﻿10 
  DR. 
  H. 
  LYNDHURST 
  DUKE. 
  

  

  radius 
  than 
  to 
  a 
  similar 
  prevalence 
  throughout 
  the 
  belt. 
  Hamilton 
  notices 
  that 
  

   the 
  fly 
  were 
  concentrated 
  along 
  the 
  main 
  track 
  in 
  the 
  neighbourhood 
  of 
  camps 
  

   and 
  halting 
  places, 
  localities 
  in 
  which 
  experience 
  had 
  taught 
  the 
  insects 
  to 
  expect 
  

   their 
  supply 
  of 
  blood. 
  They 
  are 
  even 
  reduced 
  to 
  so 
  far 
  departing 
  from 
  their 
  usual 
  

   habits 
  as 
  to 
  bite 
  at 
  night 
  time. 
  Fiske, 
  among 
  other 
  reliable 
  observers, 
  has 
  drawn 
  

   attention 
  to 
  the 
  following 
  propensities 
  of 
  G. 
  morsitans. 
  " 
  In 
  the 
  Masindi 
  fly 
  belt, 
  

   the 
  only 
  morsitans 
  area 
  in 
  which 
  I 
  have 
  seriously 
  studied 
  this 
  fly, 
  I 
  have 
  noticed 
  

   that 
  the 
  passage 
  of 
  a 
  ' 
  safari 
  ' 
  of 
  porters 
  or, 
  better 
  still, 
  of 
  a 
  cyclist, 
  will 
  to 
  a 
  very 
  

   large 
  extent 
  clear 
  a 
  road 
  of 
  its 
  waiting 
  tsetse, 
  with 
  the 
  result 
  that 
  an 
  observer 
  

   following 
  on 
  a 
  short 
  time 
  afterwards 
  may 
  find 
  few 
  or 
  no 
  fly 
  until 
  arriving 
  near 
  the 
  

   edge 
  of 
  the 
  belt. 
  The 
  swarm 
  of 
  morsitans 
  which 
  sweeps 
  along 
  in 
  the 
  wake 
  and 
  round 
  

   the 
  person 
  of 
  a 
  cyclist 
  passing 
  through 
  a 
  fly 
  belt 
  gives 
  him 
  an 
  entirely 
  false 
  impression 
  

   as 
  to 
  the 
  true 
  prevalence 
  of 
  the 
  fly." 
  I 
  labour 
  this 
  point 
  because 
  the 
  fallacy 
  of 
  in- 
  

   ferring 
  from 
  the 
  numbers 
  of 
  tsetse 
  buzzing 
  about 
  the 
  observer 
  a 
  similar 
  infestation 
  

   of 
  the 
  belt 
  as 
  a 
  whole 
  is 
  by 
  no 
  means 
  rare. 
  

  

  A 
  consideration 
  of 
  all 
  these 
  points 
  reveals 
  an 
  alternative 
  or, 
  at 
  any 
  rate, 
  a 
  modified 
  

   explanation 
  of 
  the 
  facts 
  noted. 
  Game 
  was 
  very 
  rare 
  in 
  the 
  part 
  of 
  the 
  belt 
  traversed, 
  

   and 
  the 
  local 
  fly 
  were 
  probably 
  hard-pressed 
  for 
  mammalian 
  blood. 
  Hence 
  their 
  

   voracity 
  and 
  persistence, 
  and 
  their 
  concentration 
  at 
  spots 
  where, 
  in 
  addition 
  to 
  

   their 
  natural 
  liking 
  for 
  the 
  edge 
  of 
  a 
  path, 
  they 
  could 
  best 
  satisfy 
  their 
  hunger. 
  

