﻿574 
  Setchell: 
  The 
  :^iarine 
  spermatophytes 
  

  

  to 
  New 
  York 
  divided 
  between 
  the 
  Gray 
  Herbarium 
  and 
  that 
  of 
  

   the 
  New 
  York 
  Botanical 
  Garden. 
  The 
  specimens 
  of 
  the 
  southern 
  

   portion 
  of 
  this 
  part 
  of 
  the 
  range 
  are 
  largely, 
  although 
  not 
  entirely 
  

   the 
  broader 
  form 
  of 
  the 
  species. 
  Both 
  Britton 
  (1881, 
  p. 
  100 
  and 
  

   1889, 
  p. 
  259) 
  and 
  Stone 
  (191 
  1, 
  p. 
  166) 
  say 
  that 
  it 
  is 
  common 
  in 
  all 
  

   bays 
  along 
  the 
  coast 
  of 
  New 
  Jersey, 
  although 
  the 
  latter 
  adds 
  that 
  

   It 
  has 
  not 
  been 
  found 
  on 
  the 
  New 
  Jersey 
  shore 
  of 
  Delaware 
  Bay. 
  

   Stone 
  also 
  states 
  {loc. 
  cit,) 
  that 
  it 
  has 
  been 
  observed 
  In 
  flower 
  and 
  

   fruit 
  only 
  In 
  June 
  and 
  this 
  is 
  confirmed 
  in 
  a 
  letter 
  from 
  Bayard 
  

   Long, 
  while 
  above 
  Cape 
  Cod 
  it 
  is 
  in 
  fruit 
  in 
  August. 
  I 
  have 
  not 
  

   found 
  a 
  specimen 
  in 
  either 
  the 
  Gray 
  Herbarium 
  or 
  that 
  of 
  the 
  

   New 
  York 
  Botanical 
  Garden 
  from 
  any 
  part 
  of 
  our 
  eastern 
  coast 
  

   south 
  of 
  New 
  York 
  Harbor. 
  It 
  is 
  reported 
  as 
  frequent 
  in 
  shallow 
  

   water 
  in 
  Chincoteague 
  and 
  Chesapeake 
  Bays 
  on 
  the 
  coast 
  of 
  Mary- 
  

   land 
  by 
  Shreve, 
  Chrysler, 
  Blodgett 
  and 
  Besley 
  (1911, 
  p. 
  395), 
  and 
  

   there 
  is 
  certain 
  report 
  of 
  it 
  as 
  growing 
  in 
  abundance 
  on 
  the 
  northern 
  

   stretch 
  of 
  the 
  coast 
  of 
  North 
  Carolina. 
  The 
  only 
  locality 
  reported 
  

   south 
  of 
  North 
  Carolina 
  is 
  that 
  of 
  West 
  Florida. 
  This 
  was 
  made 
  

   by 
  Chapman 
  (i860, 
  p. 
  444) 
  and 
  repeated 
  by 
  Small 
  (1913, 
  p. 
  41), 
  

   but 
  I 
  can 
  find 
  no 
  specimen 
  to 
  verify 
  it. 
  Ascherson, 
  in 
  his 
  later 
  

  

  + 
  

  

  paper 
  on 
  the 
  distribution 
  of 
  the 
  ''sea-grasses" 
  (1906, 
  pp. 
  401, 
  402) 
  

   suggests 
  that 
  the 
  Florida 
  plant 
  was 
  probably 
  some 
  other 
  species 
  

   of 
  this 
  group. 
  Temperature 
  conditions 
  favor 
  West 
  Florida 
  as 
  a 
  

   possible 
  locality 
  for 
  its 
  growth. 
  In 
  his 
  Flora 
  of 
  Bermuda, 
  Britton 
  

   (1918, 
  p. 
  6) 
  designates^ 
  Zo^Vem 
  marina 
  as 
  a 
  ''native" 
  plant, 
  but 
  

   the 
  only 
  specimen 
  preserved 
  in 
  the 
  herbarium 
  of 
  the 
  New 
  York 
  

   Botanical 
  Garden 
  and 
  labelled 
  as 
  from 
  Bermuda 
  consists 
  of 
  en- 
  

   tangled 
  leaves 
  evidently 
  cast 
  ashore, 
  but 
  is 
  supposed 
  to 
  have 
  come 
  

   from 
  nearby 
  shoals. 
  It 
  is 
  to 
  be 
  noted 
  that 
  this 
  specimen 
  is 
  

   plainly 
  of 
  the 
  broad-leaved 
  typical 
  form 
  of 
  the 
  species. 
  It 
  does 
  

   not 
  seem 
  to 
  occur 
  in 
  the 
  Bahama 
  Islands. 
  

  

  In 
  attempting 
  to 
  deduce 
  from 
  the 
  data 
  of 
  distribution 
  as 
  I 
  

   have 
  outlined 
  them, 
  the 
  true 
  conditions 
  and 
  laws 
  of 
  distribution 
  

   of 
  Zostera 
  marina, 
  there 
  are 
  certain 
  considerations 
  which 
  stand 
  

   out 
  as 
  of 
  importance. 
  I 
  shall 
  divide 
  them 
  under 
  six 
  heads, 
  as 
  

   follows 
  : 
  

  

  (i) 
  Zostera 
  marina, 
  as 
  estimated 
  taxonomlcally, 
  probably 
  

   consists 
  of 
  two 
  or 
  more 
  genetic 
  entities 
  which 
  seem 
  to 
  have 
  

  

  