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  of 
  two 
  minutes, 
  it 
  will 
  disappear 
  entirely. 
  It 
  is 
  dissipated 
  in 
  the 
  water, 
  

   and 
  the 
  spores 
  are 
  so 
  small 
  you 
  cannot 
  see 
  them 
  with 
  the 
  naked 
  eye. 
  If 
  

   you 
  let 
  th.e 
  water 
  dry 
  on 
  the 
  slide, 
  then 
  put 
  that 
  slide 
  under 
  the 
  micro- 
  

   scope 
  and 
  try 
  to 
  blow 
  those 
  spores 
  off, 
  you 
  can 
  do 
  it 
  just 
  about 
  as 
  easily 
  

   as 
  you 
  can 
  blow 
  the 
  shellac 
  off 
  a 
  door. 
  You 
  can 
  brush 
  that 
  film 
  under 
  

   the 
  microscope, 
  and 
  you 
  can 
  't 
  see 
  that 
  a 
  single 
  spore 
  has 
  been 
  disturbed. 
  

   The 
  explanation. 
  I 
  think, 
  lies 
  in 
  the 
  fact 
  that 
  these 
  spores 
  are 
  of 
  a 
  

   mucilaginous 
  nature, 
  and 
  when 
  they 
  dry, 
  they 
  stick 
  to 
  whatever 
  they 
  

   come 
  in 
  contact 
  with. 
  That 
  does 
  not 
  mean 
  that 
  these 
  spores 
  cannot 
  be 
  

   blown, 
  because 
  they 
  may 
  lie 
  on 
  fragments 
  of 
  leaves 
  and 
  be 
  blown 
  about 
  

   by 
  the 
  wind. 
  Again, 
  some 
  of 
  the 
  spores 
  may 
  be 
  detached 
  in 
  a 
  mechani- 
  

   cal 
  way 
  and 
  and 
  thus 
  blown 
  by 
  the 
  wind. 
  But 
  I 
  am 
  quite 
  convinced 
  

   that 
  the 
  spores 
  are 
  not 
  blown 
  broadcast, 
  simply 
  because 
  they 
  are 
  of 
  a 
  

   sticky 
  nature. 
  

  

  Now, 
  those 
  spore 
  threads 
  are 
  forced 
  out 
  under 
  certain 
  conditions, 
  

   moisture 
  conditions, 
  as 
  a 
  rule. 
  It 
  has 
  been 
  shown 
  after 
  repeated 
  obser- 
  

   vation 
  that 
  these 
  spore 
  threads 
  are 
  pushed 
  out 
  a 
  day 
  or 
  two 
  after 
  a 
  

   rain. 
  Of 
  course, 
  in 
  the 
  springtime, 
  the 
  atmosphere 
  is 
  much 
  more 
  moist 
  

   than 
  later 
  in 
  the 
  season. 
  Consequently, 
  we 
  find 
  more 
  of 
  these 
  spore 
  

   threads 
  in 
  the 
  spring 
  than 
  at 
  any 
  other 
  time. 
  You 
  will 
  recall 
  that 
  the 
  

   last 
  week 
  of 
  August 
  this 
  year 
  was 
  a 
  week 
  of 
  almost 
  continuous 
  rain. 
  

   Two 
  days 
  after 
  that 
  ceased, 
  I 
  saw 
  as 
  many 
  of 
  these 
  spore 
  threads 
  as 
  I 
  

   had 
  seen 
  at 
  any 
  one 
  time 
  all 
  sunnner. 
  So 
  that, 
  although 
  conditions 
  are 
  

   best 
  in 
  the 
  spring 
  for 
  greater 
  abundance 
  of 
  these 
  spores, 
  they 
  may 
  

   occur 
  at 
  any 
  time. 
  If 
  a 
  bird 
  alights 
  on 
  these 
  spore 
  masses, 
  there 
  is 
  no 
  

   reason 
  that 
  I 
  see 
  why 
  they 
  should 
  not 
  be 
  carried. 
  We 
  know 
  the 
  rain 
  

   water 
  running 
  down 
  the 
  trunk 
  dissolves 
  these 
  spore 
  masses, 
  and 
  they 
  

   are 
  carried 
  down, 
  there 
  to 
  reinfect 
  the 
  tree 
  when 
  insects 
  crawl 
  around. 
  

  

  President 
  Morris: 
  My 
  brother 
  has 
  some 
  Japanese 
  chestnuts 
  twenty- 
  

   five 
  or 
  thirty 
  years 
  of 
  age. 
  By 
  cutting 
  off 
  one 
  branch 
  at 
  a 
  time 
  as 
  fast 
  

   as 
  they 
  blighted, 
  he 
  has 
  saved 
  those 
  trees. 
  

  

  Professor 
  Collins 
  : 
  You 
  spoke, 
  Doctor 
  Morris, 
  of 
  grafting 
  Japanese 
  

   on 
  to 
  American 
  stock. 
  I 
  have 
  seen 
  repeated 
  cases 
  where 
  the 
  Japanese 
  

   has 
  been 
  grafted 
  on 
  to 
  American 
  stock. 
  The 
  whole 
  Japanese 
  tree 
  has 
  

   been 
  killed, 
  and 
  we 
  find 
  the 
  disease 
  has 
  killed 
  the 
  tree 
  by 
  girdling 
  the 
  

   American 
  stock 
  below 
  the 
  graft. 
  

  

  President 
  Morris: 
  Yes, 
  I 
  find 
  this 
  over 
  and 
  over 
  again. 
  In 
  one 
  

   case 
  where 
  I 
  had 
  a 
  very 
  choice 
  variety 
  of 
  Burley's 
  chestnut, 
  the 
  

   DiaporfJie 
  attacked 
  the 
  American 
  stock 
  underneath 
  this, 
  and 
  had 
  prac- 
  

   tically 
  girdled 
  it 
  when 
  I 
  saw 
  it. 
  There 
  remained 
  a 
  fraction 
  of 
  an 
  inch 
  

   of 
  good 
  bark. 
  I 
  cut 
  off 
  all 
  except 
  that, 
  and 
  put 
  tar 
  over 
  it, 
  and 
  grafting 
  

   wax 
  over 
  that, 
  and 
  this 
  year 
  the 
  graft 
  has 
  grown 
  a 
  foot 
  or 
  more. 
  So 
  by 
  

  

  