﻿130 
  W. 
  A. 
  LAMBORN. 
  

  

  Methods 
  of 
  Breeding. 
  

  

  At 
  the 
  commencement 
  of 
  the 
  work 
  there 
  was 
  considerable 
  difficulty 
  such 
  as 
  has 
  

   been 
  experienced 
  by 
  other 
  workers, 
  which 
  largely 
  explains 
  the 
  absence 
  of 
  precise 
  data 
  

   on 
  the 
  life-history 
  of 
  Anophelines. 
  The 
  insects 
  oviposited 
  in 
  any 
  water 
  provided, 
  

   but 
  though 
  all 
  sorts 
  of 
  water 
  were 
  tried 
  in 
  the 
  laboratory 
  for 
  rearing 
  the 
  larvae, 
  

   indifferent 
  success 
  was 
  met 
  with, 
  even 
  though 
  water 
  in 
  which 
  particular 
  larvae 
  

   occurred 
  in 
  abundance 
  in 
  nature 
  was 
  used 
  and 
  changed 
  daily. 
  Nor 
  were 
  better 
  

   results 
  obtained 
  when 
  the 
  bowls 
  containing 
  the 
  larvae 
  of 
  open 
  country 
  species 
  were 
  

   placed 
  in 
  situations 
  comparable 
  as 
  regards 
  sun, 
  wind 
  and 
  temperature 
  to 
  those 
  in 
  

   which 
  they 
  are 
  found 
  in 
  nature. 
  For 
  the 
  small-pool 
  breeders 
  a 
  hay 
  infusion, 
  in 
  which 
  

   a 
  fairly 
  luxuriant 
  culture 
  of 
  small 
  round 
  green 
  algae 
  from 
  such 
  breeding-places 
  had 
  

   been 
  obtained, 
  yielded 
  rather 
  better 
  results 
  than 
  were 
  previously 
  obtained 
  for 
  

   A. 
  vagus 
  and 
  A. 
  subpictus, 
  and 
  a 
  few 
  imagos 
  of 
  A. 
  maculatus 
  and 
  A. 
  karwari 
  were 
  

   obtained 
  from 
  the 
  egg, 
  the 
  larvae 
  feeding 
  up 
  on 
  a 
  species 
  of 
  Spirogyra. 
  For 
  certain 
  

   species 
  — 
  A 
  . 
  aconitus 
  and 
  A 
  . 
  maculatus 
  — 
  gently-running 
  water 
  containing 
  filamentous 
  

   algae, 
  such 
  as 
  are 
  not 
  readily 
  washed 
  away, 
  was 
  tried, 
  and, 
  at 
  Dr. 
  Hacker's 
  suggestion, 
  

   aeration 
  of 
  the 
  alga-containing 
  water 
  was 
  effected 
  by 
  means 
  of 
  a 
  siphon. 
  These 
  

   devices 
  were 
  all 
  to 
  little 
  purpose, 
  so 
  far 
  as 
  getting 
  families 
  of 
  Anophelines 
  sufficiently 
  

   numerous 
  for 
  generalisation 
  was 
  concerned. 
  

  

  Stagnant 
  and 
  polluted 
  water, 
  containing 
  a 
  rich 
  and 
  almost 
  pure 
  culture 
  of 
  a 
  

   Euglena 
  (determined 
  by 
  Dr. 
  Stanton 
  as 
  probably 
  E. 
  viridis) 
  was 
  then 
  tried, 
  and, 
  

   as 
  has 
  been 
  described 
  elsewhere,* 
  on 
  this 
  unpromising 
  medium 
  were 
  bred 
  from 
  egg 
  

   to 
  imago 
  considerable 
  families 
  of 
  all 
  the 
  open-country 
  Anophelines 
  : 
  A. 
  hyrcanus, 
  

   Pall., 
  A. 
  barbirostris, 
  Wulp, 
  A. 
  maculatus, 
  Theo., 
  A. 
  karwari, 
  James, 
  A. 
  vagus, 
  Don., 
  

   A. 
  subpictus 
  var. 
  malayensis, 
  Hacker, 
  A. 
  ludlowi, 
  Theo., 
  A. 
  aconitus, 
  Don., 
  A. 
  kochi, 
  

   Don., 
  A.fuliginosus, 
  Giles, 
  and 
  A. 
  tessellatus, 
  Theo. 
  No 
  success 
  at 
  all 
  was 
  met 
  with 
  in 
  

   regard 
  to 
  A 
  . 
  umbrosus, 
  and 
  ova 
  of 
  A 
  . 
  leucosphyrus 
  and 
  A 
  . 
  albotaeniatus 
  var. 
  montanus, 
  

   Stanton 
  & 
  Hacker, 
  were 
  not 
  obtained, 
  though 
  young 
  larvae 
  of 
  the 
  former 
  were 
  

   readily 
  bred 
  to 
  maturity 
  on 
  the 
  medium. 
  

