﻿136 
  W. 
  A. 
  LAMBORN. 
  

  

  The 
  average 
  number 
  of 
  ova, 
  based 
  on 
  data 
  from 
  8 
  parents, 
  works 
  out 
  at 
  29, 
  the 
  

   maximum 
  number 
  having 
  been 
  49. 
  

  

  Dr. 
  Stanton 
  finds 
  that 
  the 
  ovum 
  does 
  not 
  differ 
  from 
  that 
  of 
  A 
  . 
  kochi. 
  

  

  The 
  ova 
  referred 
  to 
  were 
  laid 
  in 
  one 
  batch, 
  and 
  though 
  several 
  bowls 
  of 
  similar 
  

   water 
  were 
  often 
  provided, 
  almost 
  always 
  in 
  one 
  only. 
  Exceptions 
  were 
  noted 
  

   occasionally 
  with 
  A. 
  hyrcanus 
  and 
  repeatedly 
  with 
  A. 
  tessellatus 
  , 
  which 
  usually 
  

   laid 
  a 
  few 
  ova 
  day 
  by 
  day 
  for 
  five 
  or 
  six 
  days. 
  In 
  only 
  two 
  instances 
  were 
  second 
  large 
  

   batches 
  of 
  ova 
  obtained 
  : 
  one 
  A 
  . 
  hyrcanus 
  laid 
  a 
  batch 
  of 
  45 
  ova 
  during 
  the 
  night 
  of 
  

   21st 
  October 
  and 
  a 
  second 
  batch 
  of 
  79 
  on 
  the 
  following 
  night 
  ; 
  and 
  one 
  A. 
  vagus 
  

   laid 
  a 
  batch 
  of 
  93 
  ova 
  during 
  the 
  night 
  of 
  3rd 
  August 
  and 
  a 
  second 
  batch 
  of 
  180 
  ova 
  

   in 
  the 
  course 
  of 
  the 
  foUowing 
  afternoon. 
  

  

  Infection 
  of 
  Anophelines 
  with 
  the 
  malaria 
  parasite 
  seemed 
  to 
  have 
  no 
  adverse 
  

   influence 
  on 
  oviposition. 
  An 
  A. 
  maculatus, 
  which 
  on 
  dissection 
  later 
  showed 
  eight 
  

   zygotes 
  in 
  its 
  stomach 
  and 
  sporozoites 
  in 
  all 
  the 
  lobes 
  of 
  the 
  salivary 
  glands, 
  afforded 
  

   a 
  large 
  batch 
  of 
  ova 
  from 
  which 
  as 
  many 
  as 
  78 
  offspring 
  were 
  bred 
  up. 
  This 
  

   observation 
  was 
  confirmed 
  by 
  experiment 
  with 
  21 
  other 
  females 
  of 
  this 
  species, 
  all 
  

   of 
  which, 
  though 
  infected, 
  afforded 
  ova 
  that 
  duly 
  hatched 
  out. 
  

  

  The 
  tendency 
  of 
  the 
  ova 
  to 
  drift 
  together 
  by 
  capillary 
  attraction 
  as 
  described 
  for 
  

   British 
  species, 
  and 
  to 
  form 
  triangles, 
  diamonds 
  and 
  other 
  geometrical 
  figures, 
  was 
  

   marked 
  in 
  the 
  case 
  of 
  all 
  species 
  except 
  A 
  . 
  tessellatus. 
  

  

  It 
  has 
  already 
  been 
  remarked 
  that 
  the 
  ova 
  when 
  first 
  laid 
  are 
  white. 
  It 
  was 
  by 
  no 
  

   means 
  unusual, 
  especially 
  with 
  A. 
  aconitus, 
  to 
  find 
  a 
  large 
  percentage 
  of 
  a 
  batch, 
  

   still 
  white, 
  sunk 
  at 
  the 
  bottom 
  of 
  the 
  water, 
  their 
  floats 
  unexpanded 
  ; 
  and 
  parti- 
  

   coloured 
  ova 
  floating 
  among 
  black 
  ones. 
  For 
  instance, 
  of 
  65 
  ova 
  laid 
  b} 
  T 
  an 
  A 
  . 
  aconitus 
  

   40 
  were 
  black 
  in 
  colour 
  and 
  floated, 
  and 
  25 
  white 
  had 
  sunk 
  to 
  the 
  bottom 
  of 
  the 
  bowl. 
  

