﻿t*llOCEfit>lNGS 
  OF 
  THIS 
  FOtlRTH 
  ENTOMOLOGICAL 
  MEEtiNG 
  2^3 
  

  

  There 
  is 
  also 
  some 
  evidence 
  that 
  pigs 
  and 
  elephants 
  are 
  naturally 
  infected, 
  

   and 
  it 
  is 
  probable 
  that 
  systematic 
  examination 
  would 
  add 
  other 
  wild 
  

   animals 
  to 
  the 
  list 
  of 
  natural 
  carriers. 
  

  

  Surra 
  is 
  by 
  no 
  means 
  confined 
  to 
  India. 
  It 
  occurs 
  probably 
  through- 
  

   out 
  South-eastern 
  Asia 
  and 
  has 
  been 
  recorded 
  from 
  India, 
  Burma, 
  

   Federated 
  Malay 
  States, 
  Indo-China, 
  the 
  Philippines, 
  Java 
  and 
  Sumatra, 
  

   and 
  also 
  from 
  Mauritius, 
  whither 
  it 
  was 
  imported 
  with 
  Indian 
  cattle. 
  

   A 
  striking 
  point 
  about 
  it 
  is 
  its 
  occurrence 
  in 
  definite 
  areas, 
  commonly 
  

   called 
  Surra 
  belts, 
  which 
  Pease 
  (1906) 
  states 
  are 
  " 
  lowlying 
  marshy 
  

   lands, 
  subject 
  to 
  partial 
  inundation 
  and 
  subsequent 
  partial 
  drying 
  

   up, 
  covered 
  with 
  rough 
  grass 
  and 
  jungle." 
  Such 
  conditions 
  are 
  not, 
  

   however, 
  apparently 
  a 
  necessary 
  accompaniment 
  of 
  an 
  outbreak 
  of 
  

   Surra, 
  as 
  cases 
  have 
  occurred 
  in 
  ponies 
  and 
  dogs 
  in 
  Madras 
  City, 
  where 
  

   they 
  do 
  not 
  exist, 
  and 
  in 
  North 
  Bihar, 
  where 
  such 
  conditions 
  do 
  exist, 
  

   Surra 
  appears 
  to 
  be 
  unknown. 
  Many 
  observers 
  are 
  agreed 
  that 
  the 
  

   limits 
  of 
  Surra 
  belts 
  are 
  sharply, 
  or 
  fairly 
  sharply, 
  defined 
  but 
  there 
  

   seems 
  to 
  be 
  little 
  exact 
  information 
  on 
  record 
  regarding 
  their 
  occurrence 
  

   and 
  delimination 
  in 
  India. 
  In 
  this 
  connection 
  we 
  have 
  prepared 
  a 
  

   map 
  (Plate 
  XL) 
  from 
  the 
  reports 
  on 
  file 
  at 
  Pusa 
  showing 
  the 
  areas 
  in 
  

   which 
  Surra 
  is 
  reported 
  to 
  have 
  occurred 
  during 
  the 
  last 
  ten 
  years*. 
  It 
  

   has 
  not 
  been 
  found 
  possible, 
  in 
  the 
  absence 
  of 
  a 
  standard 
  and 
  from 
  the 
  

   information 
  available, 
  to 
  indicate 
  the 
  intensity 
  of 
  occurrence 
  in 
  any 
  

   area. 
  Further, 
  when 
  studying 
  the 
  map, 
  it 
  gives 
  one 
  the 
  impression 
  

   that 
  many 
  areas 
  shown 
  as 
  isolated 
  are 
  in 
  reality 
  portions 
  of 
  some 
  main 
  

   area 
  and, 
  if 
  more 
  detailed 
  information 
  had 
  been 
  available, 
  would 
  have 
  

   been 
  shown 
  as 
  such. 
  Discontinuity 
  of 
  distribution 
  is 
  probably 
  more 
  

   apparent 
  than 
  real 
  and 
  is 
  probably 
  largely 
  due 
  to 
  absence 
  of 
  reports 
  

   rather 
  than 
  to 
  absence 
  of 
  the 
  disease. 
  Subject 
  to 
  this 
  remark, 
  it 
  will 
  

   be 
  seen 
  that, 
  north 
  of 
  the 
  parallel 
  of 
  Bombay, 
  the 
  disease 
  is 
  absent 
  

   only 
  from 
  the 
  desert 
  areas 
  and 
  from 
  Bihar 
  north 
  of 
  the 
  Ganges. 
  The 
  

   occurrence 
  in 
  South 
  Madras 
  of 
  an 
  isolated 
  area 
  of 
  fairly 
  constant 
  

   infection 
  is 
  most 
  interesting. 
  Surra 
  also 
  occurs 
  in 
  Central 
  Ceylon 
  (not 
  

   shown 
  on 
  the 
  map). 
  

  

  The 
  most 
  interesting 
  and 
  most 
  important 
  point 
  about 
  Surra 
  is 
  with 
  

   regard 
  to 
  its 
  method 
  of 
  transmission 
  from 
  one 
  animal 
  to 
  another. 
  Given 
  

   an 
  animal 
  whose 
  blood 
  contains 
  Trypanosoma 
  evansi 
  and 
  another 
  animal 
  

   whose 
  blood 
  is 
  free 
  from 
  this 
  Trypanosome, 
  how 
  can 
  the 
  parasite 
  pass 
  

   from 
  the 
  infected 
  animal 
  to 
  infect 
  the 
  hitherto 
  healthy 
  one 
  ? 
  Now, 
  

   with 
  regard 
  to 
  this, 
  before 
  considering 
  the 
  various 
  experiments 
  that 
  

   have 
  been 
  done 
  and 
  the 
  theories 
  that 
  have 
  been 
  advanced, 
  we 
  must 
  

  

  * 
  Since 
  this 
  paper 
  was 
  read, 
  Surra 
  has 
  also 
  been 
  reported 
  to 
  occur 
  in 
  Ceylon, 
  which 
  

   should 
  therefore 
  be 
  shaded 
  in 
  the 
  map. 
  — 
  T.B.F. 
  

  

  