﻿FUNGI 
  AND 
  FUNGOUS 
  DISEASES 
  OF 
  PLANTS 
  237 
  

  

  Under 
  magnification 
  the 
  hyplue 
  may 
  be 
  seen 
  to 
  consist 
  of 
  

   heavy, 
  tubular 
  cell 
  walls, 
  in 
  which 
  the 
  granular 
  protoplasm 
  is 
  

   not 
  separated 
  into 
  distinct 
  cellular 
  divisions 
  by 
  transverse 
  

   walls, 
  as 
  it 
  is 
  in 
  most 
  of 
  the 
  algse. 
  

  

  Bread 
  mold 
  lives 
  upon 
  and 
  within 
  its 
  nutrient 
  substance 
  

   and 
  absorbs 
  food 
  material 
  directly 
  from 
  it. 
  Parts 
  that 
  are 
  in 
  

   contact 
  with 
  the 
  sub-stratum 
  do 
  the 
  work 
  of 
  food 
  absorption. 
  

   Food 
  is 
  carried 
  through 
  the 
  tubular 
  cells 
  to 
  the 
  parts 
  of 
  the 
  

   mycelium 
  that 
  are 
  above 
  the 
  food 
  material. 
  Since 
  nutrient 
  

   material 
  is 
  secured 
  in 
  ready 
  and 
  abundant 
  supplies, 
  the 
  growth 
  

   and 
  extension 
  of 
  the 
  mold 
  is 
  usually 
  quite 
  rapid. 
  

  

  224. 
  Effect 
  of 
  mold 
  upon 
  bread. 
  If 
  a 
  piece 
  of 
  bread 
  upon 
  

   which 
  mold 
  is 
  growing 
  vigorously 
  is 
  kept 
  moist, 
  much 
  of 
  the 
  

   bread 
  is 
  consumed 
  by 
  the 
  mold, 
  but 
  usually 
  the 
  mold 
  will 
  not 
  

   continue 
  to 
  grow 
  until 
  the 
  bread 
  is 
  completely 
  consumed. 
  

   Either 
  because 
  it 
  has 
  secured 
  all 
  the 
  food 
  it 
  can 
  extract 
  from 
  

   the 
  bread, 
  or 
  because 
  it 
  has 
  secreted 
  substances 
  that 
  prevent 
  

   its 
  further 
  growth, 
  or 
  because 
  it 
  is 
  unable 
  to 
  hold 
  its 
  own 
  

   with 
  other 
  organisms 
  (molds 
  and 
  bacteria), 
  the 
  bread 
  mold 
  

   after 
  a 
  time 
  ceases 
  to 
  grow. 
  Other 
  molds 
  and 
  bacteria 
  may 
  

   appear, 
  one 
  kind 
  following 
  another 
  for 
  weeks, 
  until 
  the 
  decay 
  

   of 
  the 
  bread 
  is 
  almost 
  or 
  quite 
  complete. 
  

  

  If 
  the 
  mold, 
  and 
  the 
  material 
  upon 
  which 
  it 
  grows, 
  is 
  kept 
  

   tightly 
  sealed, 
  growth 
  stops 
  before 
  all 
  the 
  food 
  material 
  is 
  

   used. 
  Molds 
  often 
  grow 
  for 
  a 
  time 
  in 
  jars 
  of 
  fruit, 
  forming 
  

   upon 
  the 
  top 
  of 
  the 
  fruit 
  a 
  coating 
  which 
  remains 
  until 
  the 
  

   jar 
  is 
  opened. 
  If 
  this 
  coating 
  is 
  removed 
  and 
  a 
  fresh 
  supply 
  

   of 
  air 
  is 
  admitted, 
  a 
  new 
  growth 
  soon 
  appears, 
  and 
  if 
  a 
  con- 
  

   stant 
  supply 
  of 
  air 
  is 
  maintained, 
  various 
  molds 
  may 
  grow 
  

   until 
  all 
  the 
  fruit 
  is 
  destroyed. 
  

  

  225. 
  Reproduction 
  of 
  bread 
  mold. 
  In 
  addition 
  to 
  vegetative 
  

   reproduction 
  by 
  means 
  of 
  stolons, 
  this 
  mold 
  also 
  reproduces 
  

   itself 
  both 
  asexually 
  and 
  sexually. 
  Upon 
  the 
  ends 
  of 
  upright 
  

   hyphae, 
  sporangia 
  are 
  produced 
  (fig. 
  184). 
  In 
  the 
  develop- 
  

   ment 
  of 
  the 
  sporangia, 
  first 
  a 
  transverse 
  wall 
  cuts 
  off 
  a 
  small 
  

   tip 
  of 
  the 
  upright 
  stalk. 
  This 
  tip 
  cell 
  grows 
  rapidly 
  until 
  it 
  

  

  