   None 
  of 
  either 
  batch 
  hatched. 
  Such 
  white 
  ova 
  as 
  had 
  sunk 
  were 
  found 
  to 
  have 
  their 
  

   floats 
  unexpanded. 
  But 
  even 
  brown 
  and 
  black 
  ova, 
  with 
  floats 
  unexpanded, 
  were 
  

   found 
  to 
  have 
  sunk. 
  This 
  was 
  especially 
  the 
  case 
  with 
  those 
  of 
  A 
  . 
  tessellatus. 
  Thus 
  

   28 
  ova, 
  normal 
  in 
  appearance 
  except 
  as 
  to 
  floats, 
  and 
  in 
  another 
  instance 
  88 
  similar 
  

   ova, 
  were 
  found 
  at 
  the 
  bottom 
  of 
  a 
  basin 
  of 
  water. 
  Sometimes 
  floating 
  ova 
  never 
  

   assumed 
  their 
  proper 
  colour 
  and 
  failed 
  to 
  hatch. 
  This 
  was 
  the 
  case, 
  for 
  instance, 
  

   with 
  30 
  white 
  and 
  50 
  brown 
  ova 
  laid 
  by 
  an 
  A 
  . 
  fuliginosus 
  on 
  25th 
  September, 
  and 
  

   with 
  46 
  brown 
  ova 
  laid 
  by 
  an 
  A. 
  aconitus 
  on 
  19th 
  October, 
  and 
  with 
  108 
  brown 
  ova 
  

   laid 
  by 
  an 
  A. 
  hyrcanus 
  on 
  26th 
  October; 
  and 
  such 
  cases 
  were 
  numerous. 
  Whole 
  

   batches 
  of 
  ova, 
  entirely 
  normal 
  in 
  appearance 
  and 
  floating 
  on 
  water, 
  sometimes 
  

   failed 
  to 
  hatch. 
  This 
  was 
  noted 
  quite 
  frequently 
  with 
  those 
  of 
  A. 
  umbrosus, 
  from 
  

   females 
  taken 
  in 
  Kuala 
  Lumpur. 
  Batches 
  of 
  these 
  ova 
  were 
  sometimes 
  kept 
  for 
  

   weeks 
  on 
  the 
  assumption 
  that 
  incubation 
  may 
  be 
  delayed. 
  It 
  was 
  then 
  thought 
  that 
  

   the 
  medium 
  on 
  which 
  they 
  were 
  placed 
  might 
  be 
  unsuitable, 
  but 
  none 
  hatched 
  when 
  

   they 
  were 
  transferred 
  shortly 
  after 
  being 
  laid 
  to 
  rainwater 
  and 
  to 
  water 
  from 
  a 
  

   natural 
  breeding-place. 
  It 
  is 
  not 
  known 
  whether 
  the 
  act 
  of 
  coitus 
  in 
  Anophelines 
  is 
  

   related, 
  as 
  concerns 
  the 
  female, 
  to 
  a 
  meal 
  of 
  blood. 
  If 
  it 
  takes 
  place 
  subsequent 
  to 
  

   such 
  a 
  meal 
  the 
  failure 
  of 
  the 
  ova 
  of 
  A 
  . 
  umbrosus 
  to 
  hatch 
  is 
  explicable 
  on 
  the 
  assumption 
  

   that 
  the 
  virgin 
  females 
  had 
  been 
  compelled 
  to 
  leave 
  their 
  haunts, 
  known 
  to 
  be 
  remote 
  

   from 
  the 
  town, 
  in 
  search 
  of 
  a 
  meal, 
  and 
  had 
  so 
  escaped 
  the 
  attentions 
  of 
  males 
  

   subsequent 
  to 
  it. 
  Infertility 
  of 
  the 
  ova 
  as 
  a 
  cause 
  of 
  failure 
  to 
  hatch 
  is 
  suggested 
  by 
  

   a 
  case 
  in 
  which 
  112 
  ova 
  laid 
  by 
  an 
  A. 
  vagus 
  on 
  5th 
  August 
  all 
  duly 
  afforded 
  larvae, 
  

   whereas 
  of 
  a 
  second 
  batch 
  of 
  107 
  ova 
  (39 
  black 
  and 
  68 
  white) 
  none 
  hatched. 
  

  

  The 
  ova 
  were 
  not 
  always 
  deposited 
  on 
  water. 
  For 
  instance, 
  an 
  A 
  . 
  karwari, 
  enclosed 
  

   in 
  a 
  dry 
  tube 
  plugged 
  with 
  cotton 
  wool, 
  was 
  observed 
  in 
  the 
  middle 
  of 
  the 
  morning 
  

   to 
  be 
  ejecting 
  to 
  a 
  distance 
  white 
  ova, 
  which 
  blackened 
  only 
  on 
  transfer 
  to 
  water, 
  

   hatching 
  in 
  due 
  course. 
  An 
  A. 
  barbirostris 
  deposited 
  in 
  a 
  heap 
  in 
  a 
  dry 
  tube 
  ova 
  

   estimated 
  at 
  56 
  ; 
  these 
  were 
  floated 
  off 
  on 
  water, 
  becoming 
  black 
  two 
  hours 
  later, 
  

   and 
  all 
  eventually 
  hatched. 
  Another 
  A 
  . 
  barbirostris, 
  kept 
  in 
  a 
  glass 
  tube 
  for 
  four 
  days, 
  

  

  