﻿140 
  ■_ 
  W. 
  A. 
  LAMBORN. 
  x 
  

  

  in 
  making 
  its 
  escape, 
  the 
  other 
  2 
  dying 
  in 
  situ. 
  It 
  is 
  therefore- 
  to 
  be 
  presumed 
  that, 
  

   though 
  the 
  ova 
  were 
  at 
  an 
  advanced 
  state 
  of 
  incubation 
  when 
  removed, 
  the 
  progress 
  

   of 
  development 
  was 
  checked, 
  partly 
  or 
  entirely, 
  only 
  by 
  their 
  removal 
  from 
  the 
  water. 
  

  

  The 
  viability 
  of 
  the 
  various 
  ova 
  was 
  found 
  to 
  be 
  very 
  considerably 
  extended 
  

   beyond 
  these 
  limits 
  when 
  they 
  were 
  kept 
  in 
  a 
  thoroughly 
  moist 
  atmosphere. 
  This 
  is 
  

   shown 
  by 
  the 
  following 
  experiments 
  : 
  — 
  

  

  ' 
  Of 
  20 
  ova 
  laid 
  during 
  the 
  night 
  of 
  16th 
  June 
  by 
  an 
  A. 
  vagus, 
  8 
  were 
  left 
  as 
  a 
  controL 
  

   and 
  in 
  due 
  course 
  all 
  afforded 
  larvae 
  between 
  18th 
  and 
  22nd 
  June. 
  The 
  remaining 
  

   12 
  ova 
  were 
  removed 
  at 
  4 
  p.m. 
  on 
  17th 
  June 
  to 
  a 
  Petri 
  dish 
  containing 
  moist 
  blotting 
  

   paper. 
  The 
  dish 
  was 
  unopened 
  for 
  82 
  hours, 
  when, 
  at 
  11.30 
  a.m. 
  on 
  21st 
  June, 
  all 
  

   the 
  ova 
  seemed 
  to 
  be 
  unchanged 
  except 
  one 
  which 
  had 
  yielded 
  a 
  larva 
  that 
  was 
  lying 
  

   close 
  beside 
  its 
  egg-shell. 
  One 
  of 
  the 
  ova 
  was 
  then 
  placed 
  on 
  water 
  and 
  kept 
  under 
  

   observation 
  for 
  several 
  days 
  ; 
  it 
  failed 
  to 
  hatch, 
  as 
  did 
  another 
  placed 
  on 
  water 
  24 
  

   hours 
  later. 
  Five 
  more 
  of 
  the 
  ova 
  still 
  unchanged 
  in 
  appearance 
  were 
  transferred 
  

   to 
  water 
  on 
  23rd 
  June 
  at 
  8 
  a.m. 
  No 
  hatching 
  had 
  taken 
  place 
  24 
  hours 
  later, 
  but 
  of 
  

   the 
  4 
  ova 
  still 
  remaining 
  in 
  the 
  Petri 
  dish, 
  almost 
  seven 
  days 
  after 
  they 
  had 
  been 
  laid, 
  

   2 
  were 
  seen 
  to 
  have 
  their 
  caps 
  open. 
  Both 
  promptly 
  hatched 
  on 
  transfer 
  to 
  water,, 
  

   and 
  a 
  third 
  larva 
  came 
  out 
  from 
  one 
  of 
  the 
  other 
  two 
  eggs 
  later 
  on 
  in 
  the 
  same 
  day. 
  

   There 
  then 
  being 
  every 
  expectation 
  that 
  some 
  of 
  the 
  5 
  ova 
  placed 
  on 
  the 
  water 
  on 
  

   23rd 
  June 
  were 
  still 
  alive, 
  the 
  bowl 
  containing 
  them 
  was 
  at 
  8 
  a.m. 
  on 
  24th 
  June 
  put 
  

   out 
  in 
  the 
  open 
  air 
  in 
  sunlight. 
  At 
  4 
  p.m. 
  1 
  larva 
  was 
  found 
  to 
  have 
  hatched, 
  

   and 
  another 
  ovum, 
  with 
  its 
  terminal 
  cap 
  slightly 
  open, 
  shortly 
  afterwards 
  produced 
  

   a 
  second. 
  The 
  bowl 
  was 
  placed 
  in 
  the 
  sun 
  for 
  several 
  days 
  onwards, 
  but 
  none 
  of 
  

   the 
  3 
  remaining 
  ova 
  hatched. 
  / 
  

  

