﻿Branner 
  — 
  Bacteria 
  and 
  the 
  Decomposition 
  of 
  Bocks. 
  439 
  

  

  in 
  decayed 
  rocks, 
  let 
  us 
  inquire 
  into 
  the 
  possibility 
  of 
  their 
  

   finding 
  conditions 
  favorable 
  to 
  their 
  existence 
  in 
  undecayed 
  

   ones. 
  

  

  There 
  is 
  a 
  great 
  difference 
  among 
  bacteria 
  with 
  regard 
  to 
  

   the 
  conditions 
  uuder 
  which 
  they 
  thrive. 
  For 
  example, 
  those 
  

   called 
  cerobiotic 
  by 
  Pasteur 
  require 
  a 
  large 
  supply 
  of 
  free 
  oxy- 
  

   gen, 
  while 
  the 
  ancerobiotic 
  thrive 
  best 
  when 
  the 
  oxygen 
  is 
  kept 
  

   from 
  them. 
  

  

  The 
  kind 
  found 
  by 
  Muntz 
  in 
  decayed 
  rocks 
  are 
  what 
  are 
  

   known 
  as 
  nitrifying 
  bacteria, 
  that 
  is 
  bacteria 
  that 
  reduce 
  nitro- 
  

   genous 
  matter 
  to 
  nitric 
  acid, 
  or 
  nitric 
  acid 
  to 
  lower 
  forms 
  of 
  

   oxidation. 
  To 
  most 
  forms 
  organic 
  food 
  is 
  absolutely 
  indis- 
  

   pensable, 
  but 
  several 
  authorities 
  have 
  demonstrated 
  that 
  the 
  

   nitrifying 
  bacteria 
  may 
  live 
  without 
  organic 
  food.* 
  This 
  fact 
  

   seems 
  at 
  first 
  to 
  place 
  the 
  statement 
  of 
  Muntz 
  beyond 
  ques- 
  

   tion, 
  for 
  if 
  bacteria 
  can 
  live 
  in 
  inorganic 
  media, 
  why 
  can 
  they 
  

   not 
  live 
  in 
  the 
  rocks 
  '? 
  But 
  these 
  bacteria 
  are 
  composed 
  princi- 
  

   pally 
  of 
  carbon 
  and 
  nitrogen 
  and 
  in 
  order 
  to 
  live 
  they 
  must 
  

   take 
  up 
  these 
  substances 
  with 
  their 
  nourishment, 
  either 
  from 
  

   the 
  air 
  or 
  from 
  some 
  other 
  source. 
  It 
  is 
  known 
  that 
  the 
  carbon 
  

   of 
  the 
  bacteria 
  may 
  be 
  derived 
  from 
  organic 
  sources. 
  De 
  Bary 
  

   says 
  that 
  " 
  as 
  far 
  as 
  we 
  fully 
  and 
  certainly 
  know, 
  the 
  parasitic 
  

   mode 
  of 
  life 
  is 
  always 
  indispensable 
  to 
  the 
  complete 
  develop- 
  

   ment 
  of 
  the 
  facultative 
  saprophytes" 
  which 
  is 
  understood 
  to 
  

   mean 
  that 
  organic 
  matter 
  is 
  necessary 
  to 
  that 
  existence. 
  f 
  

  

  Warming, 
  a 
  thoroughly 
  trustworthy 
  authority, 
  definitely 
  

   states 
  that 
  " 
  organic 
  carbon 
  compounds 
  are 
  indispensable 
  for 
  all 
  

   bacteria 
  (except, 
  as 
  it 
  appears, 
  for 
  the 
  nitrifying 
  organisms), 
  as 
  

   they 
  can 
  only 
  obtain 
  the 
  necessary 
  supplies 
  of 
  carbon 
  from 
  this 
  

   source.";}: 
  Note 
  his 
  exception. 
  He 
  also 
  says 
  that 
  " 
  the 
  bac- 
  

   teria 
  are 
  unable 
  to 
  assimilate 
  carbon 
  from 
  the 
  carbonic 
  acid 
  of 
  

   the 
  air." 
  Berthelot 
  says 
  that 
  the 
  carbon 
  and 
  hydrogen 
  of 
  the 
  

   atmosphere 
  does 
  not 
  appear 
  to 
  be 
  capable 
  of 
  supporting 
  the 
  

   life 
  of 
  the 
  nitrogen-fixing 
  bacteria, 
  and 
  that 
  they 
  are 
  nourished 
  

   by 
  substances 
  furnished 
  by 
  higher 
  organisms.§ 
  

  

  Experiments 
  by 
  Monro 
  in 
  1886, 
  || 
  by 
  Frankland 
  in 
  1885-6 
  

   and 
  by 
  Winogradsky 
  in 
  I890^[ 
  have 
  demonstrated 
  that 
  bacteria 
  

   of 
  more 
  than 
  one 
  kind 
  can 
  be 
  propagated 
  in 
  inorganic 
  media. 
  

   These 
  media, 
  however, 
  of 
  a 
  necessity 
  contained 
  carbon 
  and 
  

  

  *Phil. 
  Trans. 
  Roy. 
  Soc, 
  1590, 
  B.107; 
  Nature, 
  xlvi. 
  1392, 
  136-138; 
  Annales 
  

   de 
  l'lnstitut 
  Pasteur, 
  1890, 
  268; 
  Exper. 
  Station 
  Bull. 
  8 
  U. 
  S. 
  Dept. 
  of 
  Agriculture, 
  

   1892, 
  42 
  et 
  seq 
  ; 
  Comptes 
  Rendus, 
  1S93, 
  cxvi, 
  842-84 
  9. 
  

  

  f 
  Comparative 
  morphology 
  and 
  biology 
  of 
  the 
  fungi, 
  mycetozoa. 
  and 
  bacteria, 
  

   by 
  A. 
  de 
  Bary; 
  revised 
  by 
  Isaac 
  B. 
  Balfour. 
  Oxford, 
  1887, 
  356. 
  

  

  % 
  A 
  handbook 
  of 
  systematic 
  botany, 
  by 
  Dr. 
  E. 
  Warming. 
  Translated 
  by 
  M. 
  C. 
  

   Potter, 
  London, 
  1895, 
  31-32. 
  

  

  § 
  Nature, 
  May 
  4, 
  1893, 
  xlviii, 
  23 
  ; 
  Compt. 
  Rend, 
  1893, 
  842, 
  for 
  April 
  21. 
  

  

  || 
  Jour. 
  Chem. 
  Soc, 
  1886, 
  651. 
  

  

  IT 
  Annales 
  de 
  l'lnstitut 
  Pasteur, 
  1890, 
  268. 
  

  

  