﻿Nichols: 
  The 
  vegetation 
  of 
  Connecticut 
  93 
  

  

  day 
  they 
  are 
  exposed 
  to 
  the 
  air 
  and 
  therefore 
  must 
  be 
  able 
  to 
  

   endure, 
  in 
  varying 
  degree, 
  desiccation, 
  exposure 
  to 
  rain 
  water, 
  

   and 
  intense 
  illumination, 
  not 
  to 
  mention 
  freezing 
  temperatures 
  

   in 
  Avinter, 
  Similarly, 
  halophytic 
  seed 
  plants 
  which 
  grow 
  in 
  areas 
  

   that 
  are 
  permanently 
  or 
  intermittently 
  submerged 
  must 
  be 
  able 
  

   to 
  accommodate 
  themselves, 
  for 
  longer 
  or 
  shorter 
  periods, 
  to 
  

   poor 
  aeration 
  and 
  weak 
  illumination. 
  It 
  is 
  the 
  varyhig 
  degree 
  

   to 
  which 
  seaweeds 
  and 
  seed 
  plants 
  are 
  adapted 
  to 
  these 
  diverse 
  

   environmental 
  conditions 
  that 
  in 
  large 
  part 
  is 
  responsible 
  for 
  the 
  

   zonal 
  arrangement 
  of 
  plant 
  associations 
  in 
  relation 
  to 
  tide 
  levels 
  

   (Fig. 
  5), 
  which 
  constitutes 
  one 
  of 
  the 
  most 
  striking 
  features 
  of 
  

   seaside 
  vegetation. 
  

  

  The 
  range 
  of 
  the 
  tides 
  along 
  the 
  Connecticut 
  coast, 
  i.e.^ 
  the 
  

   difference 
  between 
  high 
  and 
  low 
  tide 
  levels, 
  varies 
  greatly 
  in 
  

   different 
  localities. 
  The 
  average 
  daily 
  range 
  at 
  Greenwich, 
  toward 
  

   the 
  western 
  extremity 
  of 
  the 
  Connecticut 
  shore 
  line 
  and 
  tow^ard 
  

   the 
  head 
  of 
  the 
  Sound, 
  is 
  nearly 
  three 
  times 
  that 
  at 
  New 
  London, 
  

   toward 
  the 
  eastern 
  end 
  of 
  the 
  shore 
  line 
  and 
  just 
  outside 
  the 
  

   entrance 
  to 
  the 
  Sound. 
  Proceeding 
  from 
  east 
  to 
  west 
  along 
  

   the 
  Connecticut 
  shore, 
  the 
  mean 
  daily 
  tidal 
  ranges 
  at 
  various 
  

   stations 
  are: 
  Stonington, 
  2.7 
  feet; 
  New 
  London, 
  2.5 
  feet; 
  Say- 
  

   brook, 
  3.6 
  feet; 
  New 
  Haven, 
  6 
  feet; 
  Greenwich, 
  74 
  feet. 
  As 
  else- 
  

   where 
  along 
  oceanic 
  coasts, 
  however, 
  the 
  tidal 
  range 
  for 
  any 
  

   given 
  locality 
  is 
  not 
  constant, 
  but 
  varies 
  from 
  time 
  to 
  time. 
  The 
  

   most 
  important 
  of 
  these 
  variations 
  are 
  seen 
  in 
  the 
  semi-monthly 
  

   spring 
  and 
  neap 
  tides. 
  The 
  spring 
  tides, 
  occurring 
  just 
  after 
  

   the 
  new 
  moon 
  and 
  the 
  full 
  moon 
  each 
  month, 
  have 
  a 
  range 
  from 
  

   sixteen 
  to 
  tw^enty 
  per 
  cent 
  greater 
  than 
  the 
  average, 
  and 
  about 
  

   twice 
  that 
  of 
  the 
  neap 
  tides, 
  which 
  occur 
  just 
  after 
  the 
  first 
  and 
  

   last 
  quarters 
  of 
  the 
  moon. 
  The 
  equinoctial 
  high 
  tides, 
  which 
  

   occur 
  at 
  about 
  the 
  time 
  of 
  the 
  equinoxes, 
  rise 
  considerably 
  higher 
  

   than 
  the 
  spring 
  tides; 
  while 
  storm 
  tides, 
  especially 
  those 
  in 
  w^hich 
  

   the 
  spring 
  tides 
  are 
  coincident 
  with 
  strong 
  onshore 
  gales, 
  may 
  rise 
  

   from 
  three 
  to 
  five 
  feet 
  higher 
  than 
  the 
  mean 
  high 
  tide 
  level. 
  

  

  Illumination 
  at 
  different 
  depths.—ln 
  proceeding 
  from 
  high 
  tide 
  

   mark 
  downward 
  into 
  the 
  depths 
  of 
  the 
  sea 
  there 
  is 
  a 
  gradual 
  

  

  see 
  

  

  Wheeler 
  Co6). 
  

  

  