  One 
  hundred 
  eggs 
  laid 
  by 
  an 
  A. 
  vagus 
  during 
  the 
  night 
  of 
  20th 
  June 
  were 
  left 
  

   on 
  the 
  water 
  for 
  31 
  hours, 
  and 
  then 
  removed 
  to 
  moist 
  filter-paper 
  enclosed 
  in 
  a 
  Petri 
  

   dish. 
  The 
  eggs, 
  examined 
  day 
  by 
  day, 
  showed 
  no 
  change 
  till 
  the 
  fourth 
  day, 
  when 
  

   at 
  10.30 
  a.m. 
  a 
  single 
  egg 
  showed 
  its 
  cap 
  open, 
  and 
  on 
  transfer 
  ,to 
  water 
  the 
  larva 
  

   forthwith 
  wriggled 
  out. 
  Within 
  five 
  minutes 
  every 
  single 
  egg 
  had 
  its 
  cap 
  off. 
  On 
  

   the 
  transfer 
  to 
  water 
  of 
  15, 
  one 
  by 
  one, 
  each 
  produced 
  a 
  larva. 
  Five 
  of 
  the 
  ova 
  

   transferred 
  to 
  water 
  at 
  4 
  p.m. 
  on 
  the 
  same 
  day 
  all 
  hatched 
  at 
  once. 
  With 
  a 
  view 
  to 
  

   testing 
  what 
  length 
  of 
  time 
  larvae 
  partly 
  hatched 
  can 
  survive 
  in 
  a 
  moist 
  atmosphere, 
  

   the 
  remaining 
  ova 
  were 
  transferred 
  at 
  intervals 
  to 
  water. 
  On 
  8th 
  June, 
  at 
  8 
  a.m., 
  

   10 
  ova 
  so 
  transferred 
  all 
  hatched 
  at 
  once, 
  but 
  in 
  the 
  case 
  of 
  18 
  ova 
  transferred 
  24 
  hours 
  

   later 
  a 
  considerable 
  falling 
  off 
  in 
  vitality 
  was 
  found. 
  Three 
  hatched 
  almost 
  at 
  once 
  ; 
  

  

  5 
  after 
  some 
  minutes 
  ; 
  the 
  remaining 
  10 
  completely 
  failed 
  to 
  hatch, 
  but 
  on 
  30th 
  June 
  

   were 
  to 
  be 
  seen 
  with 
  the 
  heads 
  of 
  the 
  larvae 
  presenting, 
  as 
  if 
  these 
  had 
  died 
  in 
  situ, 
  

   having 
  insufficient 
  energy 
  to 
  complete 
  their 
  exit. 
  On 
  30*h 
  June 
  the 
  remainder 
  of 
  the 
  

   ova 
  were 
  transferred 
  to 
  water. 
  No 
  larvae 
  emerged 
  forthwith, 
  though 
  all 
  the 
  ova 
  

   had 
  their 
  caps 
  off 
  ; 
  3 
  only 
  were 
  found 
  hatched 
  24 
  hours 
  later, 
  and 
  these 
  were 
  feeble 
  

   and 
  perished 
  shortly 
  afterwards. 
  

  

  Of 
  248 
  ova 
  laid 
  by 
  an 
  A 
  . 
  vagus 
  56 
  were 
  left 
  on 
  water 
  as 
  a 
  control, 
  and 
  the 
  balance, 
  

   after 
  a 
  possible 
  incubation 
  period 
  of 
  24 
  hours, 
  were 
  placed 
  in 
  a 
  moist 
  Petri 
  dish. 
  

   From 
  this 
  56, 
  removed 
  at 
  the 
  end 
  of 
  90 
  hours, 
  were 
  again 
  transferred 
  to 
  water 
  ; 
  

  

  6 
  hatched 
  out 
  almost 
  at 
  once, 
  and 
  by 
  the 
  end 
  of 
  24 
  hours 
  the 
  larvae 
  were 
  so 
  numerous 
  

   that 
  it 
  was 
  estimated 
  that 
  practically 
  all 
  must 
  have 
  hatched. 
  A 
  second 
  batch 
  of 
  

   the 
  same 
  ova 
  left 
  in 
  a 
  Petri 
  dish 
  for 
  48 
  hours 
  longer, 
  i.e., 
  138 
  hours 
  in 
  all, 
  were 
  then 
  

   restored 
  to 
  water, 
  being 
  then 
  162 
  hours 
  old 
  ; 
  2 
  hatched 
  almost 
  at 
  once, 
  and 
  the 
  

   majority 
  within 
  five 
  minutes. 
  The 
  result 
  was 
  equally 
  good 
  with 
  a 
  third 
  batch 
  of 
  

   80 
  ova 
  left 
  in 
  the 
  moist 
  atmosphere 
  162 
  hours 
  and 
  being 
  then 
  186 
  hours 
  old 
  ; 
  10 
  had 
  

   their 
  caps 
  off 
  ; 
  9 
  of 
  these 
  hatched 
  at 
  once 
  on 
  restoration 
  to 
  water, 
  and 
  it 
  was 
  estimated 
  

   at 
  the 
  end 
  of 
  eight 
  hours 
  that 
  practically 
  all 
  had 
  hatched. 
  

  

  Sixty-nine 
  ova 
  laid 
  by 
  a 
  female 
  A 
  . 
  fuliginosus 
  during 
  the 
  night 
  of 
  5th 
  June 
  were 
  

   divided 
  into 
  two 
  batches, 
  (a) 
  of 
  25 
  as 
  a 
  control, 
  and 
  (b) 
  of 
  44 
  for 
  experimental 
  work. 
  

  

  