﻿506 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  The 
  result 
  for 
  Vallisneria 
  is 
  just 
  what 
  was 
  expected, 
  but 
  in 
  the 
  case 
  

   of 
  Chara 
  it 
  was 
  thought 
  that 
  since 
  it 
  is 
  of 
  more 
  frequent 
  occurrence 
  

  

  in 
  the 
  sandy 
  soil, 
  perhaps 
  it 
  would 
  

   make 
  a 
  better 
  growth 
  in 
  No. 
  2 
  than 
  

   in 
  No. 
  1. 
  It 
  is 
  quite 
  possible 
  that 
  

   this 
  plant 
  is 
  unable 
  to 
  hold 
  posses- 
  

   sion 
  o*^ 
  the 
  soil 
  of 
  its 
  choice 
  because 
  

   of 
  the 
  interference 
  from 
  other 
  species. 
  

   It 
  does 
  occur 
  infrequently 
  along 
  with 
  

   Yallisneria 
  in 
  the 
  loam}^ 
  soil, 
  making- 
  

   excellent 
  growth 
  there, 
  and 
  since 
  ex- 
  

   periment 
  shows 
  this 
  soil 
  to 
  be 
  more 
  

   favorable 
  than 
  that 
  in 
  which 
  it 
  fre- 
  

   quently 
  occurs, 
  we 
  might 
  suppose 
  that 
  

   it 
  is 
  crowded 
  out 
  from 
  places 
  other- 
  

   wise 
  suitable 
  for 
  it. 
  

  

  Looking 
  to 
  the 
  mechanical 
  analy- 
  

   sis 
  as 
  shown 
  above 
  for 
  explanation 
  

   of 
  these 
  results, 
  it 
  is 
  difficult 
  to 
  find 
  

   differences 
  indicating 
  those 
  proper 
  

   ties 
  which 
  are 
  determining 
  factors 
  in 
  

   the 
  amount 
  of 
  growth 
  a 
  given 
  soil 
  

   will 
  sustain. 
  A 
  chemical 
  anal3^sis 
  also 
  is 
  probably 
  necessary. 
  

  

  Fig. 
  A..— 
  VaRim,eri(i 
  spiralis 
  after 
  6^ 
  weeks' 
  

   growth 
  in 
  sandy 
  soil 
  (No. 
  2) 
  . 
  

  

  GROWTH 
  IN 
  NUTRIENT 
  SOLUTIONS. 
  

  

  Having 
  established 
  the 
  fact 
  that 
  certain 
  aquatics 
  do 
  not 
  make 
  an 
  

   optimum 
  growth 
  either 
  in 
  lake 
  water 
  or 
  ordi- 
  

   nary 
  river 
  water 
  unless 
  rooted 
  in 
  the 
  soil, 
  

   although 
  a 
  substratum 
  of 
  sand 
  and 
  artificial 
  

   attachment 
  be 
  supplied, 
  it 
  remains 
  to 
  deter- 
  

   mine 
  whether 
  this 
  fact 
  may 
  be 
  due 
  to 
  insuffi- 
  

   cient 
  nourishment 
  in 
  the 
  water. 
  Again 
  , 
  from 
  

   the 
  a 
  priori 
  point 
  of 
  view, 
  if 
  these 
  plants 
  

   really 
  do 
  absorb 
  nourishment 
  over 
  their 
  en- 
  

   tire 
  surface, 
  they 
  ought 
  to 
  thrive 
  in 
  artificial 
  

   nutrient 
  solutions 
  of 
  suitable 
  strength 
  and 
  

   composition. 
  Knop's 
  solution 
  was 
  tried, 
  but 
  

   is 
  too 
  good 
  a 
  medium 
  for 
  the 
  growth 
  of 
  alga3. 
  

   Sachs's'' 
  solution 
  is 
  better, 
  and, 
  although 
  

   osmotically 
  stronger 
  than 
  tap 
  water, 
  is 
  still 
  

   safe 
  within 
  tlie 
  Ihiiit 
  of 
  suitable 
  strength. 
  

  

  In 
  the 
  two 
  succ^eeding 
  experiments 
  two 
  species 
  of 
  plants 
  were 
  grown 
  

   in 
  each 
  of 
  five 
  conditions, 
  namely: 
  

  

  "Sachs's 
  solution 
  is, 
  KNO3, 
  1 
  gram; 
  CaSO^, 
  0.5 
  grams; 
  MgS04, 
  0.5 
  grams; 
  NaCl, 
  

   0.5 
  grams; 
  Cag 
  (P04)2, 
  0.5 
  grams; 
  dissolved 
  in 
  water 
  to 
  1 
  liter. 
  

  

  Fig. 
  5. 
  — 
  Vallisneria 
  spiralis 
  after 
  

   5J 
  weeks' 
  growth 
  in 
  clay 
  soil 
  

  

  (No. 
  3). 
  

  

  