﻿1890.] 
  BOTANICAL 
  GAZETTE, 
  20 
  

  

  D 
  

  

  k 
  

  

  r 
  

  

  

  causes 
  bread 
  to 
  rise 
  has 
  been 
  questioned 
  somewhat, 
  some 
  

   still 
  claiming 
  that 
  it 
  does, 
  others 
  that 
  it 
  has 
  nothing 
  whatever 
  

   to 
  do 
  with 
  the 
  rising, 
  while 
  still 
  others 
  take 
  a 
  halfway 
  course, 
  

   that 
  is, 
  that 
  yeast 
  and 
  bacteria 
  acting 
  together 
  do 
  the 
  work. 
  

   Chicandard,^ 
  in 
  1883, 
  presented 
  a 
  paper 
  before 
  the 
  French 
  

   Academy 
  of 
  Sciences 
  in 
  which 
  he 
  explained 
  the 
  fermentation 
  

   of 
  bread 
  to 
  be 
  the 
  result, 
  not 
  of 
  yeast, 
  but 
  of 
  a 
  special 
  bacil- 
  

   lus 
  that 
  develops 
  normally 
  in 
  the 
  dough, 
  while 
  the 
  yeast 
  only 
  

   hastens 
  the 
  development- 
  He 
  claims 
  that 
  the 
  most 
  essential 
  

   part 
  of 
  the 
  fermentation 
  is 
  the 
  transformation 
  of 
  a 
  part 
  of 
  the 
  

   insoluble 
  albuminoids 
  into 
  soluble 
  ones. 
  

  

  Laurent,^ 
  writing 
  four 
  vears 
  later, 
  presents 
  the 
  same 
  idea 
  

   in 
  regard 
  to 
  the 
  cause 
  of 
  the 
  fermentation. 
  He 
  found 
  in 
  

   dough 
  a 
  bacterium, 
  Bacillus 
  panificans, 
  as 
  he 
  calls 
  it, 
  that 
  

   occurs 
  in 
  short 
  and 
  long 
  rods 
  and 
  forms 
  sharply 
  defined 
  yel- 
  

   low 
  colonies 
  on 
  plate-cultures. 
  It 
  can 
  stand 
  a 
  high 
  degree 
  

   of 
  heat, 
  so 
  high 
  that 
  the 
  rods 
  are 
  said 
  to 
  be 
  still 
  alive 
  under 
  

   the 
  crust 
  of 
  the 
  bread. 
  The 
  spores 
  w^ill 
  stand 
  long 
  heating 
  

   at 
  boiling 
  temperature. 
  Laurent 
  says 
  that 
  this 
  bacillus 
  is 
  

   responsible 
  for 
  the 
  formation 
  of 
  carbon-dioxide, 
  besides 
  a 
  

   certain 
  amount 
  of 
  lactic, 
  butyric 
  and 
  acetic 
  acids. 
  In 
  the 
  

   J^^arm 
  season 
  this 
  bacillus 
  sometimes 
  causes 
  the 
  bread 
  to 
  

   become 
  slimy, 
  so 
  that 
  it 
  can 
  be 
  drawn 
  out 
  into 
  threads. 
  In 
  

   such 
  bread 
  are 
  found 
  myriads 
  of 
  the 
  organisms 
  which 
  change 
  

   the 
  starch 
  into 
  ervthrodextrin, 
  and 
  thus 
  bring 
  about 
  the 
  slimy 
  

   nietamorphosis. 
  

  

  . 
  Wigand^ 
  agrees 
  in 
  substance 
  with 
  the 
  preceding 
  views 
  

   i?i^?^^^ 
  to 
  bread 
  fermentation, 
  but 
  he 
  says 
  that 
  the 
  bacillus 
  

  

  the 
  albumen 
  of 
  the 
  gluten, 
  for 
  

  

  IS 
  formed 
  spontaneously 
  from 
  

   although 
  an 
  eminent 
  scientist 
  

  

  h 
  K 
  r 
  -*^— 
  ^ 
  ov-ii^xiLi^L 
  and 
  writing 
  but 
  six 
  years 
  ago, 
  

  

  e 
  beheved 
  in 
  the 
  now 
  generally 
  discarded 
  theory 
  of 
  spon- 
  ' 
  

  

  taneous 
  generation. 
  

  

  fo 
  1 
  '^ 
  ^^stly, 
  Marcano*^ 
  believes 
  that 
  the 
  motile 
  bacteria 
  

   ^^ 
  m 
  dough 
  are 
  the 
  true 
  cause 
  of 
  the 
  fermentation. 
  

  

  j^j^.^l^P^sed 
  to 
  the 
  view 
  that 
  bacteria 
  are 
  the 
  cause 
  of 
  the 
  

   mg 
  of 
  bread, 
  we 
  have 
  the 
  opinions 
  of 
  such 
  men 
  as 
  Birn- 
  

  

  J^^^^^^:^^ 
  and 
  Diinnenberger. 
  Birnbaum'^ 
  thinks 
  that 
  

  

  J 
  ^ 
  icandard, 
  Comptes 
  rend. 
  1883, 
  p. 
  1585; 
  quoted 
  by 
  Dunaeuberger, 
  1. 
  c. 
  and 
  Peters 
  

  

  Belg 
  \^?^i.' 
  ^- 
  ^^^^- 
  ^cad. 
  Roy. 
  Sci. 
  Belg.» 
  Vol. 
  X, 
  1885, 
  p. 
  765; 
  BuU. 
  Soc. 
  Roy. 
  Bot. 
  

   ^' 
  Jusr 
  ^^'' 
  ^^' 
  " 
  ^' 
  ^^^ 
  ' 
  abstract 
  in 
  Centralb. 
  f. 
  Bak. 
  u. 
  Parasitenk., 
  Vol. 
  I, 
  1887, 
  p. 
  

  

  MViJnH 
  ^^^^^^^^^" 
  ^^^- 
  ^^^' 
  Pt. 
  1. 
  1886, 
  pp. 
  396, 
  397. 
  

  

  'Marca 
  ^^^^^^^^^ 
  ^^^^l 
  Fermentvvirkung 
  der 
  Bakterien. 
  2d 
  Ed., 
  1884, 
  p. 
  U. 
  

   ''Birnba^^' 
  ^^^^^' 
  ^^^^^y 
  xcvi, 
  xcvii, 
  1883; 
  quoted 
  by 
  Dunnenberger, 
  1. 
  c. 
  

   Mn. 
  ^^' 
  Lehrbuch 
  der 
  landwirtscbaftlichen 
  Gewerbe, 
  1866, 
  Vol- 
  1, 
  p. 
  228; 
  

  

  ^y 
  ^onenberger, 
  1. 
  c 
  

  

  quoted 
  

  

  