﻿1 
  890. 
  J 
  BOTANICAL 
  GAZETTE. 
  

  

  13 
  

  

  thus 
  formed. 
  These 
  are 
  the 
  sterigmata, 
  and 
  on 
  each 
  of 
  

   these 
  a 
  gonidium 
  is 
  formed 
  (fig. 
  3). 
  There 
  are 
  seldom 
  

   fewer 
  than 
  four 
  gonidia 
  in 
  a 
  head, 
  and 
  they 
  usually 
  bear 
  a 
  

   much 
  larger 
  number. 
  With 
  perhaps 
  thirty 
  of 
  these 
  heads 
  

   to 
  the 
  sq. 
  mm., 
  which 
  is 
  about 
  the 
  average 
  number 
  on 
  an 
  

   ordinary 
  diseased 
  leaf, 
  it 
  is 
  not 
  strange 
  that, 
  under 
  favorable 
  

   conditions, 
  the 
  disease 
  should 
  spread 
  from 
  leaf 
  to 
  leaf 
  and 
  

   from 
  plant 
  to 
  plant, 
  with 
  surprising 
  rapidity. 
  If 
  the 
  growth 
  

   of 
  the 
  fungus 
  is 
  unchecked, 
  the 
  erect 
  hypha; 
  may 
  bud 
  out 
  

   just 
  below 
  the 
  gonidiophores, 
  and 
  after 
  growing 
  a 
  short 
  dis- 
  

   tance 
  produce 
  another 
  bunch 
  of 
  gonidia, 
  and 
  so 
  on, 
  thus 
  

   forming 
  a 
  series 
  such 
  as 
  is 
  shown 
  in 
  fig. 
  4. 
  

  

  In 
  this 
  disease 
  the 
  fungus 
  does 
  not 
  grow 
  in 
  the 
  sound 
  tis- 
  

   sues 
  of 
  the 
  host, 
  extracting 
  nourishment 
  from 
  them, 
  but 
  the 
  

   spores, 
  germinating 
  upon 
  the 
  surface 
  of 
  the 
  leaf, 
  in 
  some 
  way 
  

   macerate 
  it. 
  According 
  to 
  Marshall 
  Ward, 
  this 
  is 
  done 
  by 
  

   means 
  of 
  a 
  ferment 
  secreted 
  by 
  the 
  tips 
  of 
  the 
  hyphai. 
  I 
  

   have 
  not 
  as 
  yet 
  been 
  able 
  to 
  experiment 
  upon 
  this 
  ferment, 
  

   but 
  I 
  have 
  seen 
  nothing 
  to 
  invalidate 
  his 
  view. 
  The 
  cell 
  

   walls 
  having 
  been 
  softened, 
  the 
  hyphae 
  pass 
  through 
  them, 
  

   ramifying 
  amongst 
  the 
  decaying 
  tissues 
  of 
  the 
  leaf. 
  

  

  The 
  principal 
  conclusions 
  arrived 
  at 
  in 
  this 
  paper 
  are 
  the 
  

   followinjj 
  : 
  

  

  1. 
  A 
  disease, 
  hitherto 
  unexplained, 
  and 
  threatening 
  to 
  

   become 
  a 
  serious 
  epidemic 
  in 
  the 
  lily 
  fields 
  of 
  Bermuda, 
  has 
  

   been 
  assigned 
  to 
  a 
  definite 
  cause. 
  

  

  2. 
  There 
  is 
  no 
  evidence 
  that 
  the 
  blight 
  is 
  due 
  to 
  the 
  stings 
  

   of 
  insects. 
  

  

  3. 
  There 
  is 
  no 
  evidence 
  that 
  the 
  disease 
  is 
  caused 
  by 
  

   bacteria. 
  

  

  4. 
  There 
  is 
  strong 
  evidence 
  that 
  the 
  disease 
  is 
  caused 
  by 
  

   a 
  fungus, 
  growing 
  upon 
  and 
  within 
  the 
  leaves 
  or 
  flowers. 
  

  

  5. 
  The 
  fungus 
  which 
  causes 
  the 
  Bermuda 
  lil}' 
  disease 
  is 
  

   identical 
  with 
  the 
  Botrytis 
  recently 
  described 
  as 
  the 
  cause 
  of 
  

   a 
  similar 
  disease 
  in 
  England. 
  

  

  In 
  making 
  the 
  investigation 
  just 
  described 
  it 
  was 
  hoped 
  

   not 
  only 
  to 
  discover 
  the 
  cause 
  of 
  the 
  disease, 
  but 
  also 
  to 
  sug- 
  

   gest 
  remedial 
  measures. 
  In 
  this 
  connection 
  I 
  may 
  remark 
  

   that 
  the 
  fungus 
  itself 
  seems 
  to 
  be 
  delicate, 
  so 
  that 
  its 
  grow^th 
  

   might 
  probably 
  be 
  checked 
  by 
  almost 
  any 
  of 
  the 
  poisons 
  used 
  

   in 
  the 
  treatment 
  of 
  plant 
  diseases, 
  were 
  it 
  not 
  for 
  the 
  diffi- 
  

   culty 
  of 
  applying 
  these 
  effectively. 
  Either 
  a 
  pow^der 
  sprink- 
  

  

  