﻿ENTOMOLOGICAL 
  ASPECTS 
  OF 
  AN 
  OUTBREAK 
  OF 
  SLEEPING 
  SICKNESS. 
  357 
  

  

  stationary 
  screen 
  composed 
  of 
  a 
  square 
  of 
  khaki 
  stretched 
  between 
  two 
  sticks 
  at 
  

   4-6 
  feet 
  from 
  the 
  ground 
  caught 
  six 
  in 
  the 
  same 
  time. 
  The 
  figures 
  are 
  too 
  small 
  

   to 
  be 
  a 
  guide, 
  but 
  I 
  had 
  found 
  earlier 
  by 
  watching 
  it 
  that 
  flies 
  were 
  attracted 
  to 
  this 
  

   stationary 
  screen 
  and, 
  only 
  because 
  it 
  is 
  so 
  much 
  simpler 
  and 
  cheaper 
  to 
  make, 
  

   this 
  may 
  be 
  the 
  best 
  to 
  use 
  where 
  many 
  screens 
  are 
  required. 
  The 
  use 
  of 
  screens 
  

   necessitates 
  a 
  thoroughly 
  reliable 
  native 
  in 
  charge, 
  and 
  one 
  who 
  is 
  not 
  interested 
  in 
  the 
  

   catching 
  of 
  birds, 
  to 
  renew 
  the 
  lime 
  frequently, 
  and 
  the 
  latter 
  substance 
  has 
  to 
  be 
  

   put 
  on 
  so 
  thickly 
  that, 
  even 
  were 
  it 
  good, 
  it 
  would 
  probably 
  be 
  uneconomical 
  as 
  

   compared 
  with 
  commercial 
  fly-gums. 
  The 
  use 
  of 
  the 
  latter 
  substances 
  is 
  indicated, 
  

   and 
  the 
  screens 
  may 
  prove 
  a 
  useful 
  reducer 
  of 
  tsetses 
  in 
  bush 
  villages 
  and 
  

   (as 
  Shircore 
  suggested) 
  on 
  main 
  paths 
  — 
  the 
  two 
  places 
  in 
  which 
  continuously 
  

   man-feeding 
  tsetses 
  would 
  most 
  abound. 
  

  

  The 
  probable 
  value 
  of 
  propaganda 
  was 
  also 
  fully 
  realised. 
  With 
  the 
  native 
  once 
  

   well 
  convinced 
  of 
  the 
  danger 
  of 
  being 
  bitten, 
  the 
  distribution 
  of 
  small 
  nets 
  amongst 
  

   the 
  villages 
  might 
  be 
  the 
  best 
  remedy 
  against 
  the 
  " 
  direct 
  transmitter." 
  

  

  6. 
  To 
  prevent 
  the 
  Game 
  generally 
  from 
  becoming 
  infected 
  with 
  the 
  Human 
  Trypanosome. 
  

  

  In 
  first 
  reporting 
  on 
  this 
  investigation 
  I 
  was 
  impressed 
  by 
  the 
  risk 
  that 
  the 
  

   trypanosome 
  might 
  retain 
  its 
  acquired 
  virulence 
  for 
  man 
  even 
  after 
  cyclical 
  passage 
  

   through 
  the 
  fly 
  and 
  transmission 
  to 
  the 
  game, 
  and 
  by 
  the 
  fact 
  that, 
  as 
  little 
  game 
  

   was 
  probably 
  infected 
  as 
  yet, 
  and 
  that 
  mostly 
  between 
  the 
  Duma 
  and 
  Simiyu, 
  we 
  

   might 
  utilise 
  the 
  impending 
  evacuation 
  to 
  place 
  the 
  natives 
  in 
  such 
  a 
  way 
  as 
  to 
  

   complete 
  by 
  a 
  broad 
  strip 
  of 
  settlement 
  the 
  Maswa-Luguru 
  arc 
  of 
  cleared 
  country, 
  

   round 
  by 
  Ngasamo 
  and 
  the 
  Kilalo 
  clearing 
  to 
  the 
  Lake 
  at 
  Nasa 
  or 
  Masalu's 
  ; 
  and, 
  

   in 
  the 
  opposite 
  direction, 
  either 
  (shorter) 
  to 
  the 
  open 
  country 
  of 
  Nung-hu 
  or 
  (longer) 
  

