﻿ENTOMOLOGICAL 
  ASPECTS 
  OF 
  AN 
  OUTBREAK 
  OF 
  SLEEPING 
  SICKNESS. 
  363 
  

  

  confirmed 
  the 
  conclusion 
  at 
  which 
  I 
  arrived 
  in 
  Portuguese 
  East 
  Africa 
  — 
  that 
  special 
  

   study 
  and 
  special 
  measures 
  or 
  modifications 
  of 
  measures 
  are 
  needed 
  for 
  each 
  

   separate 
  locality.* 
  

  

  Effect 
  of 
  Clearing 
  on 
  Water. 
  — 
  In 
  reply 
  to 
  the 
  criticism 
  that 
  clearing 
  (by 
  whatever 
  

   method) 
  for 
  the 
  eradication 
  of 
  tsetse 
  will 
  dry 
  up 
  the 
  natural 
  water-supply, 
  the 
  facts 
  

   observed 
  in 
  the 
  Usukuma 
  area 
  may 
  here 
  be 
  cited. 
  

  

  It 
  was 
  most 
  interesting 
  to 
  note 
  that 
  in 
  the 
  great 
  areas 
  that 
  have 
  been 
  completely 
  

   cleared 
  by 
  native 
  settlement 
  there 
  is 
  nowhere 
  insuperable 
  difficulty 
  over 
  water, 
  

   and 
  people 
  are 
  able 
  to 
  live 
  anywhere. 
  Moreover, 
  the 
  poor 
  savannah 
  wooding 
  that 
  

   constituted 
  the 
  shelter 
  of 
  the 
  fly 
  appeared 
  to 
  have 
  little 
  or 
  no 
  influence 
  in 
  conserving 
  

   the 
  water. 
  The 
  streams 
  both 
  in 
  it 
  and 
  in 
  the 
  cleared 
  country 
  outside 
  of 
  it 
  dry 
  into 
  

   pools 
  in 
  August, 
  and 
  the 
  only 
  difference, 
  as 
  Sultan 
  Mwanilanga 
  said, 
  was 
  that 
  in 
  the 
  

   cleared 
  areas 
  water 
  was 
  more 
  abundant 
  because 
  there 
  were 
  more 
  people 
  and 
  they 
  

   dug 
  more 
  water-holes. 
  

  

  Naturally 
  the 
  clearing 
  of 
  primary 
  forest, 
  in 
  districts 
  in 
  which 
  this 
  still 
  exists, 
  

   would 
  have 
  a 
  very 
  different 
  effect. 
  

  

  Precise 
  Measures. 
  

  

  The 
  measures 
  I 
  have 
  described 
  above 
  are 
  widely 
  applicable 
  measures 
  amounting, 
  

   in 
  effect, 
  to 
  a 
  general 
  policy 
  in 
  relation 
  to 
  the 
  tsetse 
  of 
  the 
  territory. 
  If 
  we 
  can 
  make 
  

   them 
  successful 
  — 
  and, 
  given 
  the 
  human 
  material 
  and 
  the 
  cattle, 
  this 
  should 
  be 
  merely 
  

   a 
  matter 
  of 
  organisation 
  and 
  watchfulness 
  — 
  they 
  will 
  both 
  prevent 
  the 
  serious 
  invasion 
  

   of 
  cattle 
  areas 
  by 
  tsetse 
  and 
  enable 
  us 
  to 
  take 
  over 
  from 
  the 
  fly 
  all 
  the 
  ground 
  we 
  

   more 
  urgently 
  require 
  for 
  the 
  accommodation 
  of 
  the 
  increase 
  of 
  the 
  cattle 
  of 
  the 
  

   territory, 
  as 
  such 
  increase 
  takes 
  place. 
  Under 
  such 
  a 
  policy 
  the 
  fact 
  that 
  tsetses 
  

   carry 
  trypanosomes 
  acquired 
  from 
  the 
  game 
  will 
  be 
  a 
  matter 
  of 
  supreme 
  indifference 
  

   to 
  us, 
  for 
  we 
  shall 
  have 
  all 
  the 
  tsetse-free 
  land 
  we 
  can 
  use, 
  and 
  the 
  rest 
  is 
  a 
  matter 
  

   of 
  careful 
  herding. 
  

