  to 
  the 
  hitherto 
  

   published 
  chronological 
  history 
  of 
  locust 
  injury 
  by 
  giving 
  data 
  for 
  the 
  

  

  | 
  past 
  and 
  the 
  present 
  year. 
  

  

  In 
  Chapter 
  II, 
  prepared 
  by 
  Mr. 
  Thomas, 
  the 
  subject 
  of 
  the 
  relation 
  

   of 
  the 
  locust 
  and 
  its 
  ravages 
  to 
  agriculture 
  and 
  the 
  settlement 
  of 
  the 
  

   Territories 
  is 
  discussed 
  in 
  all 
  its 
  different 
  bearings. 
  Different 
  plans 
  of 
  

   inducing 
  increase 
  in 
  the 
  purely 
  agricultural 
  rather 
  than 
  the 
  pastoral 
  

   population, 
  the 
  difficulties 
  in 
  the 
  way 
  of 
  successfully 
  burning 
  over 
  the 
  

   locust-infested 
  area, 
  and 
  the 
  non-feasibility 
  of 
  other 
  plans 
  are 
  dwelt 
  

   upon 
  ; 
  and 
  while 
  utter 
  extermination 
  of 
  the 
  pest 
  is 
  out 
  of 
  the 
  question, 
  

   it 
  is 
  clearly 
  shown 
  that 
  the 
  evil 
  may 
  be 
  materially 
  modified, 
  and 
  that 
  

   government 
  action 
  in 
  the 
  matter 
  is 
  warranted 
  because 
  the 
  evil 
  is 
  essen- 
  

   tially 
  a 
  national 
  one. 
  

   In 
  Chapter 
  III, 
  also 
  by 
  Mr. 
  Thomas, 
  a 
  mass 
  of 
  information 
  is 
  brought 
  

  

  [ 
  together 
  in 
  regard 
  to 
  the 
  laws 
  governing 
  the 
  migrations 
  of 
  locusts 
  in 
  

   all 
  countries. 
  It 
  is 
  there 
  showu 
  that 
  the 
  essentially 
  migrating 
  habit 
  is 
  

   confined 
  to 
  about 
  four 
  species, 
  all 
  of 
  them 
  inhabiting 
  and 
  coming 
  from 
  

   treeless, 
  arid, 
  and 
  elevated 
  regions. 
  In 
  a 
  few 
  instances 
  a 
  species 
  which 
  

  

  , 
  is 
  sedentary 
  in 
  one 
  part 
  of 
  a 
  continent 
  becomes 
  migratory 
  in 
  another. 
  

  

  j 
  As 
  in 
  the 
  case 
  of 
  our 
  own 
  species, 
  there 
  are 
  no 
  laws 
  of 
  periodicity 
  gov- 
  

  

  i 
  erning 
  destructive 
  flights, 
  these 
  only 
  occurring 
  at 
  irregular 
  intervals. 
  

   Nevertheless 
  the 
  history 
  of 
  the 
  most 
  noted 
  locust 
  years, 
  both 
  in 
  this 
  

  

  ; 
  country 
  and 
  in 
  Europe, 
  shows 
  a 
  tendency 
  to 
  their 
  recurrence 
  about 
  every 
  

   eleven 
  years. 
  It 
  is 
  also 
  shown 
  that 
  the 
  European 
  and 
  Asiatic 
  species 
  

   have, 
  like 
  our 
  own, 
  areas 
  where 
  they 
  permanently 
  breed, 
  and 
  from 
  which 
  

  

  | 
  they 
  swarm 
  in 
  exceptional 
  years 
  to 
  extend 
  over 
  adjacent 
  regions 
  in 
  

   which 
  they 
  are 
  not 
  found 
  permanently. 
  

  

  Chapter 
  IY, 
  also 
  by 
  Mr. 
  Thomas, 
  treats 
  of 
  the 
  habits 
  and 
  characters 
  

  

  ' 
  of 
  locusts 
  in 
  different 
  countries 
  within 
  their 
  areas 
  of 
  permanent 
  distri- 
  

   bution, 
  especially 
  so 
  far 
  as 
  such 
  areas 
  relate 
  to 
  their 
  movements. 
  The 
  

  

  