﻿492 
  REPORT 
  O^ 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  In 
  Vines's 
  Text-book 
  (1896) 
  is 
  the 
  statement 
  that 
  " 
  submerged 
  aquatic 
  

   plants 
  absorb 
  their 
  food 
  entirely 
  or 
  mainl}^ 
  from 
  the 
  water 
  in 
  which 
  

   they 
  live." 
  Coulter 
  (1900) 
  agrees 
  with 
  the 
  opinions 
  of 
  Schenck 
  and 
  

   Strasburger. 
  

  

  The 
  literature 
  thus 
  far 
  reviewed 
  permits 
  one 
  to 
  consider 
  these 
  writers 
  

   in 
  two 
  groups, 
  one 
  including 
  those 
  whose 
  opinions 
  are 
  derived 
  a 
  priori, 
  

   assuming 
  that 
  the 
  plants 
  are 
  surrounded 
  by 
  a 
  nutritive 
  solution 
  and 
  

   that 
  absorption 
  can 
  take 
  place 
  through 
  the 
  epidermis; 
  the 
  other 
  in- 
  

   cluding 
  those 
  who 
  have 
  investigated 
  and 
  who 
  feel 
  warranted 
  in 
  con- 
  

   cluding 
  that 
  these 
  aquatics 
  obtain 
  their 
  nourishment 
  by 
  a 
  process 
  

   comparable 
  to 
  that 
  of 
  terrestrial 
  plants. 
  

  

  Pfeffer 
  (1897) 
  expresses 
  the 
  opinion 
  that 
  a 
  circulation 
  of 
  water 
  in 
  

   aquatic 
  plants 
  is 
  possible, 
  and 
  he 
  reviews 
  the 
  literature 
  briefly, 
  stating 
  

   that 
  the 
  experiments 
  of 
  Unger, 
  Wieler, 
  and 
  Hochreutiner 
  are 
  not 
  

   conclusive, 
  and 
  that 
  the 
  opinions 
  of 
  Strasburger 
  and 
  Sauvageau 
  are 
  

   not 
  supported 
  by 
  experimental 
  evidence. 
  Also, 
  on 
  page 
  297, 
  Pfefler 
  

   says 
  that 
  no 
  decisive 
  experiments 
  concerning 
  excretion 
  of 
  water 
  in 
  

   submerged 
  or 
  amphibious 
  plants 
  have 
  yet 
  been 
  made. 
  

  

  The 
  preceding 
  review 
  of 
  literature 
  deals 
  more 
  particularly 
  with 
  

   the 
  work 
  and 
  opinions 
  of 
  botanists 
  and 
  shows 
  that 
  they 
  are 
  by 
  no 
  

   means 
  in 
  agreement. 
  On 
  the 
  other 
  hand, 
  however, 
  those 
  who 
  have 
  

   dealt 
  with 
  the 
  subject 
  from 
  a 
  more 
  general 
  botanical 
  or 
  biological 
  

   standpoint 
  have 
  given 
  reason 
  for 
  belief 
  that 
  rooted 
  aquatic 
  plants 
  

   derive 
  nourishment 
  from 
  the 
  soil. 
  Seligo 
  (1890, 
  p. 
  48) 
  expresses 
  the 
  

   opinion 
  that 
  the 
  fertility 
  of 
  the 
  bottom 
  should 
  have 
  an 
  effect 
  on 
  the 
  

   development 
  of 
  shore 
  plants, 
  and 
  points 
  out 
  that 
  in 
  regions 
  where 
  the 
  

   soil 
  of 
  the 
  adjacent 
  land 
  is 
  fertile 
  the 
  shore 
  region 
  of 
  the 
  lakes 
  is 
  

   almost 
  everywhere 
  better 
  covered 
  with 
  vegetation 
  than 
  in 
  sterile 
  

   regions. 
  He 
  then 
  says: 
  " 
  Yet 
  this 
  influence 
  is 
  not 
  so 
  decisive 
  as 
  it 
  

   appears 
  to 
  be, 
  for 
  a 
  great 
  part 
  of 
  the 
  shore 
  vegetation 
  (algai) 
  takes 
  its 
  

   nourishment, 
  not 
  from 
  the 
  bottom, 
  but 
  from 
  the 
  water." 
  Seligo 
  thus, 
  

   by 
  implication, 
  expresses 
  his 
  belief 
  that 
  larger 
  aquatics 
  draw 
  their 
  

   nourishment 
  from 
  the 
  soil. 
  

  

  Stockmayer 
  (1894, 
  p. 
  136) 
  cites 
  a 
  case 
  in 
  which 
  an 
  alga 
  {Desmonema 
  

   wrangeUi) 
  appears 
  to 
  depend 
  on 
  a 
  substratum 
  of 
  gneiss. 
  

  

  Pieters 
  (1901^ 
  p. 
  75), 
  in 
  his 
  work 
  on 
  the 
  plants 
  of 
  Lake 
  Erie, 
  showed 
  

   that 
  there 
  is 
  a 
  probable 
  relation 
  between 
  the 
  abundance 
  of 
  aquatic 
  

   vegetation 
  and 
  the 
  character 
  of 
  the 
  bottom 
  soil 
  as 
  revealed 
  by 
  mechan- 
  

   ical 
  analysis. 
  "As 
  a 
  rule, 
  the 
  soils 
  on 
  which 
  the 
  plants 
  occurred 
  in 
  

   abundance 
  were 
  composed 
  largely 
  of 
  sand 
  and 
  very 
  tine 
  sand, 
  and 
  con- 
  

   tained 
  relatively 
  little 
  silt, 
  fine 
  silt, 
  and 
  clay, 
  while 
  the 
  soils 
  on 
  which 
  

   few 
  or 
  no 
  plants 
  occurred, 
  although 
  the 
  depth 
  of 
  the 
  water 
  and 
  other 
  

   physical 
  conditions 
  were 
  favorable, 
  were 
  composed 
  largely 
  of 
  silt, 
  tine 
  

   silt, 
  and 
  clay, 
  and 
  were 
  poor 
  in 
  fine 
  sand 
  and 
  very 
  tine 
  sand." 
  

  

  