﻿370 
  PEOCEEDINGS 
  OF 
  THE 
  FOUHTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  temperature, 
  or 
  some 
  gustatory, 
  tactile, 
  or 
  visual 
  perception, 
  will 
  be 
  

   found 
  in 
  many 
  other 
  cases 
  to 
  supply 
  the 
  directive 
  influence 
  with 
  regard 
  

   to 
  particular 
  activities 
  : 
  their 
  investigation 
  will 
  similarly 
  lead 
  to 
  results 
  

   which 
  will 
  enlarge 
  our 
  powers. 
  

  

  The 
  investigation 
  of 
  these 
  " 
  susceptibilities 
  " 
  or" 
  tropic 
  responses," 
  

   and 
  the 
  practical 
  application 
  of 
  the 
  results 
  will 
  entail 
  in 
  some 
  cases 
  a 
  

   certain 
  amount 
  of 
  difficulty, 
  but 
  the 
  difficulty 
  is 
  more 
  on 
  the 
  chemical 
  

   than 
  on 
  the 
  entomological 
  side. 
  I 
  consider 
  it 
  to 
  be 
  extremely 
  probable, 
  

   for 
  instance, 
  that 
  many 
  agricultural 
  insect 
  pests 
  find 
  their 
  food 
  plants 
  

   entirely 
  or 
  almost 
  entirely 
  by 
  the 
  smell 
  of 
  the 
  whole 
  plant 
  or 
  of 
  some 
  

   particular 
  part 
  of 
  it 
  such 
  as 
  the 
  fruit. 
  It 
  will 
  often 
  be 
  necessary 
  to 
  

   appeal 
  to 
  the 
  chemist 
  or 
  the 
  plant-physiologist 
  for 
  information 
  as 
  to 
  

   the 
  substances 
  responsible 
  for 
  the 
  attraction 
  in 
  such 
  cases, 
  but 
  when 
  

   a 
  knowledge 
  of 
  these 
  substances 
  is 
  obtained 
  it 
  will 
  constitute 
  an 
  impor- 
  

   tant 
  addition 
  to 
  the 
  armoury 
  of 
  the 
  economic 
  entomologist. 
  One 
  or 
  

   two 
  of 
  the 
  more 
  obvious 
  ways 
  in 
  which 
  it 
  might 
  be 
  possible 
  to 
  utilize 
  

   it 
  occur 
  at 
  once 
  to 
  one's 
  mind 
  ; 
  it 
  might 
  be 
  practicable 
  to 
  use 
  the 
  directing 
  

   odoriferous 
  substance 
  as 
  a 
  trap 
  for 
  the 
  insect, 
  to 
  enhance 
  the 
  attrac- 
  

   tiveness 
  of 
  a 
  trap-crop, 
  to 
  neutralize 
  the 
  smell 
  or 
  taste 
  of 
  the 
  plant 
  by 
  

   special 
  traps 
  or 
  doctored 
  manures 
  or 
  to 
  " 
  breed 
  in 
  " 
  a 
  difierent 
  odour. 
  

   It 
  is 
  allowable 
  to 
  suppose 
  that 
  in 
  many 
  plants 
  the 
  chemical 
  characters 
  

   on 
  which 
  their 
  smell 
  and 
  taste 
  depend 
  may 
  be 
  susceptible 
  to 
  Mendelian 
  

   manipulation 
  in 
  the 
  same 
  way 
  as 
  are 
  those 
  which 
  determine 
  certain 
  

   other 
  qualities. 
  

  

  It 
  will 
  perhaps 
  be 
  remarked 
  : 
  — 
  " 
  This 
  talk 
  of 
  investigation 
  and 
  so 
  

   on 
  is 
  all 
  very 
  well, 
  but 
  surely 
  there 
  is 
  nothing 
  new 
  in 
  discovering 
  that 
  

   insects 
  are 
  guided 
  by 
  their 
  senses 
  : 
  what 
  else 
  should 
  they 
  be 
  guided 
  

   by 
  ? 
  " 
  The 
  point 
  on 
  which 
  depend 
  such 
  valuable 
  possibilities 
  is 
  not 
  

   that 
  they 
  are 
  guided 
  by 
  their 
  senses 
  in 
  a 
  general 
  way, 
  as 
  we 
  ourselves 
  

   are, 
  but 
  that 
  their 
  more 
  important 
  activities, 
  such 
  as 
  egg-laying 
  and 
  

   feedinof, 
  may 
  be 
  so 
  largely 
  influenced 
  by 
  one 
  or 
  two 
  particular 
  sensations 
  

   or 
  stimuli 
  that 
  they 
  may 
  be 
  practically 
  regarded 
  as 
  mechanical 
  responses 
  

   thereto. 
  By 
  pouring 
  mint-sauce 
  over 
  a 
  pair 
  of 
  boots 
  we 
  should 
  not 
  

   delude 
  any 
  ordinary 
  man 
  into 
  actually 
  eating 
  the 
  boots 
  under 
  the" 
  

   impression 
  that 
  he 
  was 
  being 
  actually 
  offered 
  roast 
  lamb, 
  but 
  we 
  can 
  

   so 
  delude 
  some 
  insects. 
  So 
  long 
  as 
  the 
  mint-sauce 
  is 
  there 
  the 
  lamb 
  

   is 
  taken 
  for 
  granted. 
  

  

  A 
  person 
  in 
  the 
  hypnotic 
  condition 
  referred 
  to 
  in 
  the 
  simile 
  given 
  

   above 
  has 
  been 
  rendered 
  peculiarly 
  susceptible 
  to 
  suggestion, 
  and 
  his 
  

   actions 
  may 
  be 
  dominated 
  by 
  one 
  or 
  two 
  ideas 
  to 
  which 
  all 
  else 
  is 
  sub- 
  

   servient. 
  Particular 
  sights, 
  sounds, 
  smells 
  or 
  tastes 
  may 
  be 
  made 
  the 
  

   stimuli 
  which 
  shall 
  evoke 
  in 
  him 
  the 
  strongest 
  desire 
  to 
  perform 
  certain 
  

  

  