﻿200 
  PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  and 
  to 
  the 
  possibility 
  of 
  their 
  breeding 
  in 
  naturally 
  saline 
  water. 
  The 
  

   results 
  obtained 
  with 
  varying 
  percentages 
  of 
  Sodium 
  chloride 
  are 
  shown 
  

   in 
  the 
  accompanying 
  graph. 
  (Plate 
  XXXVI). 
  

  

  About 
  4 
  dozen 
  glass 
  dishes 
  of 
  almost 
  the 
  same 
  capacity 
  were 
  selected 
  

   for 
  experiments. 
  In 
  these 
  dishes 
  measured 
  quantities 
  of 
  various 
  solu- 
  

   tions 
  of 
  different 
  strengths 
  were 
  kspt 
  and 
  the 
  original 
  strength 
  was 
  

   maintained 
  by 
  adding 
  the 
  necessary 
  amount 
  of 
  distilled 
  water 
  after 
  

   every 
  24 
  hours, 
  to 
  make 
  up 
  the 
  deficiency 
  caused 
  by 
  evaporation. 
  Pure 
  

   water 
  was 
  used 
  as 
  a 
  control. 
  

  

  The 
  eggs 
  employed 
  in 
  the 
  experiment 
  were 
  those 
  of 
  Culex 
  fatigans, 
  

   because 
  it 
  is 
  the 
  most 
  common 
  domestic 
  mosquito 
  and 
  also 
  for 
  the 
  reason 
  

   that 
  it 
  breeds 
  almost 
  freely 
  even 
  in 
  very 
  low 
  temperatures, 
  as 
  these 
  

   experiments 
  were 
  performed 
  in 
  the 
  winter 
  season. 
  In 
  the 
  course 
  of 
  the 
  

   experiment 
  a 
  stage 
  arrived, 
  when 
  it 
  appeared 
  that 
  the 
  larvse 
  in 
  various 
  

   solutions 
  in 
  which 
  they 
  had 
  hatched, 
  were 
  suffering 
  in 
  development 
  

   owing 
  to 
  lack 
  of 
  food. 
  0-001 
  per 
  cent. 
  Sanatogen 
  was 
  therefore 
  added 
  in 
  

   each 
  dish. 
  This 
  addition 
  of 
  Sanatogen 
  gave 
  a 
  sort 
  of 
  stimulus 
  to 
  all 
  the 
  

   larvae. 
  Still 
  owing 
  to 
  the 
  low 
  atmospheric 
  temperature 
  prevailing 
  at 
  

   the 
  time 
  (being 
  winter) 
  the 
  development 
  was 
  exceedingly 
  slow. 
  

  

  In 
  some 
  chemicals 
  the 
  eggs 
  did 
  not 
  hatch 
  at 
  all, 
  in 
  some 
  the 
  eggs 
  

   did 
  not 
  develop 
  but 
  split 
  up 
  ; 
  while 
  in 
  some 
  the 
  larvae 
  died 
  while 
  just 
  

   in 
  the 
  act 
  of 
  emergence 
  ; 
  in 
  some 
  the 
  larvae 
  half 
  emerged 
  and 
  died 
  before 
  

   complete 
  emergence 
  ; 
  in 
  some 
  the 
  larvae 
  met 
  instantaneous 
  death 
  

   immediately 
  after 
  emergence 
  ; 
  in 
  some 
  the 
  larvae 
  prospered 
  for 
  some 
  

   time 
  but 
  died 
  before 
  attaining 
  full 
  maturity 
  ; 
  and 
  in 
  the 
  rest 
  they 
  attained 
  

   maturity 
  and 
  mosquitos 
  emerged. 
  

  

  In 
  determining 
  the 
  susceptibility 
  of 
  the 
  eggs 
  and 
  larvae 
  to 
  various 
  

   chemicals 
  the 
  results 
  fall 
  under 
  6 
  heads 
  : 
  — 
  

  

  Series 
  A. 
  (Life 
  cycle 
  incomplete) 
  — 
  

  

  (1) 
  Eggs 
  did 
  not 
  hatch. 
  

  

  (2) 
  Larvae 
  partially 
  hatched 
  and 
  died. 
  

  

  (3) 
  Larvae 
  hatched 
  and 
  died 
  instantaneously. 
  

  

  (4) 
  Larvae 
  hatched 
  and 
  died 
  in 
  less 
  than 
  24 
  hours. 
  

  

  (5) 
  Larvae 
  hatched, 
  survived 
  from 
  1 
  to 
  25 
  days 
  without 
  attaining 
  

  

  maturity. 
  

  

  Series 
  B 
  : 
  — 
  

  

  (6) 
  Life 
  cycle 
  complete. 
  

  

  