﻿HISTORY 
  OF 
  THE 
  DISEASES 
  IN 
  THE 
  UNITED 
  STATES. 
  197 
  

  

  with 
  the 
  microscope 
  demonstrated 
  the 
  correctness 
  of 
  the 
  above 
  surmise, 
  as 
  the 
  fungus 
  

   in 
  question 
  proved 
  to 
  belong 
  to 
  the 
  same 
  genus 
  (Entomophthora) 
  as 
  that 
  infesting 
  

   flies; 
  a 
  fact 
  of 
  which 
  I 
  was 
  assured 
  by 
  Professor 
  Burrill, 
  to 
  whom 
  some 
  specimens 
  

   were 
  submitted. 
  It 
  was 
  not 
  possible 
  to 
  determine 
  the 
  species 
  of 
  the 
  fungus 
  in 
  the 
  

   stage 
  represented 
  by 
  my 
  collections, 
  but 
  it 
  was 
  apparently 
  different 
  from 
  that 
  of 
  the 
  

   house 
  fly. 
  Recent 
  studies 
  of 
  these 
  fungi 
  by 
  European 
  biologists 
  have 
  confirmed 
  the 
  

   prevailing 
  opinion 
  that 
  they 
  are 
  true 
  destructive 
  parasites, 
  the 
  causes 
  and 
  not 
  the 
  

   consequences 
  of 
  disease 
  and 
  death. 
  It 
  seems 
  not 
  impossible 
  that 
  the 
  white 
  mould, 
  

   of 
  which 
  Dr. 
  Shimer 
  speaks 
  in 
  the 
  paragraph 
  I 
  have 
  cited, 
  was 
  really 
  this 
  parasitic 
  

   fungus; 
  and, 
  if 
  so, 
  it 
  was 
  probably 
  the 
  cause 
  of 
  the 
  epidemic 
  disease 
  which 
  he 
  de- 
  

   scribes. 
  This 
  fungus 
  often 
  runs 
  its 
  course 
  to 
  a 
  fatal 
  result 
  without 
  making 
  any 
  ex- 
  

   ternal 
  appearance, 
  bursting 
  forth 
  only 
  after 
  death. 
  It 
  is 
  proper 
  to 
  say, 
  however, 
  that 
  

   I 
  also 
  found 
  three 
  or 
  four 
  dead 
  bugs 
  at 
  Normal, 
  seemingly 
  in 
  the 
  same 
  condition 
  as 
  

   those 
  above 
  described, 
  but 
  which 
  were 
  really 
  simply 
  buried 
  in 
  a 
  harmless 
  mould, 
  as 
  

   was 
  easily 
  seen 
  with 
  the 
  microscope. 
  The 
  parasitic 
  forms 
  are 
  distinguished 
  from 
  the 
  

   moulds 
  at 
  a 
  glance, 
  by 
  the 
  fact 
  that 
  in 
  the 
  former 
  the 
  threads 
  are 
  not 
  divided 
  off 
  into 
  

   cells 
  by 
  cross 
  partitions, 
  as 
  they 
  are 
  in 
  the 
  latter.' 
  

  

  Professor 
  Forbes 
  then 
  quotes 
  at 
  length 
  from 
  an 
  article 
  by 
  MetschnikofF, 
  

   Zoologischer 
  Anzeiger, 
  1880, 
  pp. 
  44-47, 
  in 
  which 
  this 
  eminent 
  biologist 
  bears 
  

   witness 
  to 
  the 
  destructive 
  capability 
  of 
  parasitic 
  fungi, 
  which 
  he 
  found 
  in- 
  

   festing 
  various 
  beetles. 
  MetschnikofF 
  attempted 
  to 
  spread 
  one 
  of 
  the 
  fungus 
  

   diseases 
  artificially, 
  and 
  he 
  "tells 
  of 
  his 
  success 
  in 
  inducing 
  the 
  growth 
  of 
  the 
  

   fungus 
  in 
  artificial 
  media. 
  In 
  concluding 
  his 
  remarks 
  on 
  the 
  subject 
  of 
  con- 
  

   tagious 
  diseases 
  among 
  chinch-bugs, 
  Professor 
  Forbes 
  says 
  : 
  

