﻿EFFECTS 
  OF 
  VARIATION 
  IN 
  TEMPERATURE 
  ON 
  THE 
  EGGS. 
  127 
  

  

  Precisely 
  the 
  same 
  rule 
  holds 
  good 
  here 
  as 
  in 
  the 
  preceding 
  table. 
  The 
  

   ♦chief 
  variations 
  are 
  in 
  the 
  months 
  of 
  December, 
  January, 
  February 
  and 
  

   March. 
  

  

  If 
  the 
  excessive 
  increase 
  of 
  locusts 
  depends 
  to 
  any 
  considerable 
  degree 
  

   upon 
  the 
  temperature, 
  and 
  this 
  excessive 
  increase 
  is 
  the 
  exception 
  and 
  

   not 
  the 
  rule, 
  then 
  we 
  must 
  seek 
  for 
  the 
  cause 
  in 
  the 
  abnormal 
  conditions 
  

   of 
  the 
  temperature. 
  These 
  we 
  see 
  from 
  the 
  foregoing 
  table 
  are 
  found 
  

   chiefly 
  in 
  the 
  winter 
  of 
  the 
  year, 
  the 
  variation 
  in 
  the 
  means 
  of 
  the 
  sum- 
  

   mer 
  months 
  being 
  comparatively 
  unimportant. 
  

  

  The 
  condition 
  as 
  to 
  moisture 
  must, 
  as 
  a 
  matter 
  of 
  course, 
  be 
  combined 
  

   with 
  that 
  of 
  temperature 
  in 
  making 
  the 
  direct 
  application 
  and 
  compar 
  ■ 
  

   ing 
  the 
  locust 
  years 
  with 
  the 
  non 
  -locust 
  years, 
  but. 
  at 
  present 
  we 
  are 
  

   •only 
  endeavoring 
  to 
  ascertain 
  if 
  possible 
  in 
  what 
  respects 
  the 
  records 
  of 
  

   temperature 
  show 
  a 
  variation 
  likely 
  to 
  affect 
  the 
  increase 
  or 
  development 
  

   of 
  the 
  locusts. 
  

  

  As 
  the 
  eggs 
  are 
  deposited 
  before 
  December, 
  and 
  do 
  not 
  hatch 
  out 
  in 
  the 
  

   northern 
  latitudes 
  of 
  their 
  native 
  habitats 
  until 
  after 
  March, 
  it 
  follows 
  

   that 
  if 
  the 
  excessive 
  changes 
  of 
  this 
  part 
  of 
  the 
  year 
  affect 
  them 
  in 
  any 
  

   way 
  it 
  must 
  be 
  by 
  their 
  action 
  upon 
  the 
  eggs. 
  But 
  the 
  facts 
  presented 
  in 
  

   our 
  first 
  report 
  tend 
  to 
  the 
  conclusion 
  that 
  the 
  eggs 
  of 
  C. 
  spretus 
  are 
  

   but 
  little 
  affected 
  by 
  changes 
  of 
  temperature. 
  

  

  There 
  are 
  some 
  other 
  facts 
  presented 
  in 
  Table 
  VI 
  worthy 
  of 
  notice. 
  

  

  If 
  we 
  compare 
  the 
  winters 
  preceding 
  the 
  locust 
  years 
  with 
  those 
  of 
  

   other 
  years, 
  we 
  find 
  that 
  in 
  the 
  series 
  1873 
  to 
  1877, 
  as 
  a 
  rule, 
  the 
  former 
  

   were 
  warmer 
  than 
  the 
  latter. 
  

  

  

  Variations 
  between 
  months 
  of 
  consecutive 
  years. 
  

  

  

  

  Years 
  and 
  stations. 
  

  

  December. 
  

  

  January. 
  

  

  February. 
  

  

  Mean. 
  

  

  1873-74 
  

  

  BRECKENRIPGE. 
  

  

  8.0 
  

   12.8 
  

   18.1 
  

  

  0.1 
  

   23.3 
  

  

  14.9 
  

   26.9 
  

   27.0 
  

   13.7 
  

  

  18.1 
  

   23.0 
  

   27.3 
  

   12.2 
  

  

  11 
  3 
  

  

  2.3 
  

  

  — 
  9.5 
  

   6.3 
  

  

  — 
  0.9 
  

  

  14.7 
  

  

  16.1 
  

   0.1 
  

   18.7 
  

   13.9 
  

  

  15.6 
  

   0.6 
  

   18.9 
  

   13.6 
  

  

  Ifi 
  S 
  

  

  8.0 
  

   -7.9 
  

  

  4.3 
  

   21.5 
  

   27.4 
  

  

  20.3 
  

   4.2 
  

   14.4 
  

   33.4 
  

  

  18.8 
  

  

  2.5 
  

  

  20.7 
  

  

  36.4 
  

  

  • 
  

  

  18.4 
  

   22.4 
  

   13.9 
  

   16.7 
  

  

  2.6 
  

  

  — 
  4.5 
  

  

  17.4 
  

  

  25.5 
  

  

  6.1 
  

  

  1874-75 
  

  

  

  — 
  1.5 
  

  

  1875-76 
  

  

  

  9.6 
  

  

  1876-77 
  

  

  

  6.9 
  

  

  1877-78 
  

  

  1873-74 
  

  

  FORT 
  SULLY. 
  

  

  23.5 
  

   17.1 
  

  

  1874-75 
  

  

  10.4 
  

  

  1875-76 
  

  

  20.0 
  

  

  1876-77 
  

  

  20.3 
  

  

  1873-74 
  

  

  YANKTON. 
  

  

  17.5 
  

  

  1874-75 
  

  

  8.7 
  

  

  1875-76 
  

  

  22.3 
  

  

  1876-77 
  

  

  20.7 
  

  

  1872-73.... 
  

  

  FORT 
  BENTON. 
  

  

  15.4 
  

  

  1873-74.... 
  

  

  

  13! 
  7 
  11. 
  3 
  

   29. 
  6 
  — 
  8. 
  6 
  

   36.8 
  13.9 
  

  

  6. 
  6 
  — 
  3. 
  

  

  8. 
  1 
  1 
  — 
  2. 
  6 
  

  

  — 
  6. 
  3 
  — 
  5. 
  2 
  

  

  —27.4 
  I 
  11.2 
  

  

  15.8 
  

  

  1874-75...: 
  

  

  

  11.6 
  

  

  1875-76.... 
  

  

  

  22.5 
  

  

  1873-74.... 
  

  

  PEMBINA. 
  

  

  2.1 
  

  

  1875-76.... 
  

  

  

  0.3 
  

  

  1876-77 
  .... 
  

  

  

  2.0 
  

  

  1877-78.... 
  

  

  

  2L4 
  

  

  