﻿101 
  

  

  most 
  of 
  the 
  latter, 
  however, 
  showing 
  a 
  growth 
  of 
  Sporotrichum, 
  and 
  

   only 
  two 
  of 
  the 
  former. 
  On 
  the 
  29th, 
  on 
  the 
  other 
  hand, 
  the 
  num- 
  

   ber 
  of 
  fungus-covered 
  bugs 
  was 
  approximately 
  the 
  same 
  in 
  the 
  two 
  

   lots. 
  

  

  From 
  this 
  indeterminate 
  experiment 
  we 
  must 
  conclude 
  either 
  that 
  

   Sporotrichum 
  was 
  present 
  in 
  the 
  original 
  lot 
  before 
  division, 
  or 
  that 
  

   the 
  check 
  lot 
  became 
  accidentally 
  infected 
  at 
  or 
  near 
  the 
  beginning 
  

   of 
  the 
  experiment. 
  

  

  A 
  third 
  experiment 
  with 
  the 
  white 
  fungus 
  (Sporotrichum) 
  was 
  

   begun 
  September 
  2, 
  1895, 
  as 
  a 
  basis 
  of 
  comparison 
  with 
  a 
  series 
  of 
  

   experiments 
  made 
  at 
  the 
  same 
  time 
  in 
  the 
  application 
  of 
  several 
  

   other 
  kinds 
  of 
  fungus 
  parasites 
  of 
  insects 
  obtained 
  from 
  Prof. 
  A. 
  

   Giard, 
  of 
  Paris, 
  France. 
  

  

  In 
  this 
  muscardine 
  experiment 
  a 
  small 
  pill-box 
  of 
  living 
  chinch- 
  

   bugs 
  (not 
  counted) 
  were 
  treated 
  as 
  in 
  the 
  foregoing 
  experiments, 
  ex- 
  

   cept 
  that 
  infection 
  was 
  produced 
  by 
  shaking 
  the 
  l)ugs 
  up 
  thoroughly 
  

   with 
  a 
  quantity 
  of 
  dry 
  spores 
  of 
  the 
  muscardine 
  fungus 
  from 
  an 
  ar- 
  

   tificial 
  culture 
  one 
  remove 
  from 
  the 
  dead 
  insect. 
  Four 
  days 
  after 
  

   infection 
  fifty 
  bugs 
  were 
  dead 
  from 
  this 
  lot; 
  three 
  days 
  later, 
  Sep- 
  

   tember 
  9, 
  thirty-three 
  additional 
  dead 
  were 
  removed, 
  and. 
  finally, 
  on 
  

   September 
  12, 
  twelve 
  more, 
  making 
  ninety-five 
  in 
  all 
  within 
  ten 
  days 
  

   Transferred 
  to 
  moist 
  sand, 
  approximately 
  half 
  of 
  them 
  exhibited 
  a 
  

   strong 
  growth 
  of 
  Sporotrichum 
  (jlohidifcrnni. 
  

  

  It 
  has 
  been 
  for 
  some 
  time 
  a 
  favorite 
  surmise 
  of 
  mine 
  that 
  native 
  

   American 
  insects 
  might 
  be 
  found 
  more 
  susceptible 
  to 
  European 
  

   fungus 
  parasites 
  of 
  related 
  species 
  than 
  to 
  American 
  parasitic 
  fungi. 
  

   With 
  a 
  view 
  to 
  testing 
  this 
  supposition, 
  nine 
  European 
  species 
  of 
  

   parasitic 
  fungi* 
  known 
  to 
  infest 
  insects 
  in 
  the 
  Old 
  World 
  were 
  ob- 
  

   tained, 
  — 
  all 
  but 
  one 
  {Isaria 
  deusa) 
  from 
  Prof. 
  A. 
  Giard, 
  of 
  Paris, 
  

   France, 
  — 
  and 
  September 
  2 
  were 
  brought 
  into 
  use 
  in 
  a 
  series 
  of 
  ex- 
  

   periments 
  arranged 
  like 
  those 
  last 
  described. 
  Each 
  parasitic 
  species 
  

   was 
  used 
  in 
  two 
  experiments, 
  observations 
  on 
  which 
  were 
  continued 
  

   for 
  fifteen 
  days. 
  In 
  each 
  of 
  these 
  lots 
  the 
  number 
  of 
  bugs 
  dying 
  

   was 
  recorded, 
  and 
  these 
  dead 
  bugs 
  were 
  transferred 
  to 
  dishes 
  of 
  

   moist 
  sand 
  with 
  a 
  view 
  to 
  obtaining 
  if 
  possible 
  a 
  post-mortem 
  growth 
  

   of 
  the 
  parasite 
  used 
  in 
  the 
  infection. 
  A 
  detailed 
  report 
  on 
  these 
  

   lots 
  of 
  specimens 
  is 
  rendered 
  unnecessary 
  by 
  the 
  fact 
  that 
  in 
  no 
  case 
  

   was 
  such 
  a 
  growth 
  obtained, 
  unless 
  possibly 
  in 
  two 
  lots 
  where 
  Isarid 
  

   (iensa 
  was 
  used. 
  In 
  these 
  a 
  growth 
  appeared 
  upon 
  some 
  of 
  the 
  dead 
  

   bugs, 
  which 
  did 
  not 
  make 
  sufficient 
  progress 
  to 
  permit 
  its 
  determi- 
  

   nation. 
  In 
  all 
  the 
  other 
  cases 
  post-mortem 
  fungi, 
  if 
  developed 
  at 
  all, 
  

   were 
  either 
  the 
  fungus 
  of 
  white 
  muscardine 
  or 
  non-parasitic 
  kinds. 
  

   As 
  an 
  attempt 
  at 
  the 
  introduction 
  of 
  European 
  fungus 
  j)arasites 
  of 
  

   insects 
  these 
  experiments 
  were, 
  consequently, 
  a 
  failure. 
  

  

  Some 
  incidental 
  information 
  of 
  interest 
  was 
  obtained, 
  however, 
  

   with 
  regard 
  to 
  the 
  effect 
  of 
  Sporotrichum 
  globuliferum 
  as 
  applied 
  to 
  

  

  * 
  The 
  fungi 
  used 
  in 
  this 
  experiment 
  belonired 
  to 
  the 
  following: 
  species 
  of 
  Isai-ia: 
  pachy- 
  

   tili, 
  noUtoris, 
  farinosa. 
  cochyliera, 
  arnanltH 
  . 
  oralisporn, 
  d('stri(<-t(ir, 
  dens<t 
  . 
  and 
  one 
  un- 
  

   known. 
  Infections 
  were 
  induced 
  by 
  sliakiuir 
  up 
  the 
  bugs 
  with 
  ;i 
  small 
  quantity 
  of 
  spores 
  

   direct 
  from 
  the 
  original 
  culture 
  received 
  from 
  l-'rofessor 
  (iiurd. 
  

  

  