﻿PROCEEDINGS 
  OF 
  THE 
  FOUETII 
  ENTOMOLOGICAL 
  MEETING 
  193 
  

  

  two 
  cool 
  vessels 
  were 
  1°-3°C 
  below 
  and 
  the 
  two 
  warm 
  ones 
  5°-7^C 
  above 
  

   the 
  temperature 
  of 
  the 
  two 
  controls. 
  The 
  temperature 
  of 
  the 
  controls 
  

   was 
  practically 
  identical 
  with 
  the 
  air-temperature 
  ; 
  there 
  was 
  no 
  marked 
  

   fall 
  at 
  night, 
  owing 
  to 
  the 
  apparatus 
  being 
  in 
  a 
  closed 
  room. 
  The 
  tem- 
  

   perature 
  on 
  the 
  roof 
  of 
  the 
  cage 
  was 
  the 
  same 
  in 
  all 
  parts 
  of 
  it. 
  

  

  To 
  test 
  the 
  effect 
  of 
  osmotic 
  pressure, 
  solutions 
  of 
  common 
  salt 
  and 
  

   sugar 
  were 
  exposed 
  side 
  by 
  side, 
  the 
  object 
  being 
  to 
  eliminate 
  results 
  

   due 
  to 
  the 
  taste 
  of 
  the 
  solutions. 
  It 
  is 
  not 
  certain 
  how 
  the 
  taste 
  appeals 
  

   to 
  the 
  mosquito, 
  but 
  there 
  is 
  no 
  doubt 
  that 
  they 
  have 
  at 
  least 
  no 
  objection 
  

   to 
  sugar 
  solutions 
  of 
  a 
  wide 
  range 
  of 
  concentration. 
  

  

  Solutions 
  of 
  Sodium 
  taurocholate 
  were 
  used 
  in 
  the 
  series 
  designed 
  

   to 
  test 
  the 
  effect 
  of 
  loosing 
  the 
  surface-tension, 
  but 
  here 
  again 
  there 
  may 
  

   be 
  complications 
  due 
  to 
  taste- 
  effects. 
  A 
  solution 
  of 
  Saponin 
  was 
  also 
  

   included 
  in 
  this 
  series 
  ; 
  as 
  is 
  well 
  known, 
  it 
  has 
  the 
  effect 
  of 
  greatly 
  

   increasing 
  the 
  viscosity 
  of 
  water, 
  even 
  when 
  present 
  only 
  in 
  minute 
  

   quantities. 
  

  

  In 
  the 
  series 
  designed 
  to 
  test 
  the 
  effect 
  of 
  sweet, 
  salt, 
  astringent, 
  and 
  

   alkaline 
  substances, 
  it 
  was 
  necessary 
  to 
  eliminate 
  the 
  effect 
  of 
  variation 
  

   in 
  osmotic 
  pressure 
  by 
  using 
  isotonic 
  solutions 
  (M-10). 
  

  

  Each 
  series 
  of 
  observations 
  has 
  been 
  considered 
  in 
  relation 
  to 
  only 
  

   one 
  physical 
  or 
  chemical 
  factor, 
  but, 
  as 
  has 
  already 
  been 
  stated, 
  one 
  or 
  

   more 
  additional 
  factors 
  might 
  have 
  operated 
  to 
  make 
  the 
  results 
  what 
  

   otherwise 
  might 
  have 
  been 
  very 
  different. 
  We 
  shall 
  consider 
  some 
  of 
  

   the 
  more 
  important 
  possibilities 
  of 
  this 
  kind 
  in 
  the 
  course 
  of 
  our 
  

   discussion 
  of 
  the 
  results. 
  

  

  It 
  should 
  also 
  be 
  noted 
  that 
  the 
  predilection 
  of 
  mosquitos 
  to 
  oviposit 
  

   in 
  particular 
  kinds 
  of 
  water 
  has 
  not 
  been 
  considered 
  in 
  relation 
  to 
  a 
  vary- 
  

   ing 
  atmospheric 
  temperature 
  and 
  moisture. 
  Nor 
  has 
  the 
  fact 
  of 
  unequal 
  

   illumination 
  of 
  the 
  vessels 
  (placed 
  for 
  the 
  reception 
  of 
  eggs) 
  been 
  taken 
  

   into 
  consideration 
  in 
  adjudging 
  the 
  moscjuitos' 
  liking 
  for 
  any 
  particular 
  

   substance 
  for 
  oviposition. 
  

  

  In 
  the 
  absence 
  of 
  further 
  experiments 
  it 
  would 
  be 
  hardly 
  profitable 
  

   to 
  touch 
  on 
  the 
  general 
  question 
  of 
  how 
  far 
  the 
  maternal 
  instinct 
  modifies 
  

   the 
  phenomenon 
  of 
  oviposition, 
  though 
  the 
  subject 
  would 
  probably 
  repay 
  

   study, 
  especially 
  in 
  the 
  case 
  of 
  mosquitos, 
  where 
  the 
  fact 
  that 
  they 
  

   always 
  oviposit 
  in 
  water 
  offers 
  unusual 
  facilities 
  for 
  altering 
  the 
  condition 
  

   of 
  oviposition, 
  and 
  thereby 
  studying 
  the 
  effects 
  of 
  various 
  substances 
  

   both 
  on 
  the 
  incubation 
  period 
  of 
  eggs 
  and 
  on 
  the 
  well-being 
  of 
  the 
  off- 
  

   spring. 
  A 
  series 
  of 
  concurrent 
  observations 
  was 
  started 
  in 
  this 
  direction, 
  

   but 
  the 
  data 
  so 
  far 
  obtained 
  are 
  exceedingly 
  scanty. 
  In 
  our 
  present 
  

   paper 
  we 
  shall 
  confine 
  ourselves 
  practically 
  only 
  to 
  a 
  consideration 
  of 
  

   the 
  mosquitos' 
  partiality 
  for 
  any 
  special 
  kind 
  of 
  water 
  for 
  oviposition, 
  

  

  