﻿IV 
  TABLE 
  OF 
  CONTENTS 
  

  

  Facts 
  concerning 
  and 
  laws 
  governing 
  the 
  migrations 
  of 
  locusts 
  in 
  

   all 
  countries— 
  Continued. 
  

  

  not 
  governed 
  by 
  laws 
  of 
  periodicity, 
  55, 
  56— 
  Permanent 
  breeding 
  grounds 
  of 
  

   locusts, 
  56, 
  57— 
  Their 
  geographical 
  distribution, 
  58— 
  Caloptenus 
  spretus 
  not 
  

   in 
  Mexico, 
  58— 
  Migratory 
  locusts 
  in 
  Yucatan 
  and 
  the 
  West 
  Indies, 
  58, 
  59— 
  

   in 
  Nicaragua, 
  59— 
  Geographical 
  limits 
  of 
  Caloptenus 
  spretus, 
  59— 
  of 
  Pachy- 
  

   tylus 
  migratorius, 
  59, 
  60— 
  Difficulty 
  of 
  determining 
  species, 
  60, 
  61— 
  Defini- 
  

   tion 
  of 
  permanent 
  home 
  of 
  migratory 
  locusts, 
  62— 
  Range 
  of 
  Pachytylus 
  

   migratorius, 
  62, 
  63— 
  of 
  Acridium 
  peregrinum, 
  63, 
  64 
  — 
  Comparison 
  with 
  the 
  

   laws 
  of 
  geographical 
  zoology, 
  65, 
  66— 
  Meeting 
  point 
  of 
  three 
  sub-regions, 
  

   67 
  — 
  Each 
  species 
  has 
  its 
  permanent 
  breeding 
  ground, 
  68 
  — 
  General 
  charac- 
  

   ter 
  of 
  the 
  permanent 
  breeding 
  grounds, 
  68, 
  69 
  — 
  Breeding 
  ground 
  of 
  Calop- 
  

   tenus 
  italicus, 
  69 
  — 
  of 
  Pachytylus 
  migratorius, 
  69, 
  70 
  — 
  of 
  Acridium 
  peregrinum, 
  

   70 
  — 
  of 
  Caloptenus 
  spretus, 
  70, 
  71. 
  

  

  CHAPTER 
  IV. 
  

   Habits 
  and 
  characteristics 
  of 
  locusts 
  in 
  all 
  countries 
  within 
  their 
  

   areas 
  of 
  permanent 
  distribution, 
  so 
  far 
  as 
  these 
  relate 
  to 
  their 
  

   movements 
  

  

  Caloptenus 
  spretus 
  always 
  migratory, 
  72, 
  73— 
  Flights 
  of 
  C. 
  spretus, 
  73, 
  74— 
  

   Invading 
  swarms 
  come 
  from 
  northwest, 
  74,75 
  — 
  Other 
  opinions 
  eliminated, 
  

   75, 
  76— 
  Swarms 
  in 
  1875 
  and 
  1876, 
  76, 
  77— 
  Direction 
  of 
  returning 
  swarms 
  of 
  

   C. 
  spretus, 
  78— 
  of 
  other 
  migratory 
  locusts, 
  78, 
  79— 
  Direction 
  of 
  local 
  nights, 
  

   79-81— 
  Returning 
  swarms 
  do 
  little 
  injury, 
  81, 
  82— 
  Distance 
  to 
  which 
  

   swarms 
  may 
  migrate, 
  82-84— 
  Length 
  of 
  a 
  single 
  flight, 
  84, 
  85— 
  Swarms 
  

   able 
  to 
  cross 
  large 
  bodies 
  of 
  water, 
  85, 
  86— 
  Swarms 
  carried 
  far 
  by 
  winds, 
  

   86, 
  87— 
  The 
  mode 
  of 
  flight, 
  87— 
  Position 
  of 
  the 
  locust 
  while 
  flying, 
  87, 
  88— 
  

   Locusts 
  flying 
  with 
  the 
  wind, 
  88, 
  89 
  — 
  Method 
  of 
  falling 
  of 
  swarms, 
  89 
  — 
  