   along 
  the 
  road 
  that 
  it 
  was 
  proposed 
  to 
  clear 
  from 
  Luguru 
  to 
  Sengerema. 
  This 
  

   would 
  make 
  nearly 
  game-proof 
  the 
  barrier 
  of 
  settlement 
  that 
  already 
  stands 
  in 
  the 
  

   way 
  of 
  the 
  annual 
  southward 
  and 
  westward 
  migrations 
  and 
  (on 
  the 
  hypothesis 
  

   stated) 
  prevent 
  more 
  game 
  from 
  becoming 
  infected 
  and 
  from 
  carrying 
  the 
  infection 
  

   far 
  and 
  wide. 
  I 
  recommended 
  that 
  the 
  natives 
  should 
  be 
  so 
  settled, 
  if 
  possible, 
  

   and 
  there 
  can 
  be 
  no 
  doubt 
  that 
  this 
  will 
  be 
  a 
  useful 
  measure 
  either 
  to 
  meet 
  such 
  a 
  

   situation 
  as 
  I 
  have 
  just 
  suggested 
  or 
  as 
  a 
  part 
  of 
  the 
  policy, 
  of 
  which 
  I 
  shall 
  shortly 
  

   say 
  more, 
  of 
  breaking 
  up 
  the 
  fly-belt 
  so 
  as 
  to 
  allow 
  us 
  to 
  attack 
  it 
  in 
  detail, 
  isolate 
  

   future 
  outbreaks, 
  and 
  check 
  the 
  movements 
  of 
  the 
  fly. 
  It 
  could 
  also 
  serve 
  as 
  a 
  base 
  

   for 
  invasion 
  inwards 
  by 
  reinforced 
  native 
  settlement 
  should 
  that 
  be 
  our 
  eventual 
  

   measure, 
  and 
  anything 
  approaching 
  an 
  absolute 
  barrier 
  against 
  the 
  game 
  might 
  

   enable 
  interesting 
  periodical 
  investigations 
  of 
  the 
  trypanosomes 
  in 
  its 
  blood 
  to 
  be 
  

   carried 
  out. 
  

  

  If, 
  on 
  the 
  other 
  hand, 
  the 
  trypanosome 
  loses 
  its 
  virulence 
  for 
  man 
  on 
  passing 
  

   into 
  the 
  game, 
  the 
  measure 
  would 
  still 
  be 
  useful 
  in 
  the 
  other 
  connections 
  I 
  have 
  

   mentioned. 
  Yet, 
  on 
  this 
  same 
  view, 
  it 
  might 
  be 
  a 
  very 
  great 
  pity 
  to 
  place 
  any 
  

   obstacles 
  in 
  the 
  way 
  of 
  flooding 
  the 
  area 
  with 
  game. 
  

  

  XXII. 
  — 
  A 
  Campaign 
  against 
  the 
  Fly. 
  

  

  The 
  following 
  remarks 
  on 
  measures 
  refer 
  rather 
  to 
  the 
  Territory 
  at 
  large 
  than 
  

   to 
  the 
  Mwanza 
  district 
  only, 
  but 
  they 
  are 
  for 
  the 
  most 
  part 
  as 
  applicable 
  to 
  the 
  

   latter 
  as 
  to 
  the 
  former. 
  Measures 
  against 
  tsetses 
  fall 
  into 
  two 
  categories 
  — 
  wholesale 
  

   (or 
  catastrophic) 
  and 
  precise. 
  In 
  the 
  first 
  I 
  include 
  such 
  things 
  as 
  general 
  late 
  

   grass-burning, 
  wholesale 
  clearing 
  of 
  bush 
  and 
  game 
  destruction. 
  In 
  the 
  second, 
  

   I 
  include 
  highly 
  localised 
  measures 
  against, 
  for 
  example, 
  the 
  primary 
  centres 
  of 
  the 
  

   fly, 
  these 
  having 
  first 
  been 
  carefully 
  located. 
  

  

  Each 
  of 
  these 
  categories 
  is 
  sub-divisible 
  into 
  (a) 
  special 
  and 
  usually 
  expensive 
  

   measures 
  — 
  such 
  as 
  special 
  clearing, 
  the 
  breeding 
  and 
  release 
  of 
  parasites 
  (least 
  

   expensive), 
  the 
  provision 
  of 
  artificial 
  " 
  trap 
  " 
  breeding-places, 
  or 
  game 
  destruction 
  

  

  