﻿FUNGI 
  AND 
  FUNGOUS 
  DISEASES 
  OF 
  PLANTS 
  245 
  

  

  CL 
  

  

  growths 
  of 
  the 
  mildew. 
  Another 
  complex 
  method 
  of 
  reproduc- 
  

   tion 
  results 
  in 
  forming 
  a 
  heavy-walled 
  body, 
  the 
  ascocarp, 
  so 
  

   called 
  because 
  it 
  is 
  the 
  body 
  which 
  contains 
  the 
  sacs 
  and 
  asco- 
  

   spores 
  (fig. 
  190). 
  In 
  late 
  summer 
  the 
  ascocarps 
  may, 
  without 
  

   magnification, 
  be 
  seen 
  as 
  small 
  black 
  bodies 
  upon 
  the 
  surface 
  

   of 
  lilac 
  leaves. 
  When 
  the 
  ascocarp 
  is 
  broken, 
  the 
  sacs 
  and 
  

   spores 
  are 
  exposed. 
  From 
  the 
  walls 
  of 
  the 
  ascocarp 
  peculiar 
  

   arms 
  extend, 
  and 
  in 
  the 
  lilac 
  mildew 
  and 
  some 
  related 
  mildews 
  

   these 
  have 
  strikingly 
  branched 
  tips. 
  

  

  The 
  heavy-walled 
  ascocarp 
  is 
  resistant 
  

   to 
  unfavorable 
  climatic 
  conditions. 
  It 
  

   may 
  pass 
  through 
  the 
  winter 
  and 
  break 
  

   open 
  in 
  the 
  following 
  spring, 
  thus 
  free- 
  

   ing 
  the 
  thin-walled 
  sacs. 
  Upon 
  escaping 
  

   from 
  the 
  sacs 
  the 
  spores 
  may 
  be 
  blown 
  

   or 
  carried 
  about 
  and 
  germinate 
  upon 
  

   new 
  host 
  leaves. 
  

  

  233. 
  Blue 
  mold 
  or 
  green 
  mold. 
  When 
  

   old 
  shoes, 
  gloves, 
  or 
  other 
  articles 
  made 
  

   of 
  leather 
  are 
  left 
  in 
  damp, 
  warm 
  places, 
  

   a 
  blue 
  or 
  green 
  mold 
  (Penicillium) 
  fre- 
  

   quently 
  develops 
  upon 
  them. 
  This 
  mold 
  

   also 
  grows 
  upon 
  old 
  lemons 
  and 
  oranges, 
  

   and 
  upon 
  cheese. 
  Various 
  species 
  have 
  

   distinctive 
  shades 
  of 
  color, 
  so 
  that 
  the 
  

   common 
  names 
  of 
  blue 
  mold 
  or 
  green 
  

   mold 
  can 
  be 
  taken 
  only 
  as 
  applying 
  in 
  a 
  general 
  way. 
  Certain 
  

   species 
  of 
  Penicillium 
  are 
  said 
  to 
  give 
  characteristic 
  flavors 
  to 
  

   the 
  cheese 
  in 
  which 
  they 
  grow, 
  as 
  Penicillium 
  Rogueforti 
  of 
  

   Roquefort 
  cheese 
  and 
  Penicillium 
  Camemberti 
  of 
  Camembert 
  

   cheese. 
  These 
  species 
  are 
  widely 
  distributed 
  and 
  are 
  found 
  

   growing 
  upon 
  many 
  substances 
  besides 
  cheese. 
  1 
  Penicillium 
  

  

  1 
  An 
  interesting 
  discussion 
  of 
  various 
  species 
  and 
  their 
  cultural 
  reactions 
  

   is 
  "Cultural 
  Studies 
  of 
  Species 
  of 
  Penicillium,'''' 
  by 
  Charles 
  Thorn, 
  Ph.D., 
  

   Mycologist 
  in 
  Cheese 
  Investigations, 
  Bulletin 
  148, 
  Bureau 
  of 
  Animal 
  Indus- 
  

   try, 
  U.S. 
  Dept. 
  Agr., 
  1910. 
  

  

  FIG. 
  191. 
  The 
  blue 
  mold 
  

  

  At 
  the 
  left 
  is 
  the 
  tip 
  of 
  a 
  

   hypha, 
  with 
  the 
  character- 
  

   istic 
  branches, 
  on 
  the 
  ends 
  

   of 
  which 
  are 
  the 
  spores 
  ; 
  at 
  

   the 
  right 
  are 
  germinating 
  

   spores. 
  Much 
  magnified. 
  

   After 
  Thorn 
  

  

  