﻿FUNGI 
  AND 
  FUNGOUS 
  DISEASES 
  OF 
  PLANTS 
  247 
  

  

  are 
  enlarged, 
  and 
  at 
  the 
  same 
  time 
  the 
  alcohol 
  is 
  evaporated. 
  

   By 
  former 
  methods 
  of 
  bread-making 
  pure 
  cultures 
  of 
  yeast 
  

   were 
  less 
  likely 
  to 
  be 
  secured, 
  wild 
  yeasts 
  very 
  frequently 
  ap- 
  

   pearing. 
  By 
  modern 
  methods, 
  quite 
  similar 
  to 
  those 
  used 
  in 
  

   bacteriology, 
  pure 
  cultures 
  may 
  be 
  obtained, 
  and 
  it 
  is 
  there- 
  

   fore 
  possible 
  to 
  secure 
  the 
  exact 
  kind 
  of 
  fermentation 
  of 
  the 
  

   dough 
  that 
  is 
  desired. 
  1 
  

  

  The 
  processes 
  of 
  fermentation 
  by 
  yeasts 
  are 
  used 
  in 
  the 
  

   manufacture 
  of 
  alcohol, 
  wine, 
  beer, 
  and 
  other 
  liquors 
  which 
  

   contain 
  alcohol. 
  Certain 
  definite 
  kinds 
  of 
  yeast 
  produce 
  cer- 
  

   tain 
  kinds 
  of 
  alcoholic 
  fermentation, 
  and 
  it 
  is 
  necessary 
  for 
  the 
  

   brewer 
  to 
  keep 
  pure 
  cultures 
  of 
  the 
  desired 
  yeasts 
  in 
  order 
  to 
  

   insure 
  the 
  particular 
  quality 
  of 
  his 
  product. 
  In 
  1856 
  the 
  great 
  

   French 
  scientist, 
  Louis 
  Pasteur, 
  succeeded 
  in 
  devising 
  methods 
  

   of 
  pure 
  culture 
  by 
  isolating 
  single 
  yeast 
  plants 
  and 
  growing 
  

   a 
  colony 
  from 
  each. 
  Thus 
  the 
  particular 
  result 
  to 
  be 
  secured 
  

   could 
  be 
  determined 
  by 
  the 
  kind 
  of 
  yeast 
  selected 
  for 
  use 
  in 
  

   fermentation. 
  It 
  was 
  this 
  method 
  of 
  pure 
  culture 
  which 
  opened 
  

   the 
  way 
  for 
  many 
  of 
  the 
  modern 
  bacteriological 
  investigations. 
  2 
  

  

  235. 
  The 
  lichens. 
  This 
  is 
  a 
  group 
  of 
  plants 
  of 
  peculiar 
  

   habits 
  and 
  structures. 
  Often 
  members 
  of 
  the 
  group 
  may 
  be 
  

   seen 
  adhering 
  closely 
  to 
  the 
  bark 
  of 
  trees 
  (fig. 
  193) 
  or 
  to 
  the 
  

   surface 
  of 
  rocks. 
  They 
  also 
  appear 
  upon 
  the 
  soil 
  in 
  great 
  

   abundance. 
  Sometimes 
  they 
  hang 
  from 
  branches 
  of 
  trees 
  in 
  

   ragged 
  gray 
  masses 
  (fig. 
  194) 
  that 
  look 
  somewhat 
  like 
  the 
  

   common 
  Southern 
  hanging 
  seed 
  plant 
  known 
  as 
  Florida 
  moss. 
  

  

  1 
  An 
  especially 
  interesting 
  paper 
  is 
  " 
  Bread 
  and 
  the 
  Principles 
  of 
  Bread 
  

   Making," 
  by 
  Helen 
  W. 
  Atwater, 
  Farmers' 
  Bulletin 
  112, 
  U.S. 
  Dept. 
  Agr., 
  

   1910. 
  

  

  2 
  TLe 
  following 
  citations 
  will 
  indicate 
  a 
  few 
  of 
  the 
  many 
  plant 
  diseases 
  

   that 
  are 
  caused 
  by 
  sac 
  fungi. 
  

  

  " 
  Root 
  Rot 
  of 
  Tobacco," 
  Annual 
  Report, 
  Conn. 
  Agr. 
  Exp. 
  Sta., 
  1906. 
  

  

  "Peach 
  Mildew," 
  Bulletin 
  107, 
  Colo. 
  Agr. 
  Exp. 
  Sta., 
  1906. 
  

  

  "Wilt 
  Disease 
  of 
  Cotton, 
  Watermelon, 
  and 
  Cowpea," 
  Bulletin 
  17, 
  Divi- 
  

   sion 
  of 
  Vegetable 
  Pathology, 
  U.S. 
  Dept. 
  Agr., 
  1899. 
  

  

  "Black 
  Knot," 
  Bulletin 
  81, 
  Cornell 
  University 
  Agr. 
  Exp. 
  Sta., 
  1894. 
  

  

  "The 
  Bitter 
  Rot 
  of 
  Apples," 
  Bulletin 
  44, 
  Bureau 
  of 
  Plant 
  Industry, 
  

   U.S. 
  Dept. 
  Agr., 
  1903. 
  

  

  