﻿INVESTIGATIONS 
  INTO 
  THE 
  BIONOMICS 
  OF 
  GLOSSINA 
  PALPALIS. 
  349 
  

  

  some 
  new 
  and 
  some 
  old 
  and 
  discarded, 
  were 
  found 
  along 
  a 
  two-mile 
  reach 
  of 
  shore, 
  

   indicating 
  regular 
  and 
  long-continued 
  contact 
  between 
  trespassers 
  and 
  fly 
  at 
  its 
  

   very 
  worst. 
  Less 
  aggravated 
  conditions 
  were 
  frequently 
  encountered 
  along 
  many 
  

   reaches 
  of 
  mainland 
  shore. 
  

  

  On 
  returning 
  to 
  Entebbe 
  a 
  special 
  survey 
  was 
  made 
  for 
  fly 
  within 
  the 
  inhabited 
  

   precincts 
  and 
  for 
  trespassing 
  by 
  natives 
  beyond 
  them. 
  It 
  was 
  found 
  that 
  a 
  

   considerable 
  portion 
  of 
  the 
  township 
  was 
  very 
  lightly, 
  but 
  constantly 
  or 
  regularly, 
  

   infested 
  by 
  fly 
  (to 
  an 
  easily 
  measurable 
  degree), 
  and 
  that 
  at 
  certain 
  points 
  in 
  the 
  

   environs 
  natives 
  went 
  freely 
  into 
  contact 
  with 
  fly 
  at 
  a 
  moderate 
  — 
  but 
  nowhere 
  

   excessive 
  — 
  degree 
  of 
  density. 
  Similar 
  conditions 
  prevailed 
  at 
  Jinja 
  and 
  at 
  Kampala, 
  

   the 
  two 
  other 
  lake 
  ports. 
  

  

  With 
  these 
  conditions 
  in 
  mind, 
  inquiry 
  was 
  made 
  concerning 
  the 
  number 
  of 
  

   cases 
  of 
  sleeping 
  sickness 
  recorded 
  in 
  the 
  official 
  death 
  returns 
  or 
  coming 
  to 
  the 
  

   attention 
  of 
  Medical 
  Officers 
  ; 
  for 
  it 
  was 
  thought 
  certain 
  that 
  some 
  must 
  occur. 
  

   To 
  my 
  very 
  great 
  surprise 
  I 
  learned 
  that, 
  so 
  far 
  as 
  known, 
  not 
  a 
  single 
  case 
  had 
  

   been 
  contracted 
  within 
  the 
  Province 
  of 
  Buganda 
  — 
  for 
  which 
  the 
  returns 
  are 
  most 
  

   reliable 
  — 
  since 
  1912, 
  and 
  that 
  with 
  the 
  exception 
  of 
  two 
  cases 
  (one 
  of 
  them 
  not 
  surely 
  

   trypanosomiasis, 
  and 
  the 
  other 
  possibly 
  contracted 
  in 
  Busoga) 
  among 
  the 
  men 
  who 
  

   accompanied 
  Dr. 
  G. 
  D. 
  H. 
  Carpenter 
  on 
  his 
  tour 
  to 
  the 
  islands 
  in 
  1911-12, 
  no 
  cases 
  

   were 
  known 
  or 
  suspected 
  to 
  have 
  been 
  contracted 
  since 
  the 
  islands 
  were 
  depopulated 
  

   in 
  1909. 
  

  

  A 
  curious 
  situation 
  was 
  thus 
  created, 
  which 
  led 
  to 
  the 
  abandonment 
  of 
  the 
  

   proposed 
  experiment 
  and 
  to 
  complete 
  readjustment 
  of 
  ideas 
  and 
  preconceptions. 
  

   In 
  theory 
  — 
  the 
  theory 
  upon 
  which 
  the 
  suppressive 
  and 
  preventive 
  measures 
  had 
  

   been 
  based 
  — 
  complete 
  severance 
  of 
  contact 
  between 
  fly 
  and 
  population 
  was 
  necessary 
  

   in 
  order 
  to 
  control 
  sleeping 
  sickness, 
  but 
  in 
  actual 
  practice 
  complete 
  severance 
  

   of 
  contact 
  was 
  found 
  to 
  be 
  unnecessary. 
  In 
  theory 
  it 
  was 
  necessary 
  either 
  to 
  exter- 
  

   minate 
  fly 
  from 
  populated 
  districts 
  or 
  to 
  make 
  removal 
  of 
  inhabitants 
  " 
  from 
  the 
  

   vicinity 
  of 
  tsetse 
  complete 
  and 
  without 
  exception 
  " 
  ; 
  but 
  in 
  practice 
  it 
  was 
  proved 
  

   sufficient 
  to 
  reduce 
  the 
  density 
  of 
  fly 
  to 
  within 
  moderate 
  limits 
  in 
  populated 
  districts 
  

   or 
  to 
  reduce 
  density 
  of 
  population 
  to 
  within 
  moderate 
  limits 
  in 
  fly-infested 
  territory. 
  

  

  If 
  this 
  is 
  really 
  sufficient, 
  knowledge 
  concerning 
  factors 
  which 
  control 
  range 
  

   of 
  the 
  insect 
  is 
  more 
  or 
  less 
  superfluous, 
  whereas 
  knowledge 
  of 
  factors 
  which 
  operate 
  

   to 
  control 
  breadth 
  of 
  contact 
  between 
  fly 
  and 
  population 
  — 
  equivalent 
  to 
  frequency 
  

   of 
  contact 
  between 
  hungry 
  flies 
  and 
  men 
  — 
  is 
  specifically 
  required. 
  

  

  Two 
  very 
  different 
  lines 
  of 
  study 
  are 
  thus 
  outlined. 
  Which 
  of 
  them 
  ought 
  to 
  be 
  

   followed 
  ? 
  

  

  As 
  a 
  matter 
  of 
  fact, 
  both 
  were 
  followed 
  : 
  the 
  first 
  up 
  to 
  1915, 
  and 
  the 
  second 
  

   during 
  the 
  last 
  months 
  of 
  field 
  work. 
  One 
  of 
  them 
  was 
  impractical, 
  and 
  the 
  specific 
  

   results 
  of 
  it 
  are 
  practically 
  valueless, 
  except 
  as 
  disjointed 
  fragments 
  of 
  information 
  

   gained 
  can 
  be 
  salvaged 
  for 
  use 
  in 
  other 
  connexions. 
  Which 
  of 
  these 
  two 
  lines 
  

   of 
  investigation 
  ought 
  to 
  be 
  reported 
  upon 
  ? 
  

  

  In 
  the 
  accompanying 
  manuscript 
  neither 
  has 
  been 
  reported 
  upon, 
  because 
  this 
  

   question 
  has 
  not 
  been 
  answered, 
  nor 
  any 
  specific 
  object 
  for 
  the 
  preparation 
  of 
  any 
  

   (659) 
  

  

  