   Formation 
  of 
  swarms, 
  89-91— 
  Movements 
  of 
  swarms 
  of 
  C. 
  spretus, 
  as 
  re- 
  

   ported 
  by 
  Dr. 
  Child, 
  91-93— 
  Other 
  reports, 
  94— 
  Movements 
  of 
  swarms 
  in 
  

   other 
  countries, 
  95-96— 
  Swarms 
  usually 
  alight 
  at 
  night, 
  96, 
  97— 
  The 
  height 
  

   at 
  which 
  swarms 
  move, 
  98-100— 
  Different 
  directions 
  of 
  swarms 
  at 
  the 
  

   same 
  time 
  and 
  place, 
  100— 
  Fall 
  of 
  locusts 
  into 
  the 
  sea, 
  100-102— 
  Great 
  

   flying 
  power 
  of 
  locusts, 
  102— 
  General 
  causes 
  of 
  migration, 
  103— 
  Excessive 
  

   numbers, 
  103, 
  104— 
  Want 
  of 
  food, 
  104— 
  Excessive 
  heat, 
  105— 
  Dry 
  condi- 
  

   tion 
  of 
  the 
  atmosphere, 
  105, 
  106— 
  Arid 
  condition 
  of 
  the 
  mountain 
  region, 
  

   106, 
  107— 
  Immediate 
  causes 
  of 
  migration, 
  107, 
  108. 
  

  

  CHAPTER 
  V. 
  

   Influence 
  of 
  meteorological 
  conditions 
  on 
  the 
  development 
  and 
  

   migrations 
  of 
  locusts 
  « 
  

  

  Influence 
  of 
  heat 
  and 
  dryness, 
  109, 
  110— 
  Packard's 
  table 
  of 
  locust 
  years, 
  

   111, 
  112— 
  Table 
  of 
  rainfalls 
  for 
  1860 
  to 
  1866, 
  112— 
  Influence 
  of 
  the 
  rainfall, 
  

   especially 
  in 
  1864, 
  112, 
  113— 
  Average 
  monthly 
  temperature 
  for 
  1864 
  and 
  

   1866, 
  113-115— 
  Rainfall 
  of 
  the 
  years 
  1863 
  to 
  1867, 
  116— 
  Temperature 
  of 
  the 
  

   years 
  1863 
  to 
  1867, 
  117— 
  Extreme 
  variations 
  of 
  monthly 
  mean 
  temperature 
  

   from 
  1863 
  to 
  1867, 
  118, 
  119— 
  Monthly 
  and 
  annual 
  mean 
  temperature 
  from 
  

   1872 
  to 
  1876, 
  119-121— 
  Monthly 
  and 
  annual 
  rainfall 
  from 
  1872 
  to 
  1878, 
  

   122-124— 
  Extreme 
  fluctuations 
  between 
  monthly 
  mean 
  temperature, 
  

   125, 
  126 
  — 
  Greatest 
  variations 
  between 
  monthly 
  mean 
  temperatures, 
  126 
  — 
  

   Variations 
  of 
  temperature 
  between 
  mouths 
  of 
  consecutive 
  years, 
  127, 
  T2^— 
  

   Daily 
  temperature 
  at 
  Fort 
  Sully 
  from 
  1872 
  to 
  1875, 
  129-134— 
  Relation 
  of 
  

   temperature 
  to 
  the 
  development 
  of 
  the 
  eggs, 
  135, 
  136— 
  Professor 
  Riley's 
  

   experiments, 
  137— 
  Professor 
  Abbe's 
  theory 
  on 
  the 
  subject 
  discussed, 
  

   137-140— 
  Table 
  showing 
  temperature 
  and 
  direction 
  and 
  velocity 
  of 
  wind 
  

   at 
  Western 
  stations, 
  141-154— 
  Relation 
  of 
  temperature 
  and 
  winds 
  to 
  locust 
  

   flights, 
  155. 
  

  

  