﻿232 
  PROCrKDINGS 
  OF 
  THE 
  FOrHTH 
  ENTOMOLOGICAL 
  MEETING 
  

  

  to 
  be 
  some 
  inverse 
  relation 
  between 
  the 
  two, 
  for 
  out 
  of 
  six 
  hundred 
  

   flies 
  at 
  Jinja, 
  in 
  only 
  3-4 
  per 
  cent, 
  of 
  flies 
  containing 
  bacilli 
  were 
  Try- 
  

   panosomes 
  also 
  found, 
  and 
  in 
  only 
  6-1 
  per 
  cent, 
  of 
  flies 
  containing 
  

   Trypanosomes 
  were 
  bacilli 
  found. 
  Bacilli 
  were 
  present 
  in 
  19-3 
  per 
  

   cent, 
  and 
  Trypanosomes 
  in 
  11 
  per 
  cent, 
  of 
  the 
  wild 
  flies. 
  Thus 
  there 
  

   is 
  marked 
  incompatibility 
  between 
  the 
  two. 
  

  

  " 
  Since 
  I 
  have 
  found 
  bacilli 
  in 
  the 
  gut 
  of 
  freshly 
  hatched 
  flies, 
  and 
  

   even 
  in 
  pupse, 
  their 
  presence 
  in 
  the 
  fly 
  may 
  have 
  something 
  to 
  do 
  with 
  

   the 
  fact 
  that 
  only 
  a 
  few 
  out 
  of 
  a 
  batch 
  of 
  flies 
  fed 
  upon 
  an 
  infected 
  animal 
  

   at 
  the 
  same 
  time 
  will 
  prove 
  suitable 
  hosts 
  and 
  will 
  subsequently 
  be 
  

   found 
  to 
  contain 
  Trypanosomes. 
  It 
  may 
  be 
  that 
  the 
  presence 
  of 
  bacilli 
  

   in 
  numbers 
  is 
  inimicnl 
  to 
  the 
  Trypanosomes, 
  or 
  merely 
  that 
  they 
  are 
  

   present 
  in 
  flies 
  which 
  for 
  some 
  other 
  reason 
  are 
  physiologically 
  unsuited 
  

   to 
  the 
  development 
  in 
  them 
  of 
  the 
  Trypanosomes 
  " 
  (Carpenter, 
  pp. 
  

   4041). 
  

  

  In 
  a 
  recent 
  paper 
  R. 
  W. 
  Glaser 
  (1920) 
  has 
  summarized 
  the 
  literature 
  

   on 
  intracellular 
  non-pathogenic 
  organisms 
  found 
  in 
  insects 
  and 
  states 
  

   that 
  these 
  are 
  found 
  to 
  occur 
  in 
  Blattidse, 
  Homoptera, 
  Formicidae, 
  

   and 
  certain 
  Lepidoptera 
  and 
  Coleoptera. 
  It 
  would 
  be 
  interesting 
  to 
  

   ascertain 
  whether 
  similar 
  bacilli 
  occur 
  in 
  bloodsucking 
  flies 
  other 
  than 
  

   Glossina 
  and 
  whether 
  their 
  occurrence 
  or 
  absence 
  bears 
  any 
  relation 
  

   to 
  the 
  portability 
  of 
  Trypanosomes 
  in 
  such 
  flies. 
  Cross 
  (1917), 
  for 
  

   example, 
  in 
  the 
  passage 
  we 
  have 
  already 
  quoted 
  comments 
  on 
  the 
  pro- 
  

   bability 
  that 
  only 
  a 
  percentage 
  of 
  potential 
  carrier-flies 
  are 
  capable 
  of 
  

   infecting 
  healthy 
  camels 
  with 
  Surra, 
  but 
  no 
  one 
  seems 
  to 
  have 
  noticed 
  

   whether 
  such 
  intracellular 
  bacteria 
  occur 
  in 
  biting 
  flies 
  in 
  India. 
  

  

  We 
  may 
  now 
  indicate 
  briefly 
  what 
  we 
  consider 
  is 
  required 
  to 
  be 
  

   done 
  to 
  investigate 
  the 
  question 
  of 
  Surra 
  in 
  India. 
  Assuming 
  that 
  

   Surra 
  is 
  carried 
  in 
  natural 
  reservoirs 
  which 
  are 
  domesticated 
  or 
  wild 
  

   animals 
  and 
  that 
  it 
  is 
  transmitted 
  to 
  domesticated 
  animals 
  by 
  biting 
  

   flies, 
  we 
  require 
  definite 
  knovdedge 
  regarding 
  (a) 
  the 
  biting 
  flies 
  con- 
  

   cerned 
  and 
  (6) 
  the 
  normal 
  method 
  of 
  transmission. 
  As 
  regards 
  the 
  

   biting 
  flies 
  we 
  require 
  a 
  thorough 
  survey 
  of 
  the 
  various 
  species 
  of 
  Taba- 
  

   nidse 
  and 
  other 
  biting 
  flies 
  which 
  occur 
  throughout 
  the 
  Indian 
  Region. 
  

   At 
  present 
  our 
  knowledge 
  of 
  the 
  Indian 
  Tabanidse, 
  to 
  take 
  an 
  example, 
  

   is 
  extremely 
  scrappy 
  and 
  defective. 
  ' 
  We 
  know 
  that 
  about 
  131 
  species 
  

   have 
  been 
  described 
  as 
  occurring 
  within 
  Indian 
  limits 
  and 
  these 
  have 
  

   been 
  placed 
  in 
  about 
  13 
  genera, 
  but 
  it 
  is 
  probable 
  that 
  a 
  proper 
  survey 
  

   would 
  bring 
  the 
  number 
  of 
  species 
  up 
  to 
  nearer 
  two 
  hundred. 
  Even 
  

   of 
  those 
  we 
  do 
  know, 
  there 
  is 
  extremely 
  little 
  on 
  record 
  regarding 
  their 
  

   distribution, 
  life 
  histories 
  and 
  bionomics 
  generally. 
  The 
  early 
  stages 
  

  

  