﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  2l9 
  

  

  by 
  the 
  rapidity 
  with 
  which 
  the 
  currents 
  carried 
  away 
  decaying 
  matter. 
  

   Growth 
  may 
  have 
  continued 
  until, 
  from 
  the 
  effects 
  of 
  crowding, 
  oth- 
  

   ers 
  died, 
  and 
  this 
  process 
  finally 
  left 
  only 
  the 
  few. 
  

  

  Two 
  other 
  beds 
  may 
  be 
  cited 
  as 
  illustrations 
  of 
  this 
  point. 
  They 
  

   were 
  placed 
  on 
  the 
  same 
  beach 
  where 
  the 
  most 
  rapid 
  growth 
  was 
  

   obtained. 
  Each 
  contained 
  150 
  square 
  feet 
  and 
  extended 
  from 
  near 
  

   high 
  water 
  below 
  ordinary 
  low 
  water. 
  In 
  the 
  first, 
  1,900 
  clams 
  were 
  

   planted, 
  varying 
  from 
  1 
  to 
  li 
  inches. 
  In 
  the 
  second 
  were 
  placed 
  1,200 
  

   clams 
  of 
  the 
  same 
  sizes. 
  All 
  seemed 
  to 
  be 
  in 
  perfect 
  condition. 
  

  

  In 
  a 
  year's 
  time 
  almost 
  all 
  were 
  dead 
  on 
  both 
  beds. 
  An 
  examination 
  

   ■^-evealed 
  shells 
  of 
  all 
  sizes 
  up 
  to 
  about 
  2.5 
  inches. 
  The 
  few 
  living 
  

   clams 
  were 
  nearh^ 
  3 
  inches 
  long. 
  The 
  great 
  majority 
  of 
  the 
  empt}^ 
  

   shells 
  were 
  very 
  little 
  larger 
  than 
  those 
  planted, 
  so 
  that 
  death 
  must 
  

   have 
  overtaken 
  them 
  soon 
  after 
  being 
  put 
  in 
  the 
  ground. 
  Death 
  from 
  

   lack 
  of 
  food 
  or 
  from 
  in]\uy 
  may 
  have 
  occurred 
  in 
  a 
  few 
  individuals. 
  

   The 
  decaj^ing 
  bodies 
  of 
  these 
  may 
  in 
  turn 
  have 
  caused 
  the 
  death 
  of 
  

   others, 
  and 
  this 
  must 
  have 
  come 
  about 
  quickly. 
  

  

  Which 
  is 
  more 
  important 
  in 
  accounting 
  for 
  this 
  destruction, 
  lack 
  of 
  

   food 
  or 
  contamination 
  of 
  the 
  water, 
  it 
  is 
  difficult 
  to 
  say. 
  Scarcity 
  of 
  

   food 
  alone 
  may 
  account 
  for 
  it 
  up 
  to 
  a 
  certain 
  point, 
  as 
  explained 
  in 
  

   connection 
  with 
  the 
  death 
  of 
  small 
  clams 
  on 
  natural 
  beds; 
  but 
  finally 
  

   there 
  should 
  have 
  been 
  a 
  certain 
  percentage 
  remaining 
  for 
  which 
  food 
  

   in 
  the 
  water 
  was 
  sufficient. 
  Nearly 
  all 
  died, 
  however, 
  and 
  it 
  is 
  not 
  

   easy 
  to 
  see 
  why 
  the}^ 
  should, 
  unless 
  it 
  may 
  have 
  been 
  from 
  this 
  infec- 
  

   tion 
  of 
  the 
  water 
  by 
  the 
  bodies 
  of 
  dead 
  clams. 
  At 
  all 
  events 
  there 
  are 
  

   several 
  cases 
  to 
  show 
  that 
  too 
  great 
  crowding 
  is 
  likely 
  to 
  lead 
  to 
  the 
  

   loss 
  of 
  all 
  clams 
  planted 
  together. 
  Where 
  currents 
  are 
  rapid 
  more 
  

   clams 
  may 
  live 
  than 
  where 
  they 
  are 
  slow, 
  and 
  the 
  capacity 
  of 
  any 
  

   beach 
  or 
  flat 
  must 
  be 
  determined 
  by 
  experiment, 
  

  

  THE 
  CHARACTER 
  OF 
  THE 
  BOTTOM 
  INFLUENCING 
  GROWTH. 
  

  

  Natural 
  beds 
  are 
  found 
  on 
  muddy, 
  sandy, 
  or 
  rocky 
  beaches. 
  

   Whether 
  soft 
  or 
  hard, 
  the 
  bottom 
  merely 
  offers 
  protection 
  from 
  ene- 
  

   mies. 
  Buried 
  under 
  several 
  inches, 
  the 
  clam 
  reaches 
  to 
  the 
  surface 
  

   with 
  its 
  siphons. 
  Through 
  them 
  one 
  current 
  of 
  water 
  bearing 
  micro- 
  

   scopic 
  food 
  is 
  led 
  down 
  to 
  the 
  body 
  within 
  the 
  shell 
  and 
  another 
  passes 
  

   out 
  bearing 
  waste 
  matter. 
  

  

  It 
  may 
  be 
  assumed 
  that 
  the 
  abundance 
  of 
  food 
  in 
  the 
  water 
  is 
  the 
  

   only 
  important 
  feature 
  of 
  the 
  surroundings, 
  but, 
  in 
  some 
  ways, 
  the 
  

   character 
  of 
  the 
  soil 
  may 
  also 
  be 
  important. 
  Two 
  beds 
  were 
  marked 
  

   in 
  a 
  soft 
  bottom 
  which 
  contained 
  much 
  decaying 
  vegetable 
  matter. 
  

   Other 
  conditions 
  seemed 
  to 
  be 
  much 
  as 
  in 
  the 
  neighboring 
  beds. 
  The 
  

   surface 
  of 
  this 
  peaty 
  mass 
  did 
  not 
  shift. 
  Water 
  currents, 
  food, 
  and 
  

   exposure 
  by 
  tides 
  were 
  certainly 
  not 
  very 
  different 
  on 
  other 
  produc- 
  

  

  