  

  But 
  situations 
  may 
  still 
  arise 
  that 
  will 
  demand 
  a 
  rather 
  more 
  rapid 
  elimination 
  

   of 
  the 
  tsetses 
  in 
  a 
  particular 
  area 
  than 
  can 
  be 
  accomplished 
  by 
  means 
  of 
  our 
  gradual 
  

   invasion 
  of 
  the 
  fly-belts. 
  It 
  would 
  certainly 
  be 
  well 
  if 
  we 
  could 
  to-day 
  eliminate 
  

   the 
  Chinyanga 
  fly-belt 
  and 
  at 
  least 
  the 
  eastern 
  side 
  of 
  the 
  Usukuma 
  belt, 
  and 
  it 
  is 
  

   for 
  a 
  problem 
  of 
  this 
  kind 
  that 
  what 
  I 
  have 
  called 
  " 
  precise 
  " 
  measures 
  may 
  be 
  useful. 
  

   Such 
  measures 
  entail 
  an 
  exhaustive 
  preliminary 
  study 
  of 
  the 
  locality. 
  Primary 
  

   centres 
  of 
  the 
  fly, 
  breeding-places, 
  water-holes, 
  streams 
  and 
  swamps 
  must 
  be 
  located 
  ; 
  

   areas 
  of 
  bush 
  particularly 
  affording 
  egress 
  from 
  the 
  centres 
  to 
  the 
  main 
  woodland 
  

   sections 
  served 
  by 
  them 
  may 
  usefully 
  be 
  searched 
  for, 
  as 
  Shircore 
  long 
  ago 
  suggested 
  ; 
  

   lines 
  of 
  open 
  mbuga 
  that 
  might 
  be 
  connected 
  with 
  advantage 
  by 
  clearing 
  in 
  order 
  

   to 
  split 
  up 
  the 
  fly 
  area 
  should 
  be 
  noted, 
  and 
  other 
  points 
  of 
  attack 
  observed. 
  Finally, 
  

   on 
  the 
  data 
  collected, 
  the 
  real 
  campaign 
  can 
  be 
  planned. 
  The 
  most 
  important 
  line 
  

   of 
  attack 
  will 
  again 
  be 
  clearing 
  measures, 
  but 
  the 
  clearing 
  here 
  will 
  be 
  discriminative 
  

   — 
  directed 
  solely 
  against 
  the 
  strongholds 
  that 
  enable 
  the 
  fly 
  to 
  maintain 
  its 
  hold 
  on 
  

   the 
  country 
  generally. 
  These 
  in 
  some 
  belts 
  will 
  be 
  prohibitively 
  abundant, 
  in 
  others 
  

   fewer 
  and 
  more 
  easily 
  dealt 
  with. 
  

  

  * 
  Mr. 
  C. 
  W. 
  Hobley, 
  C.M.G., 
  who 
  has 
  had 
  exceptional 
  experience 
  of 
  native 
  administration 
  

   and 
  was 
  also 
  in 
  charge 
  of 
  the 
  Nyanza 
  Province 
  during 
  the 
  great 
  epidemic 
  on 
  the 
  Lake, 
  has 
  very 
  

   kindly 
  read 
  the 
  proofs 
  of 
  this 
  portion 
  of 
  the 
  paper 
  with 
  a 
  view 
  to 
  criticism. 
  He 
  regards 
  the 
  scheme 
  

   as 
  being 
  on 
  sound 
  lines 
  and 
  suggests, 
  for 
  country 
  in 
  which 
  the 
  streams 
  dry 
  up, 
  the 
  inducement 
  

   that 
  would 
  be 
  offered 
  by 
  the 
  erection 
  of 
  a 
  few 
  dams 
  and, 
  beside 
  open 
  "mbugas" 
  in 
  which 
  the 
  

   people 
  would 
  be 
  settled 
  first, 
  the 
  sinking 
  of 
  wells. 
  Goats 
  would 
  be 
  fanned 
  first. 
  Cattle 
  would 
  

   follow 
  when 
  it 
  was 
  perfectly 
  safe 
  for 
  them 
  to 
  do 
  so 
  and 
  the 
  clearings 
  would 
  eventually 
  coalesce. 
  

  

  This 
  adds 
  useful 
  detail 
  to 
  the 
  idea 
  of 
  "large 
  locations" 
  as 
  centres 
  from 
  which 
  to 
  invade 
  the 
  

   surrounding 
  tsetse-country, 
  and 
  it 
  is 
  possible 
  that 
  the 
  settlement 
  of 
  little 
  more 
  than 
  the 
  mbugas 
  

   alone 
  would, 
  as 
  I 
  have 
  suggested 
  under 
  " 
  Precise 
  Measures," 
  at 
  once 
  banish 
  the 
  tsetse. 
  

  

  