  

  The 
  interpretation 
  of 
  the 
  success 
  met 
  with 
  in 
  the 
  use 
  of 
  this 
  medium 
  is 
  possibly 
  

   provided 
  by 
  the 
  following 
  paragraphs 
  (from 
  " 
  Comparative 
  Anatomy 
  of 
  Animals," 
  

   i, 
  1909, 
  by 
  Dr. 
  G. 
  C. 
  Bourne), 
  though 
  it 
  is 
  difficult 
  to 
  reconcile 
  the 
  apparent 
  welfare 
  

   of 
  the 
  " 
  clean 
  breeders 
  " 
  with 
  their 
  entire 
  absence 
  from 
  such 
  polluted 
  water 
  in 
  nature, 
  

   unless 
  it 
  is 
  that 
  the 
  oxygen 
  set 
  free 
  in 
  abundance 
  renders 
  the 
  products 
  of 
  decomposition 
  

   harmless 
  by 
  oxidation 
  immediately 
  they 
  are 
  liberated. 
  

  

  " 
  One 
  of 
  the 
  most 
  striking 
  characteristics 
  of 
  Euglena 
  is 
  its 
  green 
  colour. 
  . 
  . 
  . 
  

   The 
  green 
  tint 
  is 
  due 
  to 
  the 
  number 
  of 
  circular 
  or 
  oval 
  discs 
  known 
  as 
  chromatophors. 
  

   . 
  . 
  . 
  The 
  green 
  colour 
  of 
  the 
  chromatophors 
  is 
  due 
  to 
  chlorophyll. 
  . 
  . 
  . 
  

   Just 
  as 
  green 
  plants 
  are 
  able, 
  through 
  the 
  agency 
  of 
  their 
  chlorophyll 
  corpuscles, 
  to 
  

   decompose 
  the 
  carbonic 
  acid 
  in 
  the 
  air, 
  setting 
  free 
  oxygen 
  and 
  combining 
  the 
  carbon 
  

   with 
  water 
  to 
  form 
  starch, 
  so 
  Euglena 
  is 
  able 
  to 
  decompose 
  carbonic 
  acid. 
  . 
  . 
  . 
  

   When 
  Euglenae 
  are 
  kept 
  in 
  a 
  vessel 
  in 
  bright 
  sunlight 
  bubbles 
  are 
  abundantly 
  formed 
  

   in 
  the 
  water 
  in 
  which 
  they 
  are 
  contained, 
  and 
  these 
  bubbles, 
  if 
  collected, 
  can 
  be 
  

   shown 
  to 
  consist 
  of 
  oxygen." 
  (p. 
  190.) 
  

  

  " 
  It 
  has 
  been 
  observed 
  that 
  Euglena 
  will 
  live 
  and 
  apparently 
  flourish 
  in 
  complete 
  

   darkness 
  for 
  as 
  long 
  as 
  39 
  days." 
  

  

  The 
  Reproductive 
  Capacity 
  of 
  Anophelines. 
  

  

  The 
  question 
  is 
  one 
  of 
  no 
  little 
  importance 
  in 
  connection 
  with 
  antimosquito 
  

   measures. 
  The 
  ova 
  laid 
  by 
  captive 
  females 
  were 
  counted 
  under 
  a 
  low 
  magnification, 
  

   and 
  though 
  very 
  small 
  errors 
  in 
  enumeration 
  may 
  have 
  occurred 
  by 
  reason 
  of 
  the 
  

   difficulty 
  of 
  the 
  task, 
  the 
  data 
  afforded 
  as 
  to 
  each 
  species 
  are 
  certainly 
  correct 
  within 
  

   small 
  limits. 
  But 
  the 
  reproductive 
  capacity 
  of 
  the 
  insects, 
  ample 
  though 
  it 
  appears 
  

   by 
  the 
  data, 
  has 
  probably 
  been 
  far 
  underestimated, 
  partly 
  owing 
  to 
  the 
  uncertainty 
  

  

  * 
  Bull. 
  Ent. 
  Res., 
  xiii, 
  pt. 
  1, 
  p. 
  11, 
  May 
  1922. 
  

  

  