﻿ENTOMOLOGICAL 
  ASPECTS 
  OF 
  AN 
  OUTBREAK 
  OF 
  SLEEPING 
  SICKNESS. 
  319 
  

  

  All 
  these 
  opportunities 
  for 
  extended 
  entomological 
  investigation 
  were 
  particularly 
  

   welcome 
  at 
  a 
  time 
  when 
  this 
  fly 
  could 
  still 
  (for 
  a 
  few 
  weeks) 
  be 
  studied 
  in 
  its 
  normal 
  

   relation 
  to 
  the 
  infected 
  population, 
  and 
  especially 
  useful 
  in 
  the 
  case 
  of 
  a 
  tsetse, 
  which 
  

   I 
  was 
  convinced 
  was 
  undescribed 
  and 
  of 
  the 
  habits 
  of 
  which 
  — 
  so 
  all-important 
  in 
  

   relation 
  to 
  control 
  — 
  nothing 
  whatever 
  was 
  known. 
  The 
  assistance 
  was 
  well-timed 
  

   also 
  in 
  relation 
  to 
  the 
  need 
  for 
  an 
  immediate 
  knowledge 
  of 
  the 
  distribution 
  of 
  the 
  

   infection. 
  

  

  Native 
  assistance 
  was 
  freely 
  employed 
  on 
  this 
  investigation, 
  as 
  it 
  was 
  felt 
  that 
  

   much 
  might 
  be 
  at 
  stake 
  and 
  that 
  no 
  time 
  should 
  be 
  lost 
  in 
  ascertaining 
  the 
  distribution 
  

   of 
  the 
  infection 
  and 
  the 
  present 
  limits 
  of 
  the 
  tsetse. 
  Expeditions 
  composed 
  of 
  

   fly-boys 
  with 
  bait-cattle, 
  to 
  report 
  eventually 
  to 
  Dr. 
  Maclean 
  and 
  to 
  continue 
  to 
  be 
  

   employed 
  by 
  him 
  for 
  fly-work 
  for 
  as 
  long 
  as 
  might 
  seem 
  necessary, 
  were 
  sent 
  by 
  

   me 
  through 
  the 
  infested 
  woodland 
  to 
  the 
  Serengeti 
  Plain, 
  Lake 
  Eyasi, 
  the 
  Tungu 
  

   River, 
  Ukerewe 
  Island, 
  and 
  elsewhere. 
  Only 
  quite 
  local 
  expeditions 
  had 
  rejoined 
  

   us 
  before 
  I 
  left. 
  I 
  also, 
  throughout 
  the 
  investigation, 
  kept 
  native 
  shooters 
  employed 
  

   in 
  obtaining 
  material, 
  particularly 
  rock-rabbits 
  (Hyrax) 
  for 
  blood 
  examination 
  by 
  

   Dr. 
  Maclean 
  and 
  to 
  keep 
  me 
  well 
  in 
  touch 
  with 
  the 
  presence 
  or 
  absence 
  of 
  game. 
  

  

  I 
  am 
  indebted 
  for 
  information 
  bearing 
  on 
  this 
  investigation 
  and 
  other 
  direct 
  

   assistance 
  to 
  the 
  persons 
  already 
  mentioned, 
  to 
  Capt. 
  B. 
  D. 
  Armstrong 
  and 
  

   Capt. 
  R. 
  G. 
  H. 
  Wilson, 
  D.S.O., 
  M.G., 
  of 
  the 
  2nd 
  King's 
  African 
  Rifles 
  ; 
  to 
  the 
  Senior 
  

   Commissioner, 
  Tabora 
  (Mr. 
  H. 
  C. 
  Sticbel) 
  ; 
  to 
  the 
  Assistant 
  Political 
  Officer, 
  Chinyanga 
  

   (Mr. 
  G. 
  F. 
  Bell); 
  to 
  the 
  Rev. 
  A. 
  X. 
  Davis 
  ; 
  to 
  the 
  Senior 
  Commissioner, 
  Medical 
  Officer 
  

   and 
  Sanitation 
  Officer, 
  Kisumu 
  (Mr. 
  H. 
  R. 
  Tate 
  and 
  Drs. 
  G. 
  R. 
  H. 
  Chell 
  and 
  F. 
  J. 
  C. 
  

   Johnstone) 
  ; 
  and 
  to 
  the 
  Principal 
  Medical 
  Officer, 
  Principal 
  Sanitation 
  Officer 
  and 
  

   Government 
  Entomologist, 
  Nairobi 
  (Drs. 
  J. 
  L. 
  Gilks 
  and 
  A. 
  R. 
  Paterson 
  and 
  

   Mr. 
  T. 
  J. 
  Anderson). 
  

  

  It 
  will 
  be 
  seen 
  that 
  the 
  outbreak 
  offers 
  several 
  points 
  of 
  exceptional 
  interest. 
  

