﻿PEOCEEDINGS 
  OF 
  THE 
  FOURTH 
  ENTOMOLOGICAL 
  MEETING 
  229 
  

  

  gives 
  no 
  details 
  as 
  to 
  whether 
  they 
  were 
  bred 
  from 
  the 
  egg 
  or 
  from 
  larvge 
  

   collected]. 
  

  

  Patton 
  and 
  Cragg 
  (1913) 
  quote 
  another 
  paper 
  by 
  Mitzmain 
  which 
  

   we 
  have 
  not 
  seen 
  and 
  state 
  that 
  he 
  " 
  has 
  recently 
  carried 
  out 
  a 
  long 
  

   series 
  of 
  experiments 
  with 
  this 
  fly 
  [Stomoxys 
  calcitrans] 
  in 
  order 
  to 
  settle 
  

   this 
  question 
  [the 
  carriage 
  of 
  the 
  trypanosome 
  of 
  Suna.] 
  His 
  results 
  

   indicate 
  that 
  Trypanosoma 
  evansi 
  does 
  not 
  develop 
  in 
  Stomoxys 
  calcitrans, 
  

   and 
  that 
  it 
  plays 
  no 
  part 
  in 
  the 
  transmission 
  of 
  the 
  parasite." 
  

  

  We 
  may 
  here 
  perhaps 
  refer 
  to 
  some 
  unpublished 
  work 
  carried 
  out 
  

   at 
  Bareilly 
  and 
  Kathgodam 
  by 
  the 
  late 
  A. 
  W. 
  Shilston 
  and 
  P. 
  G. 
  Patel 
  

   who 
  found 
  that 
  Tahanus 
  albimedius 
  and 
  T. 
  striatvs 
  could 
  infect 
  by 
  com- 
  

   plete 
  as 
  well 
  as 
  by 
  interrupted 
  feeding 
  [Presumably 
  caught 
  flies 
  were 
  used, 
  

   which 
  would 
  show 
  that 
  these 
  are 
  infective 
  over 
  a 
  considerable 
  period, 
  

   as 
  they 
  only 
  feed 
  every 
  few 
  days]. 
  T. 
  albimedius 
  was 
  found 
  to 
  be 
  infec- 
  

   tive 
  24 
  hours 
  after 
  feeding 
  but 
  not 
  after 
  a 
  longer 
  period. 
  T. 
  siriatus 
  

   was 
  found 
  to 
  carry 
  trypanosomes 
  after 
  72 
  hours. 
  Another 
  small 
  species 
  

   of 
  Tahanus 
  (like 
  virgo) 
  was 
  not 
  found 
  to 
  carry. 
  Experiments 
  with 
  

   Phil(Bmatomyia 
  crassirostris 
  showed 
  that 
  this 
  fly 
  did 
  not 
  infect 
  after 
  a 
  

   longer 
  interval 
  than 
  7 
  minutes 
  during 
  an 
  interrupted 
  feed, 
  but, 
  in 
  the 
  

   case 
  of 
  male 
  flies 
  only, 
  trypanosomes 
  were 
  found 
  active 
  in 
  the 
  gut 
  up 
  

   to 
  28 
  hours 
  after 
  feeding, 
  and 
  the 
  gut 
  contents, 
  when 
  injected 
  into 
  

   guinea 
  pigs 
  after 
  24 
  hours, 
  proved 
  infective 
  ; 
  in 
  the 
  case 
  of 
  the 
  female 
  

   flies, 
  the 
  trypanosome 
  was 
  found 
  to 
  die 
  off 
  in 
  2 
  hours. 
  

  

  Cross 
  (1917) 
  gives 
  a 
  general 
  account 
  of 
  Surra 
  in 
  the 
  camel 
  and 
  states 
  

   that 
  " 
  in 
  order 
  for 
  Surra 
  to 
  spread 
  two 
  factors 
  are 
  necessary 
  : 
  — 
  

  

  (1) 
  the 
  reservoir 
  {i.e., 
  a 
  camel 
  infected 
  with 
  surra) 
  

  

  (2) 
  the 
  transmitting 
  agent 
  {i.e., 
  bloodsucking 
  flies, 
  the 
  most 
  im- 
  

   portant 
  of 
  which 
  as 
  transmitters 
  are 
  the 
  Tabanidse. 
  

  

  " 
  If 
  either 
  of 
  these 
  two 
  factors 
  are 
  wanting, 
  the 
  disease 
  cannot 
  be 
  

   spread 
  from 
  the 
  surra-infected 
  animals 
  to 
  the 
  healthy. 
  If, 
  on 
  the 
  

   other 
  hand, 
  there 
  is 
  a 
  surra-infected 
  camel 
  amongst 
  a 
  batch 
  of 
  healthy 
  

   camels 
  and 
  Tabanidse 
  are 
  present, 
  the 
  fly 
  while 
  sucking 
  the 
  blood 
  (con- 
  

   taining 
  the 
  Trypanosome) 
  from 
  the 
  surra-infected 
  animal 
  may 
  be 
  dis- 
  

   lodged 
  and 
  infect 
  a 
  healthy 
  camel 
  ; 
  during 
  the 
  act 
  of 
  biting 
  this 
  camel, 
  

   he 
  inoculates 
  the 
  latter 
  with 
  surra. 
  This 
  is 
  known 
  as 
  direct 
  or 
  mecha- 
  

   nical 
  transmission. 
  It 
  has 
  been 
  proved 
  by 
  experiment 
  that 
  Surra 
  

   can 
  be 
  transmitted 
  in 
  this 
  ivay, 
  and 
  under 
  favourable 
  conditions 
  {e.g., 
  

   when 
  camels, 
  amongst 
  which 
  are 
  surra-infected 
  ones, 
  are 
  herded 
  together 
  

   and 
  blood-sucking 
  flies 
  are 
  present) 
  there 
  is 
  no 
  reason 
  why 
  the 
  disease 
  

   should 
  not 
  be 
  transmitted 
  in 
  this 
  way 
  ; 
  but 
  whether 
  this 
  is 
  the 
  usual 
  

   method 
  of 
  transmission 
  or 
  whether 
  the 
  trypanosome 
  does 
  not 
  undergo 
  

   a 
  cycle 
  in 
  the 
  fly 
  is 
  still 
  undecided 
  . 
  . 
  7 
  

  

  