﻿iSpo.] 
  

  

  BOTANICAL 
  GAZETTE. 
  

  

  149 
  

  

  tn-e 
  plant 
  as 
  m 
  this 
  case. 
  The 
  submersed 
  leaves 
  were 
  also 
  

   somewhat 
  long 
  and 
  tapering, 
  as 
  in 
  var. 
  graminifolius, 
  but 
  

   the 
  stems 
  had 
  the 
  habit 
  of 
  var. 
  myriophyllus, 
  rooting 
  exten- 
  

   sively 
  and 
  sending 
  up 
  frequent 
  branches. 
  The 
  stipules, 
  too, 
  

  

  partook 
  of 
  the 
  tapering 
  character, 
  being 
  barelv 
  obtuse, 
  or 
  

  

  sometimes 
  acute. 
  But 
  the 
  fruit 
  in 
  both 
  forms" 
  is 
  identical 
  

   and 
  typical. 
  

  

  P. 
  heterophyllus, 
  as 
  ma}^ 
  be 
  seen 
  in 
  the 
  above 
  case, 
  fur- 
  

   nishes 
  a 
  good 
  illustration 
  of 
  one 
  mode 
  of 
  working 
  with 
  a 
  

   polymorphous 
  species, 
  and 
  shows 
  how 
  easy 
  it 
  is 
  to 
  be 
  led 
  to 
  

   make 
  varietal 
  distinctions 
  which 
  do 
  not 
  definitely 
  hold, 
  but 
  

   frequently 
  add 
  to 
  the 
  confusion 
  in 
  which 
  the 
  student 
  is 
  

   placed. 
  Having 
  collected 
  or 
  seen 
  this 
  plant 
  in 
  many 
  stations 
  

   and 
  numerous 
  examples 
  both 
  in 
  the 
  west 
  and 
  east, 
  I 
  have 
  

   generally 
  found 
  that 
  a 
  search 
  among 
  a 
  number 
  of 
  plants 
  of 
  

  

  ne 
  same 
  locality, 
  and 
  sometimes^ 
  an 
  examination 
  of 
  the 
  

   ieaves 
  on 
  the 
  same 
  stem, 
  will 
  show 
  transition 
  forms— 
  those' 
  

  

  napes 
  characteristic 
  of 
  one 
  extreme 
  being 
  sparsely 
  repre- 
  

   jnted 
  on 
  plants 
  whose 
  prevalent 
  shapes 
  are 
  of 
  the 
  other 
  

   ex 
  reme. 
  There 
  is 
  a 
  tendency, 
  however 
  wide 
  the 
  variation, 
  

   adhere 
  to 
  a 
  common 
  type, 
  which 
  may 
  be 
  eliminated 
  by 
  

   patient 
  study. 
  I 
  have 
  often 
  found 
  many 
  of 
  the 
  varietal 
  des- 
  

   ^fenations 
  of_ 
  botanists 
  more 
  bewildering 
  than 
  helpful, 
  for 
  

   ^ 
  nnecting^ 
  IJnks 
  are 
  quite 
  sure 
  to 
  appear 
  which 
  are 
  just 
  as 
  

   see 
  1 
  ^^^^^^ 
  among 
  the 
  varieties 
  as 
  to 
  the 
  type. 
  It 
  would 
  

   cov"^ 
  1? 
  , 
  " 
  ^^'^y 
  ^^ 
  enlarge 
  the 
  specific 
  description 
  so 
  as 
  

  

  er 
  all 
  but 
  very 
  pronounced 
  and 
  constant 
  varieties, 
  and 
  do 
  

   ^^\ay 
  with 
  some 
  of 
  the 
  hair-splitting 
  that 
  is 
  not 
  a 
  gain 
  to 
  

  

  mind^^' 
  ^" 
  ^^^^' 
  ^^*^ 
  ^"^ 
  ^" 
  variable 
  plants 
  something 
  to 
  re- 
  

   ren 
  • 
  ^^ 
  °^ 
  ^^^ 
  theory 
  of 
  the 
  great 
  German 
  artist 
  of 
  the 
  

   to 
  th'^^^"^^' 
  ^^^^"^cht 
  Diirer, 
  which 
  he 
  advanced 
  in 
  regard 
  

   that 
  "^^^^^^p"^ent 
  of 
  the 
  human 
  body. 
  It 
  was 
  in 
  substance 
  

   Pe'cuf'^ 
  ^^^^y 
  ^"ciividual 
  varies 
  from 
  the 
  typical 
  man 
  in 
  a 
  w^ay 
  

   ber 
  of^^ 
  ^° 
  himself, 
  these 
  variations 
  will, 
  in 
  an 
  infinite 
  num- 
  

   thg. 
  . 
  "^^^surements 
  counteract 
  and 
  destroy 
  each 
  other, 
  and 
  

   specf^^^^l^^ 
  ^^ 
  found. 
  It 
  might 
  be 
  well 
  for 
  the 
  makers 
  of 
  

   chara^V^ 
  '^' 
  *^^^^ 
  ^^ 
  mind 
  and 
  consider 
  as 
  one 
  those 
  whose 
  

   with 
  r 
  '".^ 
  overlap 
  too 
  for 
  and 
  which 
  can 
  not 
  be 
  differentiated 
  

   y 
  7^y 
  degree 
  of 
  definiteness. 
  

  

  