﻿Vegetable 
  Assimilation 
  and 
  Respiration. 
  

  

  253 
  

  

  until 
  it 
  reached 
  a 
  value, 
  in 
  some 
  cases, 
  almost 
  as 
  large 
  as 
  that 
  of 
  leaves 
  

   which 
  had 
  been 
  exposed 
  for 
  three 
  or 
  more 
  days, 
  and 
  had 
  attained 
  a 
  normal 
  

   green 
  colour. 
  Reference 
  to 
  Expt. 
  Ill 
  will 
  reveal 
  that 
  leaves, 
  which 
  on 
  the 
  

   hrst 
  day 
  showed 
  no 
  assimilation, 
  on 
  the 
  third 
  day 
  had 
  reached 
  a 
  value 
  of 
  10"4, 
  

   whilst 
  the 
  normal 
  leaves 
  of 
  Expts. 
  V 
  and 
  VI 
  under 
  similar 
  conditions 
  gave 
  

   a 
  value 
  of 
  12 
  units. 
  Yet 
  throughout 
  each 
  increasing 
  series 
  there 
  was 
  no 
  

   increase 
  in 
  greenness 
  of 
  the 
  material. 
  

  

  Moreover, 
  if 
  the 
  leaves 
  after 
  greening 
  are 
  kept 
  in 
  the 
  dark 
  for 
  three 
  days, 
  

   they 
  show 
  at 
  the 
  end 
  of 
  that 
  period 
  an 
  assimilatory 
  power 
  of 
  the 
  same 
  

   ■dimensions 
  as 
  that 
  of 
  similar 
  leaves, 
  which 
  have 
  been 
  exposed 
  to 
  light 
  in 
  the 
  

   apparatus 
  during 
  a 
  considerable 
  part 
  of 
  the 
  three 
  days. 
  For 
  example, 
  the 
  

   leaves 
  of 
  Expt. 
  IIIa 
  received 
  the 
  same 
  treatment 
  as 
  those 
  of 
  Expt. 
  Ill, 
  

   except 
  that 
  they 
  were 
  in 
  the 
  dark 
  whilst 
  the 
  latter 
  were 
  in 
  the 
  apparatus. 
  

   At 
  the 
  end 
  of 
  three 
  days, 
  however, 
  they 
  showed 
  an 
  assimilation 
  of 
  9"2 
  units 
  

   as 
  compared 
  with 
  the 
  10 
  - 
  4 
  of 
  Expt. 
  Ill 
  — 
  values 
  almost 
  the 
  same. 
  

  

  That 
  the 
  above 
  features 
  are 
  general 
  for 
  such 
  partially 
  greened 
  etiolated 
  

   leaves 
  is 
  borne 
  out 
  by 
  numerous 
  results 
  obtained 
  with 
  other 
  material. 
  

   Additional 
  evidence 
  from 
  Avena 
  and 
  Vicia 
  is 
  set 
  out 
  in 
  the 
  Appendix. 
  

  

  2 
  4 
  6 
  8 
  10 
  12 
  14 
  16 
  »8 
  2.0 
  

  

  D&ys 
  from 
  Sottmrj. 
  

  

  The 
  results 
  of 
  Expts. 
  I 
  and 
  II, 
  comparable 
  in 
  that 
  the 
  leaves 
  were 
  of 
  

   similar 
  tones 
  of 
  greenness, 
  are 
  presented 
  graphically 
  in 
  the 
  accompanying 
  

   figure, 
  where 
  the 
  abscissae 
  are 
  days 
  counted 
  from 
  sowing 
  and 
  the 
  ordinates 
  

   oxygen 
  output 
  in 
  c.cs. 
  per 
  grm. 
  dry-weight 
  per 
  hour. 
  The 
  value 
  for 
  the 
  

   fully 
  green 
  leaves 
  of 
  Expt. 
  VI 
  is 
  included 
  for 
  comparative 
  purposes. 
  

  

  Seeking 
  the 
  interpretation 
  of 
  these 
  phenomena 
  we 
  may 
  dispose 
  of 
  certain 
  

  

  