  

  By 
  Doctor 
  Shimer, 
  the 
  enormous 
  destruction 
  of 
  chinch-bugs 
  in 
  1866 
  [1865] 
  was 
  as- 
  

   cribed 
  to 
  the 
  direct 
  effect 
  of 
  the 
  wet 
  and 
  cool 
  weather. 
  By 
  Mr. 
  Walsh, 
  who 
  discredited 
  

   the 
  idea 
  of 
  an 
  epidemic 
  or 
  contagious 
  disease, 
  it 
  was 
  accounted 
  for 
  as 
  the 
  direct 
  effect 
  

   of 
  moisture. 
  The 
  phenomena 
  connected 
  with 
  the 
  action 
  of 
  parasites, 
  which 
  I 
  have 
  

   above 
  described, 
  were 
  apparently 
  independent 
  of 
  any 
  appreciable 
  general 
  cause, 
  as 
  

   they 
  were 
  most 
  manifest 
  at 
  a 
  time 
  when 
  the 
  weather 
  had 
  been 
  warm, 
  dry, 
  and 
  alto- 
  

   gether 
  unexceptionable 
  for 
  from 
  one 
  to 
  two 
  months. 
  It 
  is 
  not 
  unlikely, 
  however, 
  

   that 
  wet 
  weather 
  may 
  have 
  the 
  effect 
  to 
  stimulate 
  the 
  development 
  of 
  this 
  parasite, 
  

   either 
  directly 
  or 
  indirectly 
  — 
  a 
  hypothesis 
  which 
  will 
  reconcile 
  all 
  the 
  facts 
  now 
  

   known, 
  as 
  well 
  as 
  the 
  conflicting 
  explanations 
  of 
  them 
  which 
  have 
  hitherto 
  been 
  

   put 
  forth. 
  . 
  . 
  . 
  Evidence 
  is 
  adduced 
  of 
  the 
  possibility 
  of 
  artificially 
  cultivating 
  

   this 
  parasite 
  also, 
  and 
  applying 
  it 
  to 
  the 
  destruction 
  of 
  insects. 
  

  

  In 
  the 
  American 
  Naturalist, 
  also, 
  October, 
  1882, 
  Vol. 
  xvi, 
  p. 
  224, 
  Profes- 
  

   sor 
  Forbes 
  gave 
  some 
  account 
  of 
  these 
  observations. 
  

  

  The 
  first 
  observations 
  which 
  seem 
  to 
  indicate 
  the 
  presence 
  of 
  epidemic 
  

   chinch-bug 
  diseases 
  in 
  Kansas 
  are 
  recorded 
  in 
  an 
  article 
  by 
  Prof. 
  E. 
  A. 
  Pope- 
  

   noe, 
  printed 
  in 
  the 
  Prairie 
  Farmer, 
  November 
  25, 
  1882. 
  In 
  this 
  article 
  Pro- 
  

   fessor 
  Popenoe 
  notes 
  the 
  great 
  abundance 
  of 
  the 
  chinch-bug 
  in 
  Kansas 
  in 
  the 
  

   early 
  spring 
  months. 
  The 
  season 
  on 
  the 
  whole, 
  however, 
  proved 
  to 
  be 
  unusu- 
  

   ally 
  free 
  from 
  damage. 
  There 
  was 
  an 
  abundance 
  of 
  rain. 
  

  

  Professor 
  Popenoe 
  thinks 
  it 
  possible 
  that 
  simple 
  excess 
  of 
  moisture 
  may 
  

   have 
  drowned 
  the 
  young 
  bugs 
  on 
  the 
  ground, 
  but 
  doubts 
  if 
  older 
  ones 
  are 
  so 
  

   affected. 
  He 
  gives 
  several 
  instances 
  illustrating 
  the 
  well-known 
  tenacity 
  of 
  

   life 
  in 
  chinch-bugs. 
  He 
  recalls 
  Doctor 
  Shimer's 
  theory 
  of 
  epidemic 
  disease, 
  

  

  —13 
  

  

  