   Further, 
  it 
  being 
  the 
  dry 
  season, 
  these 
  fly 
  would 
  tend 
  to 
  concentrate 
  in 
  certain 
  

   favoured 
  localities 
  (cf. 
  infra). 
  Probably 
  game 
  such 
  as 
  duiker, 
  oribi 
  and 
  warthog 
  

   existed 
  scattered 
  throughout 
  the 
  belt 
  ; 
  also 
  a 
  few 
  large 
  game 
  remained. 
  The 
  exis- 
  

   tence 
  of 
  fly 
  in 
  the 
  country 
  immediately 
  to 
  the 
  north 
  of 
  this 
  belt 
  in 
  1910 
  may 
  mean 
  

   that, 
  in 
  consequence 
  of 
  a 
  migration 
  of 
  the 
  game, 
  the 
  tsetse 
  were 
  gradually 
  shifting 
  

   northward 
  to 
  merge 
  with 
  the 
  Rovuma 
  belt, 
  in 
  a 
  richer 
  game 
  country. 
  

  

  Hamilton 
  himself 
  realises 
  the 
  danger 
  of 
  dogmatism 
  on 
  so 
  important 
  a 
  question 
  

   as 
  the 
  result 
  of 
  a 
  single 
  trip 
  ; 
  but 
  none 
  the 
  less, 
  he 
  has 
  laid 
  considerable 
  stress 
  on 
  the 
  

   apparent 
  independence 
  of 
  these 
  fly. 
  His 
  facts 
  show 
  that, 
  in 
  certain 
  localities, 
  

   morsitans 
  can 
  temporarily 
  adapt 
  itself 
  to 
  the 
  almost 
  total 
  absence 
  of 
  ungulate 
  game. 
  

   Natives 
  and 
  their 
  domestic 
  animals, 
  monkeys, 
  birds, 
  reptiles, 
  and 
  probably 
  hyaenas, 
  

   were 
  available 
  to 
  the 
  fly 
  in 
  the 
  present 
  instance. 
  Whether 
  the 
  survival 
  under 
  

   these 
  gameless 
  conditions 
  is 
  permanent, 
  or 
  merely 
  pending 
  an 
  alteration 
  of 
  range, 
  

   is 
  at 
  present 
  an 
  unsolved 
  question. 
  

  

  In 
  the 
  majority 
  of 
  the 
  tsetse 
  areas 
  of 
  British 
  East 
  Africa 
  it 
  appears 
  from 
  the 
  

   writings 
  of 
  Jackson, 
  Neumann, 
  and 
  others 
  (7) 
  that 
  game 
  occurs 
  only 
  in 
  very 
  small 
  

   quantities. 
  Neumann 
  (8), 
  describing 
  the 
  country 
  south 
  of 
  the 
  Athi 
  River 
  above 
  its 
  

   junction 
  with 
  the 
  Tsavo, 
  writes 
  : 
  ' 
  Here 
  are 
  great 
  stretches 
  of 
  uninhabited 
  bush 
  

   country 
  with 
  a 
  perennial 
  river 
  running 
  through 
  it, 
  and 
  hardly 
  any 
  animals, 
  though 
  

   plenty 
  of 
  birds 
  and 
  of 
  ' 
  fly,' 
  Tsetse." 
  But 
  in 
  his 
  description 
  of 
  this 
  scanty 
  

   game 
  he 
  says 
  " 
  a 
  very 
  few 
  waterbuck 
  at 
  intervals, 
  an 
  occasional 
  lesser 
  kudu 
  or 
  two, 
  

   a 
  little 
  lot 
  of 
  impala, 
  sometimes 
  at 
  one 
  particular 
  point, 
  and 
  rarely 
  an 
  odd 
  bushbuck, 
  

   are 
  all 
  that 
  are 
  seen, 
  without 
  counting 
  the 
  diminutive 
  paa, 
  and 
  now 
  and 
  again 
  a 
  

   rhino, 
  giraffe 
  or 
  hippo 
  spoor." 
  

  

  Here 
  we 
  have 
  a 
  fairly 
  comprehensive 
  menu, 
  however 
  barren 
  the 
  district 
  may 
  seem 
  

   to 
  the 
  hungry 
  hunter 
  ; 
  yet 
  it 
  is 
  just 
  'sufficiently 
  restricted 
  to 
  render 
  the 
  fly 
  

  

  