﻿FUNGI 
  AND 
  FUNGOUS 
  DISEASES 
  OF 
  PLANTS 
  251 
  

  

  Reindeer 
  moss 
  {Cladonia 
  rangiferina) 
  is 
  eaten 
  in 
  winter 
  by 
  

   animals, 
  which 
  find 
  it 
  green 
  and 
  nutritious 
  when 
  they 
  remove 
  

   the 
  snow 
  from 
  above 
  it. 
  A 
  few 
  lichens 
  are 
  used 
  as 
  food 
  for 
  

   men, 
  though 
  they 
  are 
  not 
  especially 
  nutritious. 
  A 
  mucilagi- 
  

   nous 
  and 
  starchy 
  food 
  is 
  prepared 
  from 
  Cetraria 
  islandica, 
  a 
  

   lichen 
  which 
  is 
  known 
  

   as 
  Iceland 
  moss. 
  In 
  

   Sweden 
  Sticta 
  pul- 
  

   monacea, 
  a 
  very 
  bitter 
  

   lichen, 
  is 
  sometimes 
  

   used 
  as 
  a 
  substitute 
  

   for 
  hops 
  in 
  processes 
  

   of 
  brewing. 
  Various 
  

   dyes 
  are 
  prepared 
  from 
  

   lichens 
  and 
  are 
  known 
  

   in 
  the 
  markets 
  as 
  orchil 
  

   and 
  cudbear, 
  but 
  these 
  

   are 
  not 
  so 
  commonly 
  

   used 
  as 
  formerly. 
  Lit- 
  

   mus, 
  used 
  in 
  preparing 
  

   litmus, 
  or 
  blue-test 
  

   paper 
  as 
  a 
  test 
  for 
  the 
  

   presence 
  of 
  acids, 
  is 
  

   also 
  prepared 
  from 
  

   lichens. 
  

  

  238. 
  The 
  basidium, 
  

   or 
  stalk 
  fungi. 
  The 
  sac 
  

   fungi 
  were 
  so 
  named 
  

   because 
  the 
  spores 
  are 
  

   formed 
  in 
  a 
  sac. 
  In 
  like 
  manner 
  the 
  basidium, 
  or 
  stalk, 
  fungi 
  

   (Basidiomycetes) 
  are 
  so 
  called 
  because 
  the 
  spores 
  are 
  formed 
  

   on 
  the 
  outside 
  of 
  the 
  tip 
  of 
  a 
  hypha 
  known 
  as 
  the 
  stalk, 
  or 
  

   basidium. 
  Within 
  this 
  division 
  of 
  fungi 
  several 
  sub-divisions 
  

   are 
  recognized. 
  One 
  of 
  these, 
  the 
  smuts, 
  is 
  represented 
  by 
  

   forms 
  that 
  frequently 
  appear 
  upon 
  the 
  ears 
  of 
  corn 
  (fig. 
  196) 
  

   and 
  upon 
  heads 
  of 
  oats 
  (fig, 
  197), 
  wheat, 
  barley, 
  and 
  other 
  

  

  FIG. 
  196. 
  Corn 
  smut 
  

  

  An 
  ear 
  of 
  corn, 
  part 
  of 
  which 
  has 
  been 
  destroyed 
  

  

  and 
  replaced 
  by 
  a 
  mass 
  of 
  smut 
  spores. 
  Photograph 
  

  

  by 
  Kern, 
  Pennsylvania 
  State 
  College 
  

  

  