   The 
  fly 
  responsible 
  for 
  it 
  — 
  ■" 
  sali 
  " 
  of 
  the 
  local 
  natives 
  — 
  is 
  of 
  the 
  morsitans 
  group, 
  

   yet 
  the 
  disease 
  is 
  in 
  epidemic 
  form 
  and 
  six 
  and 
  a 
  half 
  degrees 
  farther 
  north 
  than 
  the 
  

   most 
  northerly 
  recorded 
  case 
  of 
  Trypanosoma 
  rhodesiense. 
  

  

  Whether 
  the 
  parasite 
  actually 
  is 
  T. 
  rhodesiense 
  or 
  whether 
  (as 
  a 
  little 
  of 
  the 
  

   evidence 
  suggested) 
  it 
  might 
  be 
  T. 
  gambiense, 
  was 
  being 
  studied 
  by 
  Dr. 
  Maclean 
  

   and 
  has, 
  since 
  I 
  left, 
  become 
  the 
  subject 
  of 
  a 
  special 
  investigation 
  by 
  Dr. 
  H. 
  L. 
  Duke, 
  

   who 
  was 
  lent 
  by 
  the 
  Uganda 
  Government 
  for 
  this 
  purpose. 
  It 
  is 
  to 
  be 
  hoped 
  that 
  

   definite 
  evidence 
  as 
  to 
  the 
  relations 
  of 
  the 
  trypanosomes 
  and 
  as 
  to 
  the 
  actual 
  

   importance 
  of 
  each 
  of 
  the 
  two 
  modes 
  of 
  transmission 
  may 
  emerge 
  from 
  his 
  results, 
  

   which 
  must 
  in 
  any 
  event 
  be 
  of 
  the 
  very 
  highest 
  interest. 
  

  

  Further 
  outstanding 
  points 
  were 
  the 
  dense 
  stand 
  of 
  very 
  young 
  woody 
  growth 
  

   that 
  is 
  threatening 
  to 
  convert 
  the 
  greater 
  part 
  of 
  the 
  belt 
  of 
  wooding 
  into 
  thicket 
  ; 
  

   the 
  effect 
  of 
  population 
  in 
  completely 
  clearing 
  great 
  areas 
  ; 
  the 
  evidence 
  therefrom 
  

   •of 
  the 
  number 
  of 
  settlers 
  required 
  to 
  keep 
  down 
  tsetse 
  automatically, 
  and 
  the 
  

   possibility 
  that 
  local 
  surpluses 
  of 
  men 
  and 
  cattle 
  might 
  by 
  organisation 
  and 
  inducement 
  

   be 
  diverted 
  to 
  the 
  suppression 
  of 
  tsetse 
  belts 
  ; 
  some 
  evidence 
  for 
  the 
  probable 
  

   effectiveness 
  of 
  merely 
  partial 
  clearing 
  ; 
  the 
  peculiarly 
  anthropophagous 
  habits 
  of 
  

   the 
  fly 
  ; 
  the 
  free 
  " 
  following 
  " 
  of 
  female 
  flies 
  across 
  open 
  barriers 
  ; 
  the 
  evidence 
  that 
  

   the 
  fly 
  ranges 
  out 
  to 
  conspicuous 
  trees, 
  etc., 
  in 
  the 
  open 
  ; 
  the 
  fact 
  that 
  it 
  differs 
  

   from 
  G. 
  morsitans, 
  its 
  nearest 
  described 
  ally, 
  in 
  certain 
  important 
  details 
  ; 
  the 
  position, 
  

   in 
  the 
  bush 
  villages, 
  as 
  regards 
  the 
  possibility 
  of 
  much 
  direct 
  transmission 
  of 
  the 
  

   trypanosome 
  ; 
  the 
  apparent 
  man-to-man 
  nature 
  of 
  the 
  infection, 
  travelling 
  chiefly, 
  

   it 
  appeared, 
  outwards 
  from 
  a 
  centre 
  ; 
  and, 
  most 
  important 
  of 
  all, 
  the 
  light 
  which 
  

   the 
  history 
  of 
  the 
  outbreak 
  appears 
  to 
  throw 
  on 
  what 
  would 
  be 
  the 
  effect 
  (1) 
  on 
  the 
  

   tsetse, 
  (2) 
  on 
  the 
  trypanosomiasis 
  of 
  man, 
  of 
  a 
  destruction 
  of 
  the 
  game. 
  I 
  believe 
  

   that 
  the 
  much-needed 
  experiment 
  in 
  game-destruction 
  has 
  here, 
  for 
  practical 
  

   purposes, 
  been 
  carried 
  out, 
  and 
  that 
  we 
  know 
  the 
  result. 
  

  

  (8053) 
  y 
  

  

  