﻿1890.] 
  

  

  BOTANICAL 
  GAZETTE 
  

  

  257 
  

  

  M 
  

  

  Experiment 
  JVo. 
  i.—On 
  the 
  25th 
  of 
  April 
  a 
  potted 
  plant 
  

   of 
  Ampelopsis 
  quinquefolia, 
  which 
  had 
  been 
  in 
  the 
  green- 
  

   house 
  for 
  four 
  months, 
  was 
  removed 
  to 
  the 
  open 
  ground 
  and 
  

   planted 
  on 
  the 
  spot 
  where 
  the 
  diseased 
  berries 
  had 
  lain 
  all 
  

   winter. 
  The 
  vine, 
  which 
  was 
  about 
  two 
  feet 
  long, 
  was 
  spread 
  

   out 
  on 
  the 
  ground 
  and 
  a 
  large 
  number 
  of 
  grapes 
  containing 
  

   ascospores 
  were 
  placed 
  on 
  the 
  leaves. 
  For 
  the 
  next 
  twelve 
  

   days 
  there 
  were 
  frequent 
  rains, 
  which, 
  with 
  the 
  warm 
  weather 
  

   prevailing 
  at 
  the 
  time, 
  afforded 
  just 
  the 
  conditions 
  necessary 
  

   ^or 
  the 
  rapid 
  development 
  of 
  the 
  fungus. 
  On 
  the 
  loth 
  of 
  

   ay 
  a 
  number 
  of 
  the 
  Ampelopsis 
  leaves 
  showed 
  the 
  charac- 
  

   teristic 
  spots 
  of 
  the 
  Phyllosticta, 
  and 
  an 
  examination 
  of 
  these 
  

   a 
  few 
  days 
  later 
  revealed 
  the 
  presence 
  of 
  pycnidia 
  and 
  pyc- 
  

   nidia-spores. 
  The 
  spores 
  and 
  pjxnidia 
  did 
  not 
  differ 
  in 
  any 
  

   respect 
  from 
  those 
  formed 
  in 
  the 
  usual 
  way. 
  Another 
  plant 
  

   ot 
  Ampelopsis 
  quinquefolia 
  about 
  thirty 
  feet 
  distant 
  from 
  the 
  

   rst 
  served 
  as 
  a 
  control 
  experiment. 
  No 
  spots 
  appeared 
  on 
  

   this 
  plant 
  at 
  all. 
  

  

  Experiment 
  No. 
  2. 
  — 
  May 
  10 
  two 
  pot 
  grown 
  plants 
  of 
  

  

  ^Norton's 
  Virginia 
  grape 
  having 
  four 
  well 
  formed 
  leaves 
  were 
  

  

  P 
  anted 
  in 
  my 
  garden 
  and 
  were 
  immediately 
  covered 
  with 
  

  

  eli 
  jars. 
  May 
  11 
  the 
  bell 
  jars 
  were 
  removed 
  and 
  about 
  a- 
  

  

  andful 
  of 
  the 
  old 
  grapes 
  containing 
  ascospores 
  were 
  placed 
  

  

  op 
  the 
  leaves, 
  the 
  jars 
  being 
  immediately 
  replaced 
  and 
  not 
  

  

  la?t 
  i!^- 
  ^^'^^^ 
  ^o^ 
  a 
  month, 
  except 
  to 
  water 
  the 
  plants, 
  the 
  

   Jter 
  being 
  done 
  every 
  two 
  days. 
  At 
  the 
  expiration 
  of 
  

   ^^"^y-five 
  days 
  both 
  of 
  the 
  plants 
  treated 
  as 
  above 
  showed 
  

   number 
  of 
  leaf 
  spots, 
  which 
  upon 
  examination 
  proved 
  to 
  

   e 
  typical 
  Phyllosticta 
  discolorations 
  bearing 
  upon 
  their 
  sur- 
  

   ges 
  pycnidia, 
  which 
  contained 
  the 
  usual 
  shaped 
  spores. 
  A 
  

   hp^uu^^*^^^ 
  grapes 
  fifteen 
  feet 
  distant 
  remained 
  perfectly 
  

   eaithy 
  throughout 
  this 
  period. 
  

   £.xperimeut 
  No. 
  j.— 
  Two 
  plants 
  of 
  Muscat 
  of 
  Alexan- 
  

   iirs 
  ^^?F^ 
  growing 
  in 
  the 
  green-house 
  were 
  covered 
  with 
  bell 
  

   t'lin 
  .1 
  V^ 
  ^^y 
  ^° 
  several 
  bunches 
  of 
  diseased 
  berries 
  ob- 
  

   ^ver 
  1 
  °"^ 
  ^^^^ 
  s^"^e 
  source 
  as 
  in 
  the 
  preceding 
  experiments 
  

   lost- 
  f 
  on 
  the 
  leaves 
  of 
  each 
  plant. 
  In 
  ten 
  days 
  Phyl- 
  

  

  fivp 
  rl 
  ^^^^^ 
  ^^^^^ 
  showing 
  on 
  a 
  number 
  of 
  the 
  leaves, 
  and 
  

   bv 
  tl. 
  ?^ 
  ^ater 
  a 
  number 
  of 
  the 
  leaves 
  were 
  almost 
  destroyed 
  

   tend 
  ^"^"^- 
  ^^^ 
  leaves 
  of 
  the 
  Muscat, 
  being 
  thin 
  and 
  

   instP 
  ,1 
  ^^^^ 
  ^^ 
  succumb 
  very 
  readily 
  to 
  the 
  disease, 
  which 
  

   All 
  mh 
  .^'^^'T'ing 
  definite 
  spots 
  involves 
  the 
  whole 
  leaf, 
  

   tner 
  vines 
  in 
  the 
  same 
  house 
  remained 
  healthy. 
  

   ^^feriment 
  No. 
  ^.— 
  May 
  25 
  four 
  leaves 
  of 
  a 
  house 
  grown 
  

  

  