﻿162 
  Mr. 
  F. 
  Merrifield 
  on 
  consjjicuuus 
  effects 
  on 
  

  

  variation, 
  are, 
  as 
  a 
  rule, 
  very 
  decidedly 
  darker 
  than 
  those 
  wliich 
  

   had 
  been 
  finally 
  forced, 
  viz. 
  (g). 
  

  

  (i) 
  Cooling 
  five 
  or 
  six 
  weefcs, 
  followed 
  hy 
  forcing. 
  — 
  Other 
  larvae 
  

   were 
  sleeved, 
  and 
  pupated 
  during 
  the 
  first 
  three 
  weeks 
  of 
  x\ugust. 
  

   They 
  were 
  "cooled" 
  within 
  a 
  few 
  days 
  after 
  pupation, 
  aiid 
  taken 
  

   out 
  of 
  the 
  refrigerator 
  on 
  the 
  14th 
  September, 
  i. 
  e., 
  after 
  about 
  five 
  

   or 
  six 
  weeks, 
  and 
  forced, 
  emerging 
  in 
  fi'ora 
  six 
  to 
  eight 
  days 
  (a 
  few 
  

   of 
  them 
  being 
  taken 
  out 
  of 
  the 
  forcing-box, 
  and 
  replaced 
  in 
  the 
  

   refrigerator 
  when 
  the 
  colouring 
  of 
  the 
  perfect 
  moth 
  began 
  to 
  show 
  ; 
  

   there 
  is 
  no 
  marked 
  difference 
  in 
  those 
  so 
  treated). 
  The 
  colouring 
  

   of 
  all, 
  though 
  dull, 
  is 
  not 
  particularly 
  dark, 
  decidedly 
  not 
  so 
  dark 
  

   as 
  in 
  those 
  of 
  experiment 
  (h). 
  About 
  twenty 
  emerged 
  (rejecting 
  

   cripples). 
  

  

  (j) 
  Cooling 
  five 
  or 
  six 
  weeTis, 
  folloiued 
  hy 
  different 
  tempera- 
  

   tures. 
  — 
  Others, 
  which 
  had 
  been 
  cooled 
  for 
  five 
  or 
  six 
  weeks, 
  were 
  

   afterwards 
  placed 
  at 
  the 
  ordinary 
  outdoor 
  temperature, 
  averaging 
  

   about 
  56° 
  at 
  8 
  a.m., 
  emerging 
  in 
  from 
  12| 
  to 
  21 
  days, 
  some 
  of 
  them 
  

   being 
  on 
  the 
  eighth 
  day 
  placed 
  at 
  the 
  " 
  cooling 
  " 
  temperature, 
  and 
  

   emerging 
  in 
  from 
  2^ 
  to 
  16| 
  days 
  more 
  ; 
  others, 
  being 
  on 
  the 
  eighth 
  

   day 
  forced, 
  and 
  emerging 
  in 
  from 
  2^ 
  to 
  5 
  days 
  afterwards. 
  About 
  

   sixteen 
  emerged 
  (rejecting 
  cripples). 
  Nearly 
  all, 
  except 
  those 
  tlius 
  

   forced, 
  are 
  dark, 
  most 
  very 
  dark 
  ; 
  those 
  cooled 
  being 
  little, 
  if 
  at 
  all, 
  

   darker 
  than 
  those 
  left 
  at 
  the 
  ordinary 
  temperature. 
  

  

  The 
  tendency 
  to 
  dulness, 
  to 
  the 
  blurring 
  of 
  spots 
  and 
  broadening 
  

   of 
  the 
  outer 
  hne, 
  and 
  to 
  the 
  disappearance 
  of 
  the 
  "inner 
  line," 
  is 
  

   to 
  be 
  remarked 
  in 
  most 
  of 
  these 
  included 
  in 
  experiment 
  {j). 
  

  

  Figs. 
  11 
  and 
  12 
  in 
  the 
  illustration 
  represent 
  those 
  that 
  were 
  

   forced 
  without 
  any 
  or 
  very 
  brief 
  previous 
  cooling 
  {g) 
  ; 
  Figs. 
  13 
  and 
  

   14, 
  those 
  cooled 
  several 
  weeks, 
  and 
  then 
  forced 
  (i) 
  ; 
  Figs. 
  15 
  and 
  

   16, 
  those 
  cooled 
  several 
  weeks, 
  and 
  then 
  placed 
  at 
  a 
  low, 
  or 
  mode- 
  

   rately 
  low, 
  temperature 
  till 
  emergence 
  {j). 
  

  

  Effects 
  of 
  Moisture. 
  

  

  Some 
  experiments 
  in 
  1888 
  seemed 
  to 
  show 
  no 
  difference 
  in 
  

   markings 
  or 
  colouring 
  between 
  pupae 
  of 
  illustraria 
  kept 
  moist, 
  

   and 
  others 
  in 
  ii 
  quite 
  dry 
  atmosphere. 
  This 
  year 
  I 
  placed 
  two 
  lots, 
  

   each 
  of 
  six 
  pupae 
  of 
  autumnaria, 
  as 
  soon 
  as 
  they 
  had 
  hardened, 
  on 
  

   sand 
  kept 
  wet 
  in 
  jam-pots 
  rovered 
  with 
  closely-fitting 
  pieces 
  of 
  

   glass, 
  one 
  jam-pot 
  (experiment 
  /.) 
  being 
  placed 
  in 
  the 
  refrigerator 
  

   28 
  days, 
  and 
  then 
  in 
  the 
  room, 
  till 
  the 
  moths 
  emerged, 
  which 
  four 
  

   of 
  them 
  did 
  in 
  from 
  17 
  to 
  19 
  days 
  more 
  (two 
  having 
  died) 
  ; 
  the 
  

   other 
  (experiment 
  I) 
  in 
  the 
  forcing-box, 
  where 
  five 
  out 
  of 
  the 
  six 
  

   emerged 
  in 
  from 
  12 
  to 
  16 
  days. 
  Afterwards 
  (experiment 
  m) 
  fom- 
  

  

  