﻿628 
  REPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  strated 
  tne 
  fact 
  that 
  a 
  temperature 
  of 
  2<^ 
  degrees 
  below 
  zero 
  was 
  fatal 
  

   to 
  them. 
  

  

  The 
  embryos 
  evidently 
  get 
  their 
  growth 
  in 
  the 
  autumn 
  and 
  lie 
  dor- 
  

   mant 
  until 
  the 
  spring 
  before 
  hatching. 
  Mr. 
  Whitman 
  writes 
  me 
  under 
  

   date 
  of 
  February 
  3, 
  1877, 
  from 
  Saint 
  Paul, 
  Minn., 
  " 
  We 
  are 
  inter- 
  

   ested 
  here 
  to 
  know 
  how 
  near 
  the 
  eggs 
  can 
  reach 
  hatching 
  and 
  still 
  

   remain 
  uninjured 
  by 
  feezing, 
  and 
  I 
  have 
  some 
  eggs 
  that 
  were 
  just 
  taken 
  

   from 
  ground 
  frozen 
  solid, 
  and 
  w^ere 
  hatched 
  after 
  being 
  kept 
  moist 
  and 
  

   "warm 
  three 
  days. 
  I 
  heard 
  yesterday 
  of 
  a 
  gentleman 
  who 
  started 
  for 
  

   Chicago 
  with 
  some 
  eggs 
  in 
  his 
  pocket 
  and 
  found 
  them 
  hatched 
  on 
  reach- 
  

   ing 
  that 
  place." 
  

  

  In 
  Missouri, 
  the 
  eggs 
  mostly 
  hatch 
  in 
  the 
  middle 
  of 
  April 
  and 
  early 
  in 
  

   May, 
  while 
  some 
  continue 
  to 
  hatch 
  until 
  June 
  1. 
  The 
  young 
  acquire 
  

   their 
  wings 
  in 
  about 
  seven 
  weeks. 
  — 
  (Riley.) 
  

  

  In 
  Kansas, 
  the 
  eggs 
  hatched 
  the 
  first 
  week 
  in 
  April, 
  and 
  the 
  young 
  

   first 
  became 
  winged 
  May 
  28 
  and 
  29, 
  and 
  began 
  to 
  fly 
  away 
  then, 
  until 
  

   June 
  22. 
  

  

  The 
  locusts 
  leave 
  Kansas, 
  Nebraska, 
  and 
  Missouri 
  about 
  the 
  middle 
  

   of 
  June, 
  and 
  are 
  said 
  to 
  fly 
  in 
  a 
  general 
  northwestward 
  course, 
  while 
  the 
  

   fresh 
  broods 
  from 
  the 
  Rocky 
  Mountains 
  enter 
  these 
  States 
  from 
  about 
  

   July 
  20 
  until 
  the 
  middle 
  or 
  last 
  of 
  September. 
  

  

  In 
  Nebraska, 
  they 
  were 
  fledged 
  in 
  1874, 
  about 
  the 
  7tli 
  of 
  June, 
  and 
  

   then 
  began 
  to 
  fly 
  away, 
  and 
  by 
  the 
  6th 
  of 
  July 
  they 
  had 
  about 
  left 
  the 
  

   State. 
  These 
  dates 
  will 
  approximately 
  apply 
  to 
  Minnesota 
  and 
  Iowa 
  for 
  

   the 
  swarms 
  from 
  the 
  Rock^^ 
  Mountain 
  region. 
  In 
  Iowa 
  the 
  grass- 
  

   hoppers 
  in 
  1874 
  entered 
  the 
  State 
  from 
  the 
  south 
  and 
  west 
  about 
  the 
  

   10th 
  of 
  June; 
  these 
  were 
  the 
  swarms 
  from 
  Kansas, 
  or 
  " 
  probably 
  deflected 
  

   from 
  their 
  usual 
  course 
  by 
  adverse 
  winds." 
  In 
  Minnesota 
  the 
  young 
  

   hatch 
  in 
  April 
  and 
  May, 
  and 
  get 
  their 
  wings 
  and 
  begin 
  to 
  depart 
  about 
  

   July 
  1, 
  the 
  departure 
  becoming 
  general 
  about 
  the 
  10th, 
  and 
  total 
  by 
  the 
  

   end 
  of 
  August. 
  

