﻿Organisms 
  and 
  Nucleic 
  Acid 
  Derivatives 
  on 
  Plant 
  Growth. 
  91. 
  

  

  Effect 
  of 
  Bacillus 
  radicicola. 
  

  

  A 
  further 
  experiment 
  was 
  started 
  in 
  September, 
  1917, 
  to 
  test 
  the 
  effect 
  of 
  

   the 
  nitrogen-fixing 
  organism 
  of 
  leguminous 
  nodules 
  — 
  Bacillus 
  radicicola 
  — 
  and 
  

   to 
  compare 
  it 
  with 
  that 
  of 
  Azotobacter 
  chroococcum. 
  The 
  rate 
  of 
  growth 
  and 
  

   multiplication 
  was 
  necessarily 
  slow 
  in 
  this 
  advanced 
  season 
  of 
  the 
  year, 
  and 
  

   therefore 
  the 
  margin 
  for 
  experimental 
  error 
  became 
  greater, 
  but 
  in 
  spite 
  of 
  

   these 
  objections 
  fairly 
  uniform 
  results 
  were 
  obtained. 
  

  

  Fifteen 
  dishes 
  were 
  arranged 
  in 
  three 
  series 
  of 
  five 
  dishes 
  each. 
  All 
  con- 
  

   tained 
  150 
  c.c. 
  of 
  Detmer's 
  solution, 
  and 
  the 
  following 
  additions 
  were 
  

   made 
  : 
  — 
  Series 
  II, 
  1 
  grm. 
  of 
  autoclaved 
  Azotobacter 
  chroococcum 
  per 
  1000 
  c.c, 
  

   and 
  Series 
  III, 
  1 
  grm. 
  per 
  1000 
  c.c. 
  of 
  autoclaved 
  Bacillus 
  radicicola, 
  grown 
  in 
  

   the 
  same 
  manner 
  on 
  maltose-agar 
  plates. 
  

  

  Table 
  IV. 
  

  

  Series. 
  

  

  

  1st 
  

  

  '2nd 
  

  

  3rd 
  

  

  4th 
  

  

  5th 
  

  

  6th 
  

  

  7th 
  

  

  8th 
  

  

  No. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  week. 
  

  

  I. 
  

  

  f 
  

   1 
  

  

  1 
  

  

  19 
  

  

  42 
  

  

  80 
  

  

  100 
  

  

  120 
  

  

  160 
  

  

  176 
  

  

  216 
  

  

  

  2 
  

  

  21 
  

  

  50 
  

  

  104 
  

  

  140 
  

  

  144 
  

  

  160 
  

  

  200 
  

  

  224 
  

  

  Detmer's 
  Solution 
  

  

  

  3 
  

  

  21 
  

  

  43 
  

  

  88 
  

  

  108 
  

  

  136 
  

  

  200 
  

  

  224 
  

  

  240 
  

  

  

  1 
  

  

  4 
  

  

  20 
  

  

  42 
  

  

  92 
  

  

  124 
  

  

  168 
  

  

  184 
  

  

  192 
  

  

  240 
  

  

  

  I 
  

  

  5 
  

  

  21 
  

  

  51 
  

  

  108 
  

  

  132 
  

  

  160 
  

  

  224 
  

  

  208 
  

  

  248 
  

  

  Mean 
  

  

  

  

  20 
  -4 
  

  

  45 
  -6 
  

  

  94 
  -4 
  

  

  120-8 
  

  

  145 
  6 
  

  

  185 
  -6 
  

  

  200 
  -0 
  

  

  233 
  -6 
  

  

  II. 
  

  

  

  

  

  

  

  

  

  

  

  

  

  r 
  

  

  6 
  

  

  24 
  

  

  57 
  

  

  130 
  

  

  196 
  

  

  276 
  

  

  420 
  

  

  556 
  

  

  732 
  

  

  Detmer's 
  Solution 
  

  

  7 
  

  

  22 
  

  

  57 
  

  

  116 
  

  

  176 
  

  

  232 
  

  

  404 
  

  

  548 
  

  

  672 
  

  

  + 
  

  

  

  8 
  

  

  21 
  

  

  50 
  

  

  118 
  

  

  184 
  

  

  264 
  

  

  416 
  

  

  512 
  

  

  664 
  

  

  Azotobacter 
  

  

  9 
  

  

  20 
  

  

  50 
  

  

  110 
  

  

  172 
  

  

  232 
  

  

  392 
  

  

  500 
  

  

  664 
  

  

  

  1 
  

  

  10 
  

  

  24 
  

  

  59 
  

  

  122 
  

  

  192 
  

  

  276 
  

  

  424 
  

  

  596 
  

  

  740 
  

  

  Mean 
  

  

  

  

  22-2 
  

  

  54 
  -6 
  

  

  119-2 
  

  

  184 
  -0 
  

  

  256 
  -0 
  

  

  411 
  -2 
  

  

  542 
  -4 
  

  

  694-4 
  

  

  III. 
  

  

  

  

  

  

  

  

  

  

  

  

  

  r 
  

   i 
  

  

  11 
  

  

  22 
  

  

  50 
  

  

  124 
  

  

  196 
  

  

  296 
  

  

  484 
  

  

  676 
  

  

  852 
  

  

  Detmer's 
  Solution 
  

  

  12 
  

  

  21 
  

  

  46 
  

  

  104 
  

  

  172 
  

  

  248 
  

  

  412 
  

  

  628 
  

  

  844 
  

  

  + 
  

  

  < 
  

  

  13 
  

  

  22 
  

  

  58 
  

  

  128 
  

  

  196 
  

  

  280 
  

  

  424 
  

  

  616 
  

  

  872 
  

  

  Bacillus 
  radicicola 
  

  

  i 
  

  

  14 
  

  

  23 
  

  

  57 
  

  

  124 
  

  

  200 
  

  

  288 
  

  

  520 
  

  

  696 
  

  

  928 
  

  

  

  I 
  

  

  15 
  

  

  26 
  

  

  59 
  

  

  128 
  

  

  200 
  

  

  280 
  

  

  464 
  

  

  624 
  

  

  832 
  

  

  Mean 
  

  

  

  

  22 
  -8 
  

  

  54-0 
  

  

  121 
  -6 
  

  

  192-8 
  

  

  278 
  "4 
  

  

  460 
  -8 
  

  

  648 
  -0 
  

  

  865-6 
  

  

  Ten 
  similar 
  Lemna 
  plants 
  were 
  counted 
  out 
  into 
  each 
  dish, 
  and 
  300 
  also 
  

   thoroughly 
  washed 
  for 
  an 
  estimation 
  of 
  their 
  dry 
  weight. 
  The 
  dishes 
  were 
  

  

  