﻿BREEDING-PLACES 
  01 
  mi 
  ^NOPHELINES 
  OF 
  MALAYA. 
  II 
  

  

  The 
  newly 
  laid 
  ova 
  of 
  .1. 
  aconitus, 
  for 
  instance, 
  which 
  were 
  tested 
  on 
  tap 
  watei 
  

   and 
  on 
  the 
  water 
  from 
  small 
  muddy 
  pools 
  on 
  unfrequented 
  roads, 
  from 
  the 
  fishpond 
  

   referred 
  to, 
  from 
  the 
  cesspit 
  of 
  a 
  Chinese 
  house, 
  and 
  from 
  a 
  jungle 
  pool, 
  all 
  hatched. 
  

   The 
  ova 
  of 
  A. 
  aconitus 
  and 
  of 
  A. 
  vagus 
  duly 
  hatched 
  when 
  transferred 
  within 
  

   a 
  few 
  hours 
  of 
  oviposition 
  to 
  water 
  which 
  had 
  been 
  thoroughly 
  boiled 
  a 
  lew 
  hours 
  

   previously. 
  

  

  An 
  experiment 
  of 
  some 
  interest 
  consisted 
  in 
  the 
  transfer 
  of 
  67 
  newly 
  laid 
  ova 
  ol 
  

   A. 
  vagus 
  to 
  water 
  in 
  which 
  rice 
  had 
  been 
  boiled 
  a 
  few 
  days 
  previously 
  and 
  which 
  was 
  

   therefore 
  acid 
  and 
  malodorous, 
  the 
  rice 
  fragments 
  forming 
  a 
  culture 
  medium 
  for 
  a 
  

   species 
  of 
  mould. 
  No 
  hatching 
  at 
  all 
  took 
  place, 
  though 
  of 
  25 
  ova 
  of 
  the 
  same 
  batch 
  

   tested 
  as 
  a 
  control 
  on 
  fresh 
  water 
  every 
  single 
  one 
  hatched. 
  Though 
  this 
  medium 
  

   was 
  so 
  unpropitious 
  to 
  this 
  species 
  of 
  Anopheline 
  it 
  turned 
  out 
  to 
  be 
  singularly 
  

   favourable 
  to 
  a 
  species 
  of 
  Ctdex, 
  three 
  rafts 
  of 
  ova 
  deposited 
  thereon 
  affording 
  hundreds 
  

   of 
  larvae 
  which 
  fed 
  up 
  first 
  on 
  the 
  moulds 
  and 
  then 
  on 
  the 
  rice 
  fragments, 
  so 
  that 
  the 
  

   water 
  became 
  clear, 
  and 
  being 
  placed 
  in 
  a 
  light 
  situation 
  developed, 
  at 
  the 
  end 
  of 
  

   about 
  a 
  month, 
  a 
  strong 
  growth 
  of 
  green 
  algae. 
  These 
  were 
  allowed 
  to 
  thrive 
  undis- 
  

   turbed 
  for 
  another 
  month, 
  when 
  more 
  ova 
  of 
  A. 
  vagus 
  were 
  transferred 
  to 
  it. 
  These 
  

   now 
  hatched 
  and 
  the 
  larvae 
  attained 
  about 
  half 
  size, 
  then 
  succumbing. 
  A 
  sufficiency 
  

   of 
  nutritive 
  matter 
  for 
  the 
  development 
  of 
  algae 
  may 
  perhaps 
  explain 
  the 
  very 
  occa- 
  

   sional 
  presence 
  of 
  Anopheline 
  larvae 
  in 
  artificial 
  breeding-places. 
  In 
  another 
  similar 
  

   experiment 
  about 
  80 
  ova 
  of 
  A 
  . 
  vagus 
  were 
  placed 
  on 
  the 
  medium. 
  All 
  failed 
  to 
  hatch, 
  

   though 
  10 
  ova, 
  as 
  a 
  control 
  on 
  tap 
  water, 
  duly 
  afforded 
  larvae. 
  A 
  succession 
  of 
  larvae 
  

   of 
  Sicgomvia 
  albopicta, 
  hatching 
  from 
  eggs 
  deposited 
  by 
  stray 
  females 
  on 
  the 
  material, 
  

   which 
  was 
  in 
  an 
  open 
  glass 
  jar 
  exposed 
  in 
  a 
  well-lighted 
  situation, 
  bred 
  up, 
  though 
  

   during 
  such 
  time 
  as 
  the 
  medium 
  remained 
  acid 
  and 
  foul, 
  newly 
  hatched 
  larvae 
  of 
  

   A. 
  vagus 
  transferred 
  to 
  it 
  soon 
  perished. 
  

  

  By 
  way 
  of 
  further 
  experiment 
  20 
  ova 
  of 
  A. 
  vagus 
  and 
  an 
  equal 
  number 
  of 
  

   those 
  of 
  S. 
  albopicta, 
  all 
  newly 
  laid, 
  were 
  placed 
  on 
  the 
  surface 
  of 
  a 
  thin 
  mucilage 
  of 
  

   rice 
  boiled 
  up 
  two 
  days 
  previous! 
  v. 
  Most 
  of 
  the 
  eggs 
  of 
  the 
  Stegomyia 
  hatched, 
  but 
  

   the 
  majority 
  of 
  the 
  larvae 
  died, 
  though 
  one 
  managed 
  to 
  survive 
  until 
  the 
  tenth 
  day. 
  

