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  CONTAGIOUS 
  DISEASES 
  OF 
  THE 
  CHINCH-BUG. 
  

  

  Champaign, 
  and 
  went 
  over 
  the 
  subject 
  with 
  Prof. 
  T. 
  J. 
  Burrill, 
  of 
  the 
  Industrial 
  

   University 
  there, 
  well 
  known 
  as 
  an 
  authority 
  on 
  everything 
  relating 
  to 
  bacteria 
  

   An 
  abundance 
  of 
  the 
  organisms 
  already 
  mentioned 
  were 
  found 
  in 
  the 
  fluids 
  of 
  

   chinch-bugs 
  examined, 
  but 
  nothing 
  new 
  was 
  discovered. 
  We 
  also 
  determined 
  posi- 
  

   tively 
  the 
  absence 
  of 
  any 
  similar 
  organisms 
  in 
  the 
  juices 
  of 
  the 
  corn. 
  

  

  A 
  series 
  of 
  observations 
  were 
  made 
  which 
  disclosed 
  the 
  fact 
  that 
  the 
  micro- 
  

   organisms 
  were 
  entirely 
  independent 
  of 
  the 
  food 
  ingested, 
  "a 
  fact," 
  declares 
  

   Professor 
  Forbes, 
  " 
  which 
  placed 
  them 
  definitely 
  in 
  the 
  category 
  of 
  parasites." 
  

   Observations 
  were 
  also 
  made 
  determining 
  the 
  comparative 
  absence 
  of 
  bacteria 
  

   from 
  the 
  fluids 
  of 
  bugs 
  taken 
  from 
  fields 
  in 
  which 
  no 
  epidemic 
  was 
  in 
  prog- 
  

   ress, 
  and 
  the 
  constant 
  appearance 
  of 
  the 
  micro-organism 
  in 
  great 
  numbers 
  in 
  

   the 
  fluids 
  of 
  bugs 
  taken 
  from 
  fields 
  in 
  which 
  the 
  insects 
  were 
  rapidly 
  dying. 
  

  

  " 
  Believing 
  that 
  I 
  had 
  now 
  obtained," 
  continues 
  Professor 
  Forbes, 
  " 
  a 
  defi- 
  

   nite 
  proof 
  as 
  was 
  possible 
  by 
  this 
  method 
  that 
  the 
  bacteria 
  observed 
  were 
  the 
  

   cause 
  of 
  the 
  remarkable 
  diminution 
  of 
  the 
  bugs 
  in 
  one 
  of 
  these 
  fields, 
  I 
  next 
  

   attempted 
  the 
  artificial 
  cultivation 
  of 
  the 
  microphytes, 
  with 
  a 
  view 
  to 
  getting 
  

   them 
  free 
  from 
  mixture 
  with 
  other 
  substances, 
  for 
  more 
  careful 
  and 
  conven- 
  

   ient 
  study." 
  Professor 
  Forbes 
  was 
  able 
  to 
  get 
  probably 
  pure 
  cultures 
  in 
  beef 
  

   infusions, 
  and 
  from 
  a 
  slide 
  of 
  mounted 
  and 
  stained 
  organisms 
  from 
  one 
  of 
  

   these 
  cultures 
  Prof. 
  T. 
  J. 
  Burrill, 
  botanist 
  and 
  bacteriologist, 
  of 
  the 
  Univer- 
  

   sity 
  of 
  Illinois, 
  described 
  and 
  named 
  this 
  bacterial 
  parasite 
  of 
  the 
  chinch-bug. 
  

   Professor 
  BurrilPs 
  description 
  is 
  as 
  follows: 
  "Cells 
  obtusely 
  oval, 
  isolated 
  or 
  

   in 
  pairs, 
  rarely 
  in 
  chains 
  of 
  several 
  articles 
  ; 
  .000022 
  inch 
  wide, 
  and 
  .000027 
  

   to 
  .00004 
  inch 
  long, 
  usually 
  about 
  .000032 
  inch 
  long; 
  movements 
  oscillatory 
  

   only; 
  forming 
  zoogloea 
  (?) 
  in 
  the 
  digestive 
  organs 
  of 
  chinch-bugs 
  (Blissus 
  

   leucopterus)." 
  The 
  name 
  given 
  is 
  Micrococcus 
  insectorum. 
  

  

  Before 
  Professor 
  Forbes 
  could 
  attempt 
  his 
  proposed 
  infection 
  experiments, 
  

   "the 
  general 
  disappearance 
  of 
  the 
  chinch-bug," 
  as 
  he 
  said, 
  "and 
  the 
  conse- 
  

   quent 
  difficulty 
  of 
  obtaining 
  specimens 
  for 
  experiment, 
  put 
  a 
  period 
  to 
  the 
  

   investigation, 
  and 
  the 
  solution 
  of 
  the 
  questions 
  still 
  remaining 
  was 
  necessarily 
  

   postponed 
  to 
  another 
  year." 
  

  

  At 
  the 
  same 
  time 
  (August, 
  1882), 
  Professor 
  Forbes 
  first 
  made 
  acquaintance 
  

   with 
  the 
  entomophthorous 
  parasite, 
  which 
  is 
  one 
  of 
  three 
  diseases 
  now 
  main- 
  

   tained 
  in 
  my 
  laboratory 
  and 
  distributed 
  therefrom. 
  I 
  quote 
  from 
  the 
  twelfth 
  

   report 
  (see 
  p. 
  53), 
  as 
  follows: 
  

  

  Besides 
  this 
  bacterium, 
  another 
  parasitic 
  fungus, 
  certainly 
  destructive 
  in 
  character, 
  

   was 
  found 
  to 
  infest 
  the 
  chinch-bug; 
  and 
  this 
  seems 
  to 
  me 
  more 
  likely 
  than 
  the 
  other 
  

   to 
  have 
  been 
  concerned 
  in 
  the 
  wholesale 
  disappearance 
  of 
  the 
  bugs 
  described 
  by 
  Dr. 
  

   Shimer. 
  I 
  have 
  already 
  mentioned 
  the 
  occur»ence 
  of 
  many 
  dead 
  specimens 
  in 
  a 
  field 
  

   at 
  Jacksonville, 
  attached 
  to 
  the 
  stalks 
  and 
  leaves 
  of 
  the 
  corn 
  and 
  buried 
  in 
  the 
  silk. 
  

   These 
  were 
  all 
  imbedded 
  in 
  a 
  dense 
  mat 
  of 
  white 
  fungus 
  threads, 
  which 
  sometimes 
  

   almost 
  hid 
  the 
  body. 
  The 
  general 
  resemblance 
  of 
  this 
  growth 
  to 
  the 
  fungus 
  which 
  

   commonly 
  attacks 
  flies 
  in 
  autumn, 
  often 
  fastening 
  them 
  to 
  the 
  window-pane 
  and 
  

   bursting 
  from 
  their 
  bodies 
  in 
  the 
  form 
  of 
  white 
  efflorescence, 
  led 
  me 
  to 
  suppose 
  that 
  

   this 
  chinch-bug 
  fungus 
  was 
  one 
  of 
  the 
  same 
  character, 
  and 
  not 
  a 
  simple 
  mould, 
  form- 
  

   ing 
  after 
  death. 
  The 
  bugs 
  affected 
  were 
  both 
  pupae 
  and 
  adults. 
  Subsequent 
  study 
  

  

  