﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  213 
  

  

  10 
  feet 
  square. 
  A 
  light, 
  portable 
  frame 
  of 
  the 
  same 
  dimensions 
  was 
  

   constrnctod 
  and 
  divided 
  into 
  square 
  feet 
  by 
  means 
  of 
  small 
  ropes. 
  At 
  

   the 
  time 
  of 
  plantin<»', 
  this 
  frame 
  was 
  placed 
  upon 
  a 
  bed, 
  just 
  fitting 
  

   between 
  the 
  stakes, 
  and 
  clams 
  were 
  placed 
  in 
  any 
  of 
  the 
  small 
  squares, 
  

   a 
  record 
  of 
  size 
  and 
  number 
  being- 
  made 
  in 
  the 
  corresponding 
  square 
  

   of 
  a 
  diagram 
  in 
  a 
  notebook. 
  When 
  clams 
  were 
  removed 
  the 
  frame 
  

   was 
  again 
  placed 
  in 
  its 
  original 
  position. 
  

  

  It 
  should 
  be 
  said 
  that 
  clams 
  of 
  the 
  size 
  of 
  those 
  planted 
  do 
  not 
  remove 
  

   themselves 
  from 
  their 
  burrows, 
  but 
  remain 
  where 
  they 
  are 
  placed. 
  It 
  

   has 
  been 
  stated 
  that 
  small 
  individuals 
  wander, 
  but 
  the 
  habit 
  seems 
  to 
  

   be 
  abandoned 
  before 
  they 
  are 
  an 
  inch 
  long. 
  

  

  As 
  already 
  explained, 
  clams 
  were 
  measured 
  in 
  length 
  before 
  plant- 
  

   ing 
  and 
  again 
  after 
  a 
  year 
  of 
  growth, 
  to 
  determine 
  the 
  increase. 
  A 
  

   statement 
  of 
  the 
  increase 
  in 
  length 
  gives 
  no 
  adequate 
  idea 
  of 
  the 
  actual 
  

   increase 
  in 
  size, 
  however. 
  This 
  increase 
  in 
  volume 
  was 
  determined 
  

   by 
  displacement 
  in 
  water. 
  A 
  clam 
  1 
  inch 
  in 
  length 
  diplaces 
  approx- 
  

   imatel}" 
  2.25 
  cc. 
  of 
  water. 
  One 
  2 
  inches 
  long 
  displaces 
  about 
  11 
  cc, 
  

   or 
  nearly 
  five 
  times 
  as 
  much. 
  An 
  individual 
  measuring 
  3 
  inches 
  dis- 
  

   places 
  about 
  43 
  cc, 
  or 
  is 
  about 
  nineteen 
  times 
  as 
  large. 
  In 
  measuring- 
  

   displacements, 
  results 
  var}^ 
  in 
  difi'erent 
  cases. 
  Some 
  individuals 
  are 
  

   thick 
  and 
  wide, 
  others 
  narrow 
  in 
  proportion 
  to 
  the 
  length 
  of 
  the 
  shell. 
  

   When 
  being 
  measured 
  some 
  are 
  more 
  contracted 
  than 
  others. 
  Thus 
  

   a 
  comparatively 
  large 
  number 
  was 
  measured 
  in 
  order 
  to 
  determine 
  the 
  

   average 
  displacement 
  in 
  each 
  set, 
  and 
  the 
  results 
  obtained 
  are 
  accurate 
  

   enough 
  for 
  the 
  purpose. 
  

  

  In 
  order 
  to 
  be 
  certain 
  of 
  the 
  position 
  of 
  individuals 
  in 
  the 
  beds, 
  a 
  

   sharp-pointed 
  stake 
  was 
  driven 
  into 
  the 
  ground 
  to 
  a 
  depth 
  of 
  several 
  

   inches, 
  and 
  on 
  its 
  withdrawal 
  a 
  clam 
  was 
  thrust 
  siphon 
  end 
  uppermost 
  

   into 
  the 
  hole. 
  Working 
  in 
  this 
  manner, 
  it 
  was 
  possible 
  to 
  place 
  them 
  

   with 
  some 
  rapidit}'. 
  Upon 
  a 
  hard, 
  gravell}^ 
  beach, 
  four 
  men 
  at 
  one 
  

   time 
  planted 
  3,000 
  in 
  two 
  hours. 
  In 
  a 
  soft 
  beach 
  twice 
  that 
  number 
  

   might 
  have 
  been 
  phmted 
  in 
  the 
  same 
  time. 
  There 
  seems 
  to 
  be 
  no 
  

   reason 
  to 
  doubt 
  that 
  clams 
  finally 
  removed 
  from 
  an}^ 
  square 
  were 
  the 
  

   ones 
  original!}^ 
  placed 
  there. 
  The 
  beds 
  were 
  prol)ably 
  not 
  molested 
  

   by 
  clam 
  diggers. 
  There 
  was 
  some 
  apprehension 
  lest, 
  during 
  the 
  

   winter, 
  ice 
  should 
  destroj^ 
  the 
  stakes 
  marking 
  the 
  corners 
  of 
  the 
  beds. 
  

   Fortunately 
  not 
  a 
  stake 
  was 
  removed 
  or 
  broken. 
  

  

  Clams 
  all 
  of 
  the 
  same 
  length 
  when 
  planted 
  will 
  of 
  course 
  vary 
  some- 
  

   what 
  in 
  size 
  after 
  a 
  year's 
  growth. 
  When 
  these 
  were 
  dug, 
  they 
  were 
  

   again 
  measured 
  and 
  arranged 
  in 
  a 
  series 
  of 
  different 
  sizes, 
  the 
  number 
  

   in 
  each 
  set 
  being 
  counted. 
  The 
  arithmetical 
  mean 
  of 
  the 
  series 
  was 
  

   then 
  determined. 
  The 
  volume 
  of 
  the 
  mean 
  of 
  the 
  series 
  was 
  compared 
  

   with 
  the 
  volume 
  of 
  the 
  clams 
  when 
  planted, 
  and 
  the 
  percentage 
  of 
  

   increase 
  in 
  volume 
  calculated. 
  For 
  example, 
  in 
  a 
  certain 
  bed 
  planted 
  

   on 
  July 
  13, 
  1899, 
  the 
  clams 
  were 
  1| 
  inches 
  long. 
  They 
  were 
  removed 
  

  

  