   Not 
  a 
  single 
  larva 
  of 
  A. 
  vagus 
  hatched, 
  although 
  control 
  ova 
  duly 
  afforded 
  larvae. 
  

  

  The 
  ova, 
  then, 
  would 
  hatch 
  on 
  all 
  normal 
  media. 
  The 
  growth 
  and 
  development 
  of 
  

   larvae 
  in 
  water 
  from 
  breeding-places 
  other 
  than 
  those 
  in 
  which 
  the 
  species 
  experi- 
  

   mented 
  with 
  is 
  usually 
  found 
  was 
  also 
  made 
  the 
  subject 
  of 
  enquiry. 
  The 
  results 
  again 
  

   were 
  not 
  in 
  accordance 
  with 
  expectation 
  : 
  the 
  larvae 
  of 
  the 
  various 
  open-country 
  

   species 
  could 
  be 
  bred 
  in 
  the 
  laboratory 
  to 
  maturity 
  in 
  natural 
  media 
  in 
  which 
  numerous 
  

   examinations 
  had 
  shown 
  constantly 
  the 
  entire 
  absence 
  of 
  the 
  larvae 
  of 
  the 
  species 
  under 
  

   experiment. 
  For 
  instance, 
  almost 
  within 
  a 
  stone's 
  throw 
  of 
  the 
  swamp 
  referred 
  to 
  

   (Table 
  I) 
  in 
  which 
  the 
  larvae 
  of 
  A. 
  aconitus, 
  A. 
  hyrcanus, 
  A. 
  fuliginosus 
  and 
  A. 
  

   barbirostris 
  were 
  found 
  in 
  such 
  great 
  abundance, 
  there 
  was 
  a 
  large 
  pond 
  of 
  stagnant 
  

   water, 
  well 
  shaded 
  by 
  rubber 
  trees, 
  varying 
  in 
  size 
  according 
  to 
  season, 
  but 
  during 
  

   most 
  of 
  the 
  year, 
  about 
  ten 
  yards 
  wide 
  and 
  twenty 
  long, 
  with 
  a 
  depth 
  of 
  one 
  to 
  three 
  

   feet. 
  The 
  water, 
  surface 
  drainage, 
  partly 
  from 
  a 
  road 
  and 
  partly 
  from 
  a 
  plantation 
  

   in 
  which 
  there 
  was 
  a 
  small 
  Chinese 
  and 
  Malay 
  settlement, 
  was 
  always 
  turbid 
  and 
  

   sometimes 
  malodorous 
  both 
  from 
  vegetable 
  and 
  animal 
  pollution, 
  and 
  a 
  green 
  scum, 
  

   due 
  to 
  the 
  presence 
  in 
  almost 
  pure 
  culture 
  of 
  Protozoa 
  (determined 
  by 
  Dr. 
  Stanton 
  as 
  

   a 
  species 
  of 
  Euglena, 
  probably 
  viridis) 
  was 
  present 
  on 
  the 
  surface 
  during 
  the 
  period 
  

   the 
  investigation 
  was 
  carried 
  out. 
  The 
  only 
  Anopheline 
  larvae 
  ever 
  found 
  in 
  this 
  

   water, 
  in 
  spite 
  of 
  their 
  proximity 
  in 
  such 
  great 
  abundance 
  in 
  the 
  water 
  of 
  swamp 
  (A 
  ) 
  

   near 
  by, 
  were 
  those 
  of 
  A. 
  vagus, 
  and 
  these 
  but 
  sparingly. 
  In 
  view 
  of 
  the 
  scantines- 
  oi 
  

   these 
  particular 
  larvae, 
  suggesting 
  rather 
  unfavourable 
  environment 
  (since 
  they 
  

   abounded 
  in 
  road 
  pools 
  near 
  by) 
  and 
  of 
  the 
  entire 
  absence 
  of 
  other 
  species, 
  suggesting 
  

   complete 
  unsuitability 
  of 
  conditions 
  for 
  them, 
  any 
  success 
  in 
  breeding 
  the 
  open- 
  

   country 
  Anophelines 
  in 
  this 
  water 
  was 
  hardly 
  to 
  be 
  anticipated. 
  But 
  expectations 
  

   were 
  falsified 
  ; 
  the 
  water 
  proved 
  to 
  be 
  the 
  best 
  medium 
  of 
  many 
  tried 
  by 
  the 
  writer 
  

  

  