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  Third, 
  the 
  origin 
  of 
  the 
  disease. 
  

  

  Fourth, 
  relation 
  of 
  birds 
  and 
  insects 
  to 
  the 
  dissemination 
  

   of 
  the 
  disease. 
  

  

  Fifth, 
  the 
  nature 
  and 
  degree 
  of 
  resistance 
  of 
  the 
  Asiatic 
  spe- 
  

   cies. 
  Another 
  problem 
  in 
  relation 
  to 
  tree 
  treatment 
  may 
  be 
  

   added, 
  that 
  is, 
  the 
  relation 
  of 
  spores 
  and 
  myelium 
  to 
  toxic 
  agents. 
  

  

  The 
  Pennsylvania 
  Commission 
  maintained 
  laboratories 
  dur- 
  

   ing 
  the 
  summer 
  at 
  Charter 
  Oak, 
  Centre 
  County, 
  and 
  at 
  Mt. 
  

   Gretna, 
  Lebanon 
  County. 
  The 
  latter 
  has 
  been 
  moved 
  to 
  Frank- 
  

   lin 
  and 
  Marshall 
  College, 
  Lancaster, 
  for 
  the 
  winter. 
  We 
  have 
  

   also 
  had 
  a 
  laboratory 
  at 
  the 
  University 
  of 
  Pennsylvania, 
  which 
  

   has 
  been 
  greatly 
  enlarged 
  this 
  fall. 
  

  

  The 
  number 
  of 
  people 
  who 
  informed 
  us 
  that 
  they 
  had 
  dis- 
  

   covered 
  a 
  sure 
  "cure" 
  for 
  the 
  blight 
  made 
  it 
  necessary 
  to 
  ob- 
  

   tain 
  an 
  orchard 
  near 
  Philadelphia 
  where 
  all 
  such 
  discoverers 
  

   were 
  given 
  an 
  opportunity 
  to 
  demonstrate 
  the 
  efficacy 
  of 
  their 
  

   remedies. 
  It 
  might 
  be 
  noted 
  that 
  in 
  every 
  case 
  the 
  blight 
  is 
  

   thriving 
  as 
  usual. 
  These 
  cures 
  consisted 
  largely 
  of 
  an 
  injec- 
  

   tion 
  of 
  a 
  toxic 
  principle 
  by 
  some 
  means 
  into 
  the 
  circulation 
  of 
  

   the 
  tree. 
  In 
  some 
  cases 
  this 
  was 
  accompanied 
  by 
  a 
  fertilizer 
  

   of 
  some 
  kind, 
  and 
  this 
  fertilizer 
  may 
  account 
  for 
  the 
  apparently 
  

   improved 
  condition 
  of 
  the 
  tree 
  in 
  some 
  cases, 
  after 
  such 
  remedies 
  

   were 
  used, 
  since 
  the 
  growth 
  was 
  increased 
  and 
  the 
  leaves 
  and 
  

   branches 
  had 
  a 
  healthier 
  appearance. 
  This 
  increased 
  growth 
  

   has 
  not 
  had 
  any 
  appreciable 
  effect 
  upon 
  the 
  rapidity 
  of 
  spread 
  

   of 
  the 
  blight 
  mycelium. 
  As 
  the 
  experiments 
  are 
  not 
  officially 
  

   finished 
  and 
  recorded 
  it 
  is 
  too 
  early 
  to 
  give 
  any 
  further 
  data. 
  

   Our 
  pathologists 
  have 
  also 
  conducted 
  experiments 
  in 
  this 
  same 
  

   line 
  but 
  no 
  medicinal 
  remedy 
  or 
  fertilizer 
  has 
  yet 
  been 
  found. 
  

  

  The 
  varying 
  chemical 
  constituents 
  of 
  chestnut 
  trees, 
  prin- 
  

   cipally 
  tannic 
  acid, 
  have 
  often 
  been 
  suggested 
  in 
  regard 
  to 
  the 
  

   origin 
  and 
  spread 
  of 
  the 
  blight. 
  Investigators 
  are 
  now 
  working 
  

   along 
  this 
  line 
  and 
  we 
  hope, 
  for 
  valuable 
  results 
  before 
  long. 
  

  

  The 
  origin 
  of 
  the 
  disease, 
  as 
  already 
  stated, 
  is 
  something 
  

   of 
  a 
  mystery, 
  and 
  there 
  is 
  as 
  yet 
  no 
  generally 
  accepted 
  theory, 
  

   although 
  many 
  people 
  have 
  very 
  pronounced 
  views 
  on 
  the 
  sub- 
  

   ject. 
  Many 
  puzzling 
  facts 
  have 
  been 
  noted 
  since 
  investigating 
  

   the 
  disease 
  in 
  Pennsylvania, 
  among 
  them 
  being 
  the 
  large 
  per- 
  

   centage 
  of 
  infection 
  in 
  eastern 
  York 
  and 
  southern 
  Lancaster 
  

   counties, 
  the 
  relative 
  small 
  percentage 
  in 
  certain 
  localities 
  around 
  

   which 
  the 
  blight 
  is 
  generally 
  prevalent, 
  and 
  recent 
  infections 
  

   found 
  in 
  Warren 
  and 
  other 
  western 
  counties, 
  a 
  great 
  distance 
  

  

  