  

  In 
  Colorado, 
  on 
  the 
  plains 
  at 
  the 
  elevation 
  of 
  Denver, 
  the 
  eggs 
  begin 
  

   sometimes 
  to 
  hatch 
  in 
  March 
  and 
  continue 
  doing 
  so 
  until 
  early 
  in 
  May. 
  

   The 
  locusts 
  acquire 
  their 
  wings 
  and 
  fly 
  off 
  about 
  the 
  first 
  or 
  middle 
  of 
  

   June. 
  The 
  swarms 
  from 
  the 
  north 
  and 
  westward 
  appear 
  about 
  the 
  20th 
  

   of 
  July, 
  and 
  continue 
  to 
  arrive 
  until 
  early 
  in 
  September. 
  Among 
  the 
  

   foot-hills 
  the 
  eggs 
  hatch 
  in 
  May, 
  and 
  at 
  an 
  elevation 
  of 
  8,000 
  or 
  9,000 
  

   feet 
  in 
  June 
  and 
  even 
  July 
  the 
  young 
  in 
  the 
  subalpine 
  elevations 
  among 
  

   the 
  mountains 
  in 
  may 
  cases 
  perishing 
  from 
  the 
  cold 
  before 
  acquiring 
  

   wings. 
  In 
  Dakota, 
  in 
  1874, 
  they 
  became 
  winged 
  during 
  the 
  first 
  week 
  

   in 
  June 
  and 
  disappeared 
  by 
  the 
  middle 
  of 
  July. 
  

  

  It 
  is 
  not 
  generally 
  known 
  that 
  the 
  great 
  powers 
  of 
  flight 
  in 
  the 
  grass- 
  

   hopper 
  as 
  well 
  as 
  most 
  other 
  winged 
  insects 
  is 
  due 
  in 
  part 
  to 
  the 
  pres- 
  

   ence 
  of 
  large 
  air-sacs. 
  These 
  sacs 
  are 
  expansions 
  of 
  the 
  air-tubes 
  

   which 
  ramify 
  throughout 
  the 
  interior 
  of 
  the 
  body. 
  They 
  are 
  found 
  in 
  

   the 
  head 
  and 
  thorax, 
  but 
  are 
  largest 
  (especially 
  in 
  the 
  honey-bee) 
  in 
  the 
  

   base 
  of 
  the 
  hind 
  body. 
  They 
  do 
  not 
  occur 
  in 
  insects 
  which 
  simply 
  

   crawl 
  or 
  walk. 
  In 
  the 
  grasshoppers 
  {Acrydii), 
  most 
  of 
  the 
  transverse 
  

   anastomosing 
  trachese 
  in 
  the 
  abdomen 
  have 
  large 
  air-reservoirs, 
  greatly 
  

   assisting 
  in 
  lightening 
  the 
  body 
  and 
  sustaining 
  it 
  in 
  their 
  long 
  flights. 
  

   It 
  is 
  from 
  their 
  development, 
  probably, 
  in 
  the 
  western 
  locust 
  (I 
  have 
  

   found 
  them 
  well 
  developed 
  in 
  several 
  eastern 
  allied 
  forms) 
  that 
  this 
  in- 
  

   sect 
  is 
  enabled 
  to 
  sail 
  so 
  lightly 
  and 
  easily 
  for 
  hours 
  at 
  a 
  time 
  in 
  the 
  air 
  

   hundreds 
  or 
  even 
  thousands 
  of 
  feet 
  above 
  the 
  ground, 
  as 
  well 
  as 
  to 
  

   spend 
  days, 
  perhaps, 
  in 
  its 
  long 
  flights 
  during 
  the 
  migratory 
  season. 
  

  

  The 
  following 
  valuable 
  notes 
  on 
  the 
  natural 
  history 
  of 
  the 
  grasshop- 
  

  

  