﻿FUNGI 
  AND 
  FUNGOUS 
  DISEASES 
  OF 
  PLANTS 
  235 
  

  

  undergrowth 
  one 
  may 
  find 
  large 
  numbers 
  of 
  these 
  saprophytic 
  

   plants 
  growing 
  upon 
  decaying 
  organic 
  matter. 
  By 
  breaking 
  

   open 
  an 
  old 
  log 
  or 
  branch 
  of 
  wood 
  (fig. 
  183) 
  upon 
  which 
  

   fungi 
  are 
  growing, 
  or 
  by 
  upturning 
  rich 
  soil, 
  one 
  often 
  finds 
  the 
  

   extensively 
  interwoven, 
  mold-like 
  saprophytic 
  growth. 
  This 
  

   internal 
  growth 
  gathers 
  nourish- 
  

   ing 
  material 
  for 
  the 
  whole 
  depend- 
  

   ent 
  plant, 
  and 
  at 
  the 
  same 
  time 
  

   helps 
  to 
  bring 
  about 
  the 
  decay 
  of 
  

   the 
  material 
  upon 
  which 
  it 
  lives. 
  

   221. 
  The 
  algae-fungi. 
  There 
  are 
  

   many 
  different 
  groups 
  of 
  fungi, 
  

   and 
  they 
  are 
  often 
  so 
  unlike 
  that 
  

   it 
  is 
  at 
  first 
  hard 
  for 
  the 
  student 
  

   to 
  regard 
  them 
  as 
  belonging 
  to 
  

   the 
  same 
  larger 
  group, 
  the 
  fungi. 
  

   In 
  the 
  case 
  of 
  some 
  of 
  the 
  molds, 
  

   if 
  the 
  thread-like 
  fibers 
  of 
  which 
  

   they 
  are 
  composed 
  were 
  to 
  pos- 
  

   sess 
  chlorophyll, 
  they 
  would 
  ap- 
  

   pear 
  quite 
  similar 
  to 
  some 
  of 
  the 
  

   algce. 
  Because 
  of 
  this 
  structural 
  

   resemblance 
  one 
  group 
  of 
  fungi 
  is 
  

   called 
  the 
  algse-fungi 
  (Phycomy- 
  

   cetes, 
  meaning 
  " 
  algae-fungi 
  "), 
  

   that 
  is, 
  fungi 
  that 
  are 
  more 
  like 
  

   algse 
  than 
  are 
  other 
  fungi. 
  Most 
  

   of 
  the 
  saprophytic 
  molds 
  and 
  a 
  

   good 
  many 
  destructive 
  parasites 
  belong 
  to 
  the 
  algae-fungi. 
  

   A 
  few 
  types 
  will 
  show 
  their 
  nature, 
  how 
  they 
  live, 
  and 
  how 
  

   they 
  affect 
  the 
  things 
  upon 
  which 
  they 
  live. 
  

  

  222. 
  Bread 
  mold. 
  If 
  a 
  piece 
  of 
  slightly 
  moistened 
  bread 
  is 
  

   placed 
  in 
  a 
  glass 
  jar 
  or 
  in 
  a 
  covered 
  dish 
  for 
  a 
  few 
  days, 
  an 
  abun- 
  

   dant 
  supply 
  of 
  mold 
  soon 
  appears 
  upon 
  it. 
  Several 
  kinds 
  of 
  

   molds 
  may 
  develop 
  at 
  the 
  same 
  time 
  under 
  such 
  conditions, 
  

   but 
  the 
  common 
  bread 
  mold, 
  or 
  black 
  mold, 
  is 
  the 
  one 
  which 
  

  

  FIG. 
  183. 
  A 
  section 
  through 
  a 
  

   dead 
  branch 
  of 
  a 
  cotton 
  wood 
  tree 
  

  

  Note 
  the 
  white 
  patches 
  of 
  internal 
  

   mycelium 
  and 
  the 
  external 
  spore- 
  

   producing 
  hodies 
  of 
  the 
  fungus, 
  a 
  

   Polyporus 
  

  

  