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  PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  which 
  was 
  larger, 
  the 
  larvee 
  were 
  introduced 
  into 
  the 
  flask 
  by 
  means 
  

   of 
  a 
  small 
  wire-gauze 
  basket, 
  suspended 
  by 
  a 
  cotton 
  thread. 
  The 
  level 
  

   to 
  which 
  this 
  basket 
  was 
  lowered 
  was 
  the 
  same 
  as 
  that 
  of 
  the 
  bulb 
  of 
  

   the 
  thermometer 
  and 
  the 
  temperature 
  recorded 
  by 
  the 
  thermometer 
  

   therefore 
  represented 
  the 
  temperature 
  to 
  which 
  larvae 
  were 
  subjected. 
  

  

  When 
  the 
  basket 
  with 
  the 
  larvae 
  was 
  introduced 
  into 
  the 
  flask, 
  the 
  

   temperature 
  dropped 
  a 
  little 
  but 
  remained 
  fairly 
  constant 
  after 
  that. 
  

   The 
  larvse 
  were 
  taken 
  out 
  after 
  remaining 
  in 
  a 
  known 
  temperature 
  for 
  

   a 
  definite 
  time 
  and 
  kept 
  at 
  room 
  temperature 
  for 
  at 
  least 
  24 
  hours 
  to 
  

   see 
  if 
  any 
  survived. 
  In 
  some 
  cases 
  the 
  larvse 
  as 
  a 
  result 
  of 
  imperfect 
  

   penetration 
  of 
  heat, 
  became 
  motionless, 
  but 
  revived 
  after 
  24 
  hours. 
  

   So 
  that 
  all 
  the 
  larvse 
  treated 
  one 
  day 
  were 
  examined 
  after 
  24 
  hours. 
  

   For 
  temperatures 
  above 
  90° 
  C. 
  a 
  sand-bath 
  was 
  used 
  and 
  for 
  tempera- 
  

   ture 
  below 
  60° 
  C. 
  an 
  incubator 
  was 
  employed. 
  

  

  Over 
  500 
  observations 
  were 
  recorded 
  ; 
  for 
  every 
  temperature 
  the 
  

   experiments 
  were 
  repeated 
  twice 
  or 
  three 
  times 
  and 
  oftener 
  for 
  the 
  

   critical 
  temperature. 
  For 
  each 
  experiment 
  10 
  larvse 
  were 
  taken. 
  The 
  

   results 
  of 
  our 
  investigations 
  are 
  given 
  in 
  Tables 
  I 
  and 
  II, 
  and 
  graphically 
  

   represented 
  in 
  the 
  form 
  of 
  a 
  curve. 
  (Plates 
  XLIT, 
  XLIII). 
  

  

  Table 
  II. 
  

  

  Table 
  showing 
  Lethal 
  Temperatures 
  for 
  the 
  Larvce 
  oj 
  T. 
  khapra, 
  in 
  Rela- 
  

   tion 
  to 
  the 
  time 
  of 
  Exposure. 
  

  

  