﻿502 
  EEPOET 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  the 
  5 
  or 
  6 
  lowest 
  nodes. 
  These 
  roots 
  had 
  no 
  branches. 
  The 
  plants 
  rooted 
  in 
  sand 
  

   had 
  numerous 
  roots 
  which 
  were 
  longer 
  than 
  those 
  of 
  the 
  anchored 
  plants, 
  profusely 
  

   branched 
  and 
  white. 
  The 
  plants 
  rooted 
  in 
  soil 
  wei-e 
  about 
  equal 
  to 
  those 
  rooted 
  in 
  sand 
  

   in 
  root 
  development, 
  but 
  the 
  roots 
  were 
  of 
  a 
  dark 
  purple 
  color, 
  which 
  is 
  common, 
  

   though 
  not 
  universal, 
  in 
  wild 
  specimens. 
  None 
  of 
  the 
  roots 
  arose 
  from 
  nodes 
  above 
  

   earthy 
  substratum. 
  The 
  internodes 
  in 
  all 
  cases 
  were 
  of 
  about 
  equal 
  length. 
  The 
  

   only 
  difference 
  seemed 
  to 
  be 
  merely 
  that 
  there 
  was 
  more 
  growth 
  in 
  the 
  plants 
  rooted 
  

   in 
  soil. 
  

  

  Groivth 
  measuremenla 
  of 
  Myrioplaillum 
  spicatum 
  at 
  the 
  end 
  of 
  SI 
  days, 
  

   of 
  each 
  ndtiny, 
  15 
  cm. 
  

  

  Ongincd 
  length 
  

  

  The 
  measurements 
  in 
  the 
  accompanying 
  tables 
  show: 
  

  

  (1) 
  A 
  positive 
  ditierence 
  in 
  favor 
  of 
  plants 
  rooted 
  in 
  soil. 
  

  

  (2) 
  The 
  two 
  groups 
  of 
  anchored 
  plants 
  are 
  practically 
  alike. 
  

  

  (3) 
  The 
  plants 
  rooted 
  in 
  sand 
  exceed 
  those 
  anchored, 
  but 
  do 
  not 
  

   approach 
  in 
  growth 
  those 
  rooted 
  in 
  soil. 
  

  

  ELODKA 
  CANADENSIS. 
  

  

  Either 
  still 
  or 
  running 
  water 
  is 
  suitable 
  for 
  Elodea. 
  It 
  grows 
  

   attached 
  to 
  the 
  substratiun 
  by 
  adventitious 
  roots 
  arising 
  at 
  the 
  nodes. 
  

   I 
  have 
  never 
  found 
  lateral 
  branches 
  on 
  the 
  roots, 
  although 
  I 
  have 
  made 
  

   several 
  attempts 
  to 
  do 
  so. 
  The 
  plant 
  thrives 
  in 
  shallow 
  or 
  deep 
  water 
  

   and 
  seems 
  to 
  be 
  adapted 
  to 
  light 
  of 
  varj-ing 
  intensit}'. 
  When 
  growing 
  

   in 
  water 
  a 
  meter 
  or 
  two 
  in 
  depth 
  the 
  internodes 
  are 
  noticeably 
  longer, 
  

   the 
  stem 
  thicker 
  and 
  less 
  branched. 
  Roots 
  arise 
  quickly 
  from 
  the 
  

   nodes 
  of 
  a 
  drifting 
  fragment. 
  At 
  Put-in 
  Bay 
  a 
  large 
  thrifty 
  plant 
  

   was 
  found 
  atioat, 
  which 
  bore 
  a 
  single 
  root 
  90 
  cm. 
  in 
  length. 
  Elodea 
  

   likes 
  a 
  good 
  loani}^ 
  soil. 
  It 
  does 
  occur 
  in 
  cky, 
  and 
  may 
  frequentlv 
  be 
  

   noticed 
  growing 
  clustered 
  in 
  what 
  appears 
  to 
  be 
  a 
  sand 
  substratum, 
  

   but 
  I 
  have 
  always 
  found 
  some 
  humus 
  soil 
  present 
  in 
  such 
  cases. 
  

  

  Experiment 
  No. 
  6. 
  — 
  The 
  location 
  and 
  conditions 
  are 
  continued 
  here 
  as 
  in 
  preceding 
  

   experiments, 
  the 
  duration 
  being 
  one 
  month, 
  July 
  10 
  to 
  August 
  10. 
  Terminal 
  cut- 
  

   tings 
  10 
  cm. 
  long 
  were 
  selected 
  from 
  fresh 
  river 
  specimens. 
  These 
  cuttings 
  were 
  

   alike 
  in 
  all 
  respects, 
  and 
  were 
  without 
  roots 
  or 
  branches. 
  

  

  On 
  August 
  10 
  little 
  difference, 
  if 
  any, 
  could 
  be 
  noticed 
  in 
  the 
  plants 
  rooted 
  in 
  

   sand, 
  anchored 
  over 
  soil 
  or 
  anchored 
  over 
  sand. 
  The 
  diameter 
  of 
  the 
  stem 
  and 
  the 
  

  

  