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  tion 
  of 
  reproduction 
  by 
  the 
  adults 
  at 
  the 
  time 
  of 
  the 
  heavy 
  rains. 
  

   In 
  fact, 
  the 
  number 
  of 
  dead 
  actually 
  seen 
  by 
  the 
  observers 
  in 
  this 
  

   district 
  seems 
  insufficient 
  to 
  account, 
  even 
  on 
  the 
  most 
  liberal 
  inter- 
  

   pretation 
  of 
  the 
  facts, 
  for 
  all 
  this 
  apparent 
  diminution. 
  

  

  Certainly 
  there 
  was 
  no 
  good 
  reason 
  to 
  suppose 
  that 
  contagious 
  dis- 
  

   eases 
  had 
  any 
  very 
  important 
  share 
  in 
  the 
  destruction 
  of 
  the 
  chinch- 
  

   bug 
  at 
  this 
  place. 
  This 
  was 
  shown 
  not 
  merely 
  by 
  field 
  observations, 
  

   but 
  likewise 
  by 
  our 
  lal)oratory 
  experiments, 
  in 
  which 
  a 
  hundred 
  and 
  

   five 
  dead 
  bugs 
  placed 
  under 
  conditions 
  to 
  develop 
  the 
  fungi 
  of 
  mus- 
  

   cardine 
  gave 
  only 
  one 
  case 
  of 
  a 
  fungus 
  parasite 
  {Entomophthora 
  

   aphidis). 
  An 
  attempt 
  to 
  infect 
  chinch-bugs' 
  eggs 
  with 
  this 
  fungus 
  

   failed 
  completely. 
  

  

  July 
  was 
  rather 
  dry 
  until 
  the 
  IDth. 
  Among 
  a 
  thousand 
  dead 
  

   placed 
  at 
  this 
  time 
  on 
  moist 
  sand, 
  less 
  than 
  fifty 
  exhibited 
  any 
  para- 
  

   sitic 
  fungus 
  growth, 
  those 
  with 
  white 
  muscardine 
  (Sporotrichum) 
  

   being 
  three 
  times 
  as 
  abundant 
  as 
  those 
  with 
  green 
  (Entomophthora) 
  . 
  

   On 
  the 
  other 
  hand, 
  a 
  very 
  large 
  number 
  of 
  these 
  chinch-bugs 
  when 
  so 
  

   treated 
  underwent 
  a 
  peculiar 
  decomposition, 
  indicating 
  beyond 
  doubt 
  

   the 
  presence 
  of 
  a 
  bacterial 
  infection 
  — 
  whether 
  septic 
  or 
  pathogenic 
  

   originally 
  it 
  is 
  impossible 
  to 
  say. 
  In 
  a 
  collection 
  of 
  such 
  insects 
  

   taken 
  from 
  an 
  observation 
  box 
  at 
  the 
  same 
  time 
  (all 
  of 
  which 
  had 
  

   died 
  within 
  twenty-four 
  hours) 
  and 
  placed 
  on 
  moist 
  sand 
  together 
  

   in 
  a 
  Petri 
  dish, 
  a 
  large 
  j)ercentage 
  became 
  swollen 
  and 
  soft, 
  with 
  

   whitish 
  or 
  greenish 
  abdomens 
  which 
  presently 
  burst, 
  exuding 
  a 
  

   creamy 
  or 
  slightly 
  discolored 
  fluid 
  swarming 
  with 
  various 
  forms 
  of 
  

   bacteria. 
  Most 
  of 
  the 
  others 
  remained 
  without 
  notable 
  change. 
  

  

  A 
  considerable 
  amount 
  of 
  microscopic 
  study 
  of 
  the 
  decomposing 
  

   specimens 
  resulted 
  in 
  no 
  discovery 
  of 
  any 
  common 
  character 
  of 
  the 
  

   fluids, 
  or 
  of 
  any 
  single 
  bacterial 
  species 
  which 
  could 
  be 
  even 
  hypo- 
  

   thetically 
  connected 
  with 
  their 
  death, 
  and 
  the 
  meaning 
  of 
  these 
  

   X)henomena 
  consequently 
  remains 
  obscure. 
  They 
  doubtless 
  deserve 
  

   further 
  investigation. 
  In 
  this 
  connection 
  I 
  may 
  refer 
  to 
  the 
  dissec- 
  

   tion 
  of 
  a 
  dead 
  chinch-bug 
  from 
  Tamaroa, 
  made 
  July 
  8, 
  and 
  described 
  

   under 
  that 
  date 
  in 
  the 
  detailed 
  abstract 
  of 
  field 
  and 
  laboratory 
  notes, 
  

   on 
  another 
  page. 
  

  

  A 
  still 
  further 
  marked 
  diminution 
  in 
  the 
  number 
  of 
  chinch-bugs 
  

   followed 
  upon 
  very 
  heavy 
  rains 
  Jul}' 
  19 
  and 
  20, 
  many 
  freshly 
  dead 
  

   adults 
  l)eing 
  noticed 
  at 
  this 
  time 
  between 
  leaves 
  and 
  stalks 
  of 
  corn. 
  

   Only 
  a 
  few 
  of 
  these 
  were 
  clearly 
  dead 
  with 
  fungus 
  disease, 
  and 
  the 
  

   cause 
  of 
  death 
  of 
  the 
  others 
  was 
  not 
  apparent. 
  They 
  were 
  quite 
  

   possibly 
  killed 
  by 
  drowning. 
  

  

  The 
  condition 
  of 
  these 
  fields 
  in 
  August 
  was 
  not 
  materially 
  

   changed. 
  Chinch-bugs 
  continued 
  to 
  die, 
  adults 
  predominating,, 
  

   some 
  exhibiting 
  growths 
  of 
  white 
  muscardine 
  after 
  death, 
  but 
  the 
  

   greater 
  number 
  not. 
  

  

  At 
  Odin 
  the 
  situation 
  and 
  the 
  succession 
  of 
  events 
  were 
  not 
  ma- 
  

   terially 
  different 
  from 
  those 
  at 
  Tamaroa, 
  except 
  that 
  some 
  of 
  the 
  

   fields 
  regularly 
  visited 
  were 
  those 
  in 
  which 
  muscardine 
  experiments 
  

  

  