﻿THE 
  RELATIONS 
  OF 
  GLOSSINA 
  MORSITANS 
  AND 
  GAME. 
  19 
  

  

  the 
  flies 
  become 
  more 
  persistent 
  in 
  their 
  desire 
  to 
  feed 
  upon 
  man. 
  This 
  change 
  in 
  

   their 
  behaviour 
  is 
  also 
  coincident 
  with 
  the 
  coming 
  to 
  maturity 
  of 
  the 
  grass, 
  which 
  

   in 
  early 
  May 
  would 
  not 
  suffice 
  to 
  hide 
  even 
  a 
  duiker, 
  but 
  by 
  the 
  middle 
  of 
  June 
  would 
  

   completely 
  conceal 
  bushbuck 
  and 
  pig 
  in 
  most 
  localities, 
  and 
  larger 
  animals 
  in 
  

   some." 
  

  

  Now 
  the 
  rinderpest 
  commenced 
  in 
  Chopi 
  a 
  few 
  miles 
  to 
  the 
  north 
  of 
  the 
  scene 
  of 
  

   Fiske's 
  and 
  my 
  work 
  in 
  1914. 
  The 
  disease 
  spread 
  rapidly 
  through 
  the 
  buffalo, 
  which, 
  

   as 
  usual, 
  migrated, 
  some 
  going 
  towards 
  the 
  Bugungu 
  escarpment, 
  some 
  making 
  

   south 
  for 
  the 
  River 
  Kafu 
  and 
  Buganda. 
  Right 
  through 
  the 
  long 
  -grass 
  season 
  the 
  

   game 
  was 
  dying 
  in 
  numbers 
  throughout 
  the 
  fly 
  area. 
  The 
  elephant, 
  which 
  descend 
  

   towards 
  the 
  River 
  Kafu 
  in 
  the 
  rains, 
  were 
  still 
  in 
  the 
  thick 
  elephant-grass 
  country 
  

   of 
  the 
  Chopi 
  reserve. 
  Bushbuck 
  and 
  warthog 
  were 
  dying 
  in 
  numbers. 
  The 
  food 
  

   supply 
  of 
  the 
  fly 
  was 
  thus 
  severely 
  reduced 
  just 
  at 
  the 
  time 
  when 
  food 
  is, 
  under 
  

   ordinary 
  conditions, 
  most 
  difficult 
  to 
  find. 
  The 
  drought, 
  beginning 
  in 
  November, 
  

   led 
  to 
  an 
  early 
  drying 
  of 
  the 
  grass 
  and 
  commencement 
  of 
  the 
  fires. 
  Similarly 
  the 
  

   intensity 
  and 
  prolongation 
  of 
  this 
  drought 
  led 
  to 
  an 
  unusually 
  complete 
  burning 
  of 
  

   the 
  bush. 
  The 
  fly 
  were 
  thus 
  doubly 
  handicapped. 
  Firstly, 
  their 
  food 
  supply 
  was 
  

   diminished 
  at 
  the 
  most 
  critical 
  season 
  of 
  the 
  year 
  ; 
  and 
  secondly, 
  the 
  adverse 
  

   conditions 
  of 
  deprivation 
  of 
  shelter 
  and 
  destruction 
  of 
  breeding 
  grounds 
  were 
  inten- 
  

   sified 
  by 
  the 
  prolonged 
  drought. 
  

  

  I 
  consider 
  that 
  these 
  phenomena 
  afford 
  a 
  reasonable 
  and 
  probable 
  explanation 
  

   of 
  the 
  remarkable 
  diminution 
  in 
  the 
  numbers 
  of 
  tsetse 
  in 
  the 
  Masindi 
  fly 
  belt. 
  The 
  

   Bugungu 
  country, 
  being 
  uninhabited, 
  is 
  less 
  subject 
  to 
  burning 
  in 
  the 
  dry 
  season, 
  

   as 
  these 
  fires 
  are 
  started 
  and 
  kept 
  up 
  by 
  natives. 
  

  

  It 
  remains 
  now 
  to 
  be 
  seen 
  whether 
  the 
  principles 
  elucidated 
  in 
  connection 
  with 
  

   the 
  Masindi 
  morsitans 
  belt 
  are 
  applicable 
  to 
  the 
  problem 
  of 
  the 
  North-East 
  Transvaal. 
  

  

  In 
  this 
  latter 
  district 
  the 
  rinderpest 
  arrived 
  about 
  June 
  in 
  1896, 
  and 
  the 
  game 
  were 
  

   still 
  dying 
  fast 
  in 
  October, 
  the 
  hot 
  season. 
  The 
  grass 
  reaches 
  its 
  full 
  growth 
  in 
  June 
  

   and 
  in 
  some 
  years 
  the 
  fires 
  may 
  not 
  commence 
  until 
  September. 
  I 
  can 
  find 
  no 
  data 
  

   regarding 
  the 
  particular 
  climatic 
  conditions 
  obtaining 
  in 
  1896-7 
  in 
  this 
  part 
  of 
  the 
  

   Transvaal. 
  It 
  is 
  therefore 
  impossible 
  to 
  say 
  whether 
  or 
  not 
  the 
  dry 
  season 
  that 
  

   year 
  was 
  unusually 
  prolonged. 
  

  

  One 
  of 
  the 
  two 
  factors 
  already 
  discussed 
  in 
  dealing 
  with 
  the 
  Masindi 
  fly 
  is, 
  however, 
  

   common 
  to 
  both 
  cases, 
  i.e., 
  the 
  arrival 
  of 
  the 
  disease 
  in 
  the 
  district 
  at 
  the 
  season 
  of 
  

   the 
  year 
  when 
  the 
  grass 
  is 
  up 
  and 
  game 
  most 
  difficult 
  to 
  find. 
  

  

  Regarding 
  the 
  complete 
  and 
  permanent 
  disappearance 
  of 
  the 
  tsetse 
  from 
  a 
  large 
  

   strip 
  of 
  country, 
  described 
  by 
  Hamilton 
  as 
  coincident 
  with 
  the 
  passage 
  of 
  the 
  rinder- 
  

   pest, 
  it 
  would 
  appear 
  from 
  his 
  paper 
  that 
  he 
  arrived 
  in 
  the 
  district 
  in 
  1902, 
  some 
  

   five, 
  years 
  after 
  the 
  epidemic. 
  From 
  the 
  date 
  of 
  his 
  arrival 
  he 
  is 
  satisfied 
  that 
  no 
  

   recurrence 
  of 
  the 
  tsetse 
  in 
  their 
  former 
  haunts 
  has 
  taken 
  place. 
  That 
  the 
  fly 
  

   disappeared 
  completely 
  in 
  the 
  season 
  I 
  think 
  improbable. 
  

  

  The 
  truth 
  probably 
  is 
  that, 
  in 
  consequence 
  of 
  the 
  combination 
  of 
  adverse 
  conditions 
  

   afforded 
  by 
  the 
  arrival 
  of 
  the 
  disease 
  in 
  the 
  cold 
  weather, 
  together 
  with 
  a 
  prolonged 
  

   dry 
  season 
  with 
  consequent 
  more 
  complete 
  burning 
  of 
  the 
  grass, 
  the 
  fly 
  were 
  very 
  

   markedly 
  reduced 
  between 
  June 
  1896 
  and 
  April 
  1897. 
  Small 
  isolated 
  foci 
  probably 
  

  

  (572) 
  b2 
  

  

  