﻿RELATION 
  OF 
  TEMPERATURE 
  TO 
  DEVELOPMENT 
  OF 
  THE 
  EGGS. 
  139 
  

  

  and 
  hatched 
  April 
  25 
  to 
  May 
  12, 
  1877. 
  We 
  will 
  therefore 
  select 
  as 
  our 
  

   dates 
  July 
  25, 
  1876, 
  and 
  April 
  30, 
  1877. 
  

  

  Months. 
  

  

  July 
  

  

  August 
  

  

  September 
  . 
  

   October 
  — 
  

   November 
  . 
  

   December 
  . 
  

   January 
  . 
  . 
  . 
  

   February 
  . 
  . 
  

  

  March 
  

  

  April 
  

  

  Total 
  

  

  °1S 
  

  

  SB'S 
  

  

  •° 
  » 
  a 
  

  

  a£co 
  

   £13 
  Bio 
  

  

  162 
  

  

  O 
  e8 
  

  

  •g- 
  

  

  1G8 
  

   744 
  

   638 
  

   450 
  

   154 
  

  

  28 
  

   

  

  96 
  

   150 
  

   264 
  

  

  ili 
  

  

  2,692 
  

  

  Pi 
  

  

  115 
  

  

  1* 
  

  

  168 
  

  

  682 
  

  

  448 
  

  

  253 
  

  

  30 
  

  

  4 
  

  

  

  

  

  

  42 
  

  

  144 
  

  

  1,771 
  

  

  It 
  is 
  true 
  Professor 
  Abbe's 
  calculations 
  lead 
  him 
  to 
  fix 
  upon 
  April 
  30 
  

   as 
  the 
  time 
  for 
  hatching 
  to 
  begin 
  at 
  this 
  point, 
  but 
  this 
  is 
  upon 
  the 
  

   assumption 
  the 
  eggs 
  are 
  deposited 
  about 
  September 
  1, 
  when, 
  in 
  fact, 
  

   they 
  were 
  deposited 
  in 
  1876 
  by 
  the 
  25th 
  of 
  July. 
  If 
  we 
  take 
  his 
  work- 
  

   ing 
  basis, 
  that 
  is, 
  1,440 
  hours 
  at 
  60°, 
  the 
  hatching 
  in 
  this 
  case 
  should 
  

   have 
  taken 
  place 
  in 
  October 
  ; 
  with 
  50° 
  and 
  1,560 
  hours 
  as 
  the 
  basis, 
  it 
  

   should 
  have 
  occurred 
  in 
  November. 
  

  

  Another 
  fact 
  is 
  revealed 
  by 
  comparing 
  the 
  results 
  of 
  the 
  two 
  places 
  

   mentioned. 
  Hall 
  County 
  and 
  North 
  Platte, 
  in 
  the 
  same 
  latitude, 
  simi- 
  

   larly 
  situated 
  in 
  the 
  same 
  valley 
  and 
  not 
  very 
  far 
  apart, 
  present 
  a 
  wide 
  

   difference 
  in 
  the 
  number 
  of 
  hours 
  required 
  to 
  hatch 
  the 
  eggs. 
  At 
  a 
  

   temperature 
  of 
  60° 
  -f 
  it 
  required 
  1,228 
  hours 
  in 
  one 
  place, 
  and 
  1,771 
  at 
  

   the 
  other 
  ; 
  at 
  50° 
  -f 
  it 
  required 
  2,012 
  at 
  one 
  place, 
  and 
  2,692 
  at 
  the 
  other, 
  

   both 
  calculated 
  on 
  precisely 
  the 
  same 
  basis. 
  

  

  At 
  North 
  Platte, 
  taking 
  50° 
  as 
  a 
  minimum, 
  it 
  required 
  2,692 
  hours, 
  

   1,771 
  of 
  them 
  60 
  o 
  +, 
  to 
  hatch 
  the 
  eggs 
  ; 
  or, 
  to 
  be 
  exact, 
  as 
  in 
  the 
  former 
  

   case, 
  921 
  hours 
  between 
  50° 
  and 
  60° 
  -f- 
  1,411 
  hours 
  between 
  60° 
  and 
  

   75°+ 
  360 
  hours 
  above 
  75°. 
  

  

  As 
  a 
  third 
  example, 
  we 
  select 
  Moorhead, 
  in 
  Clay 
  County, 
  Minnesota, 
  

   where 
  the 
  eggs 
  were 
  deposited 
  July 
  20 
  to 
  August 
  20, 
  1876, 
  and 
  hatched 
  

   May 
  15 
  to 
  30, 
  1877. 
  We 
  take, 
  as 
  the 
  dates 
  to 
  be 
  used, 
  August 
  1, 
  1876, 
  

   and 
  May 
  22, 
  1877, 
  and 
  use 
  the 
  meteorological 
  record 
  of 
  Breckenridge,. 
  

   which 
  is 
  in 
  the 
  same 
  level 
  valley, 
  and 
  but 
  a 
  short 
  distance 
  away. 
  

  

  Months. 
  

  

  August 
  

  

  September 
  . 
  

  

  October 
  

  

  November 
  . 
  

   December 
  . 
  

   January 
  . 
  . 
  . 
  

   February 
  . 
  . 
  

   March 
  

  

  Ma 
  

  

  ay 
  

  

  Total 
  

  

  gas 
  

   •s 
  *> 
  a 
  

  

  ill 
  

  

  713 
  

  

  504 
  

  

  192 
  

  

  16 
  

  

  

  

  

  

  4 
  

  

  

  

  152 
  

  

  252 
  

  

  »•« 
  + 
  

  

  eso 
  

  

  gas 
  

  

  31 
  

   24 
  

   7 
  

   1 
  

   

   

   

   

  

  

  10 
  

  

  118 
  I 
  j 
  1,833 
  

  

  336 
  

   70 
  

   6 
  

   

   

   

   

   54 
  

   190 
  

  

  1,276 
  

  

  