﻿PROCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  225 
  

  

  states 
  that 
  he 
  used 
  " 
  horse 
  flies 
  " 
  which 
  were 
  only 
  available 
  during 
  

   the 
  3 
  or 
  4 
  hottest 
  months, 
  presumably 
  Tabanidse 
  are 
  meant], 
  and 
  as 
  a 
  

   result 
  of 
  his 
  work 
  he 
  concluded 
  that 
  a 
  full 
  meal 
  seldom 
  infects, 
  but 
  an 
  

   interrupted 
  feeding 
  does.* 
  He 
  found 
  also 
  that 
  material 
  containing 
  

   the 
  organism 
  when 
  infested 
  can 
  only 
  infect 
  through 
  accidental 
  lesions 
  

   of 
  the 
  mouth 
  and 
  nose. 
  Pease 
  (1906) 
  described 
  Tibarsa 
  Surra 
  in 
  the 
  

   camel 
  and 
  stated 
  that 
  in 
  1903 
  eight 
  camel 
  corps 
  lost 
  1792 
  animals, 
  

   being 
  22-4: 
  per 
  cent. 
  He 
  proved 
  that 
  the 
  disease 
  is 
  necessarily 
  a 
  wound 
  

   infection. 
  In 
  1906 
  also 
  Lingard 
  stated 
  that 
  cattle 
  are 
  the 
  reservoirs, 
  

   carrying 
  the 
  Trypanosome 
  for 
  nine 
  to 
  twelve 
  months 
  and 
  that 
  Tabanidse 
  

   and 
  Hippoboscidee 
  play 
  an 
  important 
  part 
  in 
  the 
  dissemination 
  of 
  Surra, 
  

   but 
  that 
  HcBmatopinus 
  catneli 
  appears 
  in 
  some 
  instances 
  to 
  be 
  the 
  inter- 
  

   mediate 
  host 
  ; 
  Lingard 
  experimented 
  with 
  Tabanus 
  " 
  tropicus," 
  Stomoxys 
  

   and 
  Hippoboscidee 
  and 
  found 
  no 
  species 
  capable 
  of 
  carrying 
  the 
  disease 
  

   during 
  the 
  non-Surra 
  time 
  of 
  year 
  ; 
  the 
  question 
  of 
  transmission 
  by 
  

   leeches 
  was 
  considered 
  and 
  left 
  open 
  for 
  lack 
  of 
  evidence 
  ; 
  he 
  stated 
  

   that 
  canines 
  may 
  help 
  to 
  form 
  the 
  reservoirs 
  during 
  the 
  non-Surra 
  

   period, 
  as 
  they 
  show 
  the 
  disease 
  from 
  January 
  to 
  April, 
  and 
  that 
  rats 
  

   all 
  harbour 
  immature 
  forms 
  of 
  the 
  parasite 
  and 
  their 
  blood 
  is 
  virulent 
  

   when 
  inoculated, 
  so 
  that 
  rat-fleas 
  may 
  possibly 
  carry 
  the 
  disease 
  on 
  

   rare 
  occasions. 
  

  

  Holmes 
  (1906) 
  discussed 
  all 
  the 
  theories, 
  including 
  that 
  of 
  mechanical 
  

   transmission, 
  and 
  decided 
  that 
  they 
  were 
  all 
  inconclusive 
  ; 
  whilst 
  not 
  

   stating 
  that 
  a 
  developmental 
  cycle 
  occurs 
  in 
  the 
  invertebrata, 
  he 
  con- 
  

   sidered 
  that 
  that 
  was 
  the 
  best 
  line 
  of 
  research 
  to 
  pursue. 
  

  

  Patton 
  (1909) 
  described 
  the 
  life-cycle 
  of 
  Crithidia 
  tabani, 
  a 
  flagellate 
  

   found 
  in 
  the 
  intestinal 
  tracts 
  of 
  Tabanus 
  hilaris 
  and 
  of 
  an 
  unnamed 
  

   Tabanus, 
  and 
  it 
  is 
  at 
  least 
  suggestive 
  that 
  this 
  parasite 
  was 
  not 
  found 
  

   in 
  flower-feeding 
  Tabanidse 
  and 
  mammalian 
  blood 
  would 
  thus 
  appear 
  

   essential 
  to 
  its 
  development. 
  [With 
  regard 
  to 
  this 
  paper 
  we 
  would 
  

   remark 
  that 
  the 
  cycle 
  as 
  shown 
  on 
  the 
  place 
  seems 
  correct 
  but, 
  whilst 
  

   there 
  is 
  nothing 
  in 
  the 
  figures 
  to 
  prevent 
  the 
  stages 
  shown 
  from 
  being 
  

   those 
  of 
  a 
  Trypanosome 
  at 
  some 
  period 
  of 
  its 
  lifehi 
  story, 
  on 
  the 
  other 
  

   hand 
  there 
  is 
  nothing 
  to 
  suggest 
  that 
  they 
  are.] 
  

  

  Leese 
  (1909) 
  wrote 
  a 
  long 
  and 
  important 
  paper 
  on 
  experiments 
  

   regarding 
  the 
  natural 
  transmission 
  of 
  Surra, 
  carried 
  out 
  at 
  Mohand 
  in 
  

   1908. 
  This 
  paper 
  was 
  subsequently 
  reissued 
  in 
  Memoir 
  No. 
  2 
  of 
  the 
  

   Civil 
  Veterinary 
  Department 
  and 
  this 
  reissue 
  was 
  illustrated 
  by 
  coloured 
  

   figures 
  of 
  the 
  Tabanid 
  flies 
  found. 
  Some 
  of 
  the 
  specimens 
  of 
  these 
  

  

  * 
  Better 
  an 
  interrupted 
  feeding 
  on 
  the 
  same 
  animal. 
  

  

  