﻿448 
  W. 
  F. 
  FISKE. 
  

  

  for 
  the 
  deprivative 
  effect 
  of 
  the 
  activities 
  of 
  leopards. 
  They 
  are 
  certainly 
  a 
  more 
  

   efficacious 
  natural 
  enemy 
  of 
  the 
  tsetse 
  than 
  spiders, 
  or 
  than 
  any 
  other 
  destructive 
  

   enemy 
  that 
  has 
  been 
  identified. 
  

  

  IX 
  (g). 
  Relations 
  between 
  Glossina 
  palpalis 
  and 
  other 
  Biting 
  Flies. 
  

  

  The 
  data 
  secured 
  during 
  the 
  experiments 
  with 
  cattle 
  described 
  in 
  Sect. 
  VI 
  (c) 
  (Table 
  

   XXV) 
  indicated 
  that 
  the 
  presence 
  of 
  other 
  biting 
  flies 
  than 
  Glossina 
  might 
  have 
  an 
  

   effect 
  on 
  host 
  animals 
  that 
  would 
  effectually 
  prevent 
  Glossina 
  from 
  feeding 
  upon 
  

   them. 
  This 
  has 
  since 
  been 
  confirmed 
  in 
  various 
  ways 
  ; 
  partly 
  by 
  a 
  series 
  of 
  

   observations 
  on 
  the 
  behaviour 
  of 
  domestic 
  animals, 
  or 
  of 
  animals 
  in 
  Zoological 
  

   Gardens, 
  under 
  attack 
  by 
  flies 
  of 
  various 
  species. 
  The 
  Zoological 
  Park 
  at 
  Washington 
  

   affords 
  particularly 
  good 
  opportunities 
  for 
  such 
  observations, 
  being 
  situated 
  well 
  

   out 
  from 
  the 
  city 
  in 
  a 
  naturally 
  wooded 
  ravine 
  where 
  Stomoxys 
  and 
  Tabanus 
  are 
  

   numerous. 
  Not 
  less 
  than 
  25 
  species 
  of 
  ungulates 
  occupy 
  paddocks 
  that 
  are 
  badly 
  

   infested 
  by 
  these 
  flies, 
  and 
  various 
  others, 
  including 
  several 
  of 
  the 
  familiar 
  game 
  

   animals 
  of 
  Africa, 
  have 
  runways 
  that 
  are 
  partly 
  exposed. 
  

  

  Variations 
  in 
  degree 
  of 
  tolerance 
  or 
  intolerance 
  to 
  attack 
  were 
  very 
  remarkable, 
  

   ranging 
  from 
  the 
  absolute 
  intolerance 
  of 
  Barbary 
  sheep, 
  which 
  would 
  seek 
  the 
  seclusion 
  

   of 
  their 
  hut 
  at 
  the 
  approach 
  of 
  a 
  single 
  Stomoxys, 
  to 
  the 
  phlegmatic 
  indifference 
  of 
  

   red 
  deer, 
  and 
  wapiti, 
  which 
  would 
  permit 
  Tabanus 
  to 
  engorge 
  without 
  serious 
  protest. 
  

   But 
  there 
  was 
  no 
  animal 
  that 
  was 
  not 
  roused 
  to 
  protest 
  and 
  retaliation 
  if 
  flies 
  became 
  

   too 
  numerous 
  and 
  persistent, 
  and 
  any 
  animal 
  that 
  is 
  thoroughly 
  aroused 
  and 
  excited 
  

   becomes 
  of 
  little 
  value 
  as 
  a 
  host 
  to 
  any 
  biting 
  fly. 
  

  

  Eland, 
  for 
  example, 
  was 
  passive 
  under 
  attack 
  by 
  Stomoxys 
  in 
  moderate 
  numbers, 
  

   but 
  repeatedly 
  on 
  approach 
  of 
  Tabanus 
  the 
  animals 
  would 
  betray 
  annoyance, 
  and 
  

   move 
  to 
  protect 
  themselves 
  not 
  only 
  against 
  the 
  greater 
  but 
  the 
  lesser 
  pest. 
  A 
  single 
  

   Tabanus 
  would 
  cause 
  all 
  the 
  elands 
  to 
  seek 
  shelter, 
  and 
  effectually 
  deprive 
  several 
  

   dozen 
  Stomoxys 
  of 
  this 
  particular 
  source 
  of 
  food. 
  Bison 
  was 
  more 
  tolerant 
  than 
  

   eland, 
  but 
  a 
  few 
  Tabanus 
  would 
  sometimes 
  set 
  a 
  whole 
  herd 
  in 
  motion. 
  Zebra 
  

   and 
  wild 
  horse 
  were 
  less 
  tolerant 
  than 
  eland, 
  but 
  would 
  suffer 
  Stomoxys 
  to 
  feed 
  in 
  

   small 
  numbers 
  until 
  Tabanus 
  appeared. 
  

  

  None 
  of 
  the 
  larger 
  biting 
  flies 
  observed 
  on 
  these 
  or 
  any 
  other 
  occasions 
  have 
  

   pressed 
  their 
  attack 
  on 
  an 
  unwilling 
  host 
  regardless 
  of 
  risk 
  to 
  themselves, 
  but 
  none 
  

   has 
  shown 
  more 
  regard 
  for 
  its 
  own 
  safety 
  or 
  been 
  quicker 
  to 
  desist 
  from 
  attack 
  upon 
  

   an 
  intolerant 
  host 
  than 
  Glossina 
  palpalis. 
  A 
  Tabanus 
  has 
  been 
  observed 
  to 
  return 
  

   to 
  the 
  attack 
  more 
  than 
  30 
  times 
  before 
  admitting 
  defeat. 
  A 
  Glossina, 
  unless 
  

   positively 
  famishing, 
  doubtfully 
  returns 
  more 
  than 
  4 
  or 
  5 
  times 
  at 
  the 
  most 
  — 
  perhaps 
  

   not 
  more 
  than 
  once 
  or 
  twice. 
  With 
  man 
  they 
  usually 
  desist 
  after 
  the 
  very 
  first 
  

   repulse. 
  The 
  more 
  persistent 
  pest 
  may, 
  therefore 
  (as 
  shown 
  by 
  the 
  experiment 
  — 
  

   Table 
  XXV) 
  become 
  a 
  very 
  efficacious 
  deprivative 
  enemy 
  of 
  the 
  less 
  persistent 
  

   and 
  the 
  effect 
  is 
  felt 
  in 
  two 
  distinctly 
  different 
  ways 
  : 
  — 
  (a) 
  the 
  host 
  animal 
  may 
  

   be 
  induced 
  to 
  leave 
  a 
  locality 
  or 
  district 
  where 
  it 
  is 
  liable 
  to 
  be 
  annoyed, 
  or 
  (b) 
  the 
  

   less 
  persistent 
  and 
  more 
  easily 
  discouraged 
  flies 
  may 
  be 
  induced 
  to 
  leave 
  the 
  locality 
  

   where 
  a 
  more 
  persistent 
  and 
  annoying 
  species 
  is 
  active. 
  

  

  