﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  221 
  

  

  was 
  enough 
  to 
  injure 
  them 
  to 
  such 
  an 
  extent 
  that 
  death 
  quickl}^ 
  fol- 
  

   lowed 
  after 
  planting-. 
  Exposure 
  under 
  these 
  conditions 
  for 
  36 
  hours 
  

   led 
  to 
  the 
  death 
  of 
  man}-, 
  but 
  those 
  which 
  had 
  ])een 
  out 
  of 
  water 
  for 
  a 
  

   day, 
  even 
  when 
  exposed 
  directly 
  to 
  the 
  sun 
  for 
  some 
  time, 
  as 
  a 
  rule 
  

   seemed 
  to 
  be 
  injured 
  very 
  little. 
  

  

  For 
  example, 
  of 
  a 
  large 
  number 
  dug 
  on 
  one 
  low-tide, 
  several 
  were 
  

   planted 
  24 
  hours 
  later, 
  and 
  many 
  survived. 
  The 
  remainder 
  of 
  the 
  

   same 
  lot 
  was 
  planted 
  under 
  similar 
  conditions 
  after 
  48 
  hours 
  of 
  expo- 
  

   sure, 
  and 
  almost 
  all 
  died. 
  Their 
  shells 
  showed 
  that 
  thev 
  perished 
  

   before 
  an}^ 
  growth 
  had 
  taken 
  place. 
  None 
  were 
  crowded 
  in 
  planting, 
  

   and 
  the 
  tide 
  currents 
  were 
  more 
  rapid 
  than 
  on 
  the 
  majority 
  of 
  the 
  

   beds. 
  In 
  this 
  case 
  the 
  destruction 
  probably 
  should 
  be 
  ascribed 
  not 
  to 
  

   the 
  contamination 
  of 
  soil 
  and 
  water 
  by 
  the 
  decajang 
  bodies 
  of 
  a 
  few, 
  

   but 
  rather 
  to 
  the 
  fact 
  that 
  all 
  had 
  been 
  too 
  long 
  exposed 
  before 
  planting. 
  

  

  Several 
  similar 
  cases 
  were 
  noticed, 
  and 
  it 
  seems 
  safe 
  to 
  conclude 
  

   that 
  during 
  the 
  hot 
  summer 
  months 
  clams 
  for 
  planting 
  can 
  not 
  be 
  

   exposed 
  safel}^ 
  longer 
  than 
  a 
  day. 
  In 
  culture 
  work 
  this 
  would 
  not 
  

   often 
  be 
  necessary. 
  

  

  TRANSFER 
  OF 
  CLAMS 
  FROM 
  FRESH 
  TO 
  SALT 
  WATER. 
  

  

  Clams 
  frequently 
  are 
  found 
  in 
  localities 
  where 
  the 
  water 
  is 
  nearly 
  

   fresh. 
  In 
  such 
  regions 
  diatoms 
  are 
  usually 
  abundant, 
  and 
  clams 
  flour- 
  

   ish. 
  Near 
  Falmouth 
  Heights 
  a 
  large, 
  nearlj^ 
  fresh 
  pond 
  supports 
  many 
  

   clams, 
  and 
  several 
  thousand 
  of 
  these 
  were 
  transplanted 
  directly 
  to 
  the 
  

   very 
  salt 
  water 
  at 
  Woods 
  Hole. 
  When 
  not 
  too 
  long 
  exposed 
  in 
  the 
  

   transfer, 
  they 
  seemed 
  to 
  be 
  entirely 
  unafi'ected 
  b}^ 
  the 
  change, 
  and 
  

   grew 
  exactly 
  as 
  well 
  as 
  others 
  planted 
  near 
  them 
  which 
  had 
  been 
  taken 
  

   from 
  the 
  salt 
  water 
  of 
  Buzzards 
  Bay. 
  Though 
  an 
  attempt 
  was 
  made 
  

   to 
  transfer 
  clams 
  from 
  salt 
  water 
  to 
  this 
  fresh-water 
  pond, 
  the 
  time 
  

   was 
  too 
  short 
  to 
  prepare 
  a 
  bed 
  properh' 
  by 
  removing 
  clams 
  already 
  

   present 
  in 
  it, 
  and 
  the 
  results 
  are 
  not 
  to 
  be 
  depended 
  upon. 
  The 
  

   transfer 
  from 
  salt 
  to 
  fresh 
  water 
  probably 
  could 
  be 
  made 
  as 
  well, 
  

   however, 
  and 
  this 
  possibility 
  of 
  ready 
  transfer 
  is 
  a 
  point 
  of 
  importance, 
  

   for 
  small 
  clams 
  often 
  may 
  be 
  abundant 
  in 
  waters 
  of 
  one 
  density 
  near 
  

   favorable 
  planting 
  grounds 
  of 
  another. 
  

  

  In 
  many, 
  if 
  not 
  in 
  the 
  majorit}", 
  of 
  marine 
  animals 
  a 
  more 
  or 
  less 
  

   definite 
  amount 
  of 
  salt 
  in 
  the 
  water 
  is 
  necessary 
  for 
  their 
  existence. 
  

   Even 
  in 
  the 
  case 
  of 
  oysters, 
  which 
  are 
  near 
  relatives 
  of 
  the 
  clam, 
  a 
  

   slight 
  variation 
  in 
  density 
  determines 
  whether 
  they 
  may 
  live 
  or 
  

   not. 
  While 
  it 
  is 
  true 
  that 
  the 
  life 
  of 
  individuals 
  may 
  not 
  suddenly 
  be 
  

   ended 
  when 
  they 
  are 
  placed 
  in 
  water 
  more 
  or 
  less 
  salt 
  than 
  the 
  nor- 
  

   mal 
  amount, 
  it 
  is 
  also 
  true 
  that 
  reproduction 
  is 
  interfered 
  with, 
  or 
  

   even 
  entirely 
  prevented 
  by 
  the 
  slightest 
  changes. 
  The 
  American 
  

   oyster 
  differs 
  from 
  the 
  European 
  species 
  in 
  its 
  requirements 
  and 
  per- 
  

  

  