﻿LOBSTER 
  AND 
  CLAM 
  INVESTIGATIONS. 
  217 
  

  

  It 
  is 
  evident 
  that 
  no 
  oeneral 
  rule 
  can 
  be 
  given 
  for 
  the 
  spacing 
  of 
  

   clams. 
  Where 
  food-bearing 
  currents 
  are 
  rapid 
  clams 
  nui}^ 
  be 
  closeh^ 
  

   placed, 
  and 
  where 
  they 
  are 
  slow 
  the 
  spacing 
  must 
  be 
  greater. 
  Only 
  

   experiment 
  will 
  determine 
  the 
  optimum 
  space 
  for 
  a 
  given 
  area. 
  

  

  The 
  proper 
  number 
  of 
  clams 
  to 
  be 
  planted 
  on 
  anj 
  area 
  can 
  not 
  be 
  

   expressed 
  in 
  bulk 
  measurement. 
  In 
  an 
  earl}' 
  note 
  on 
  the 
  Essex 
  experi- 
  

   ment 
  in 
  clam 
  culture", 
  it 
  was 
  stated 
  that 
  clammers 
  estimated 
  that 
  500 
  

   l)ushels 
  of 
  small 
  clams 
  would 
  be 
  necessar}' 
  for 
  planting 
  1 
  acre. 
  Sup- 
  

   pose 
  that 
  clams 
  to 
  be 
  planted 
  varied 
  from 
  1 
  to 
  2 
  inches 
  in 
  length, 
  and 
  

   that 
  all 
  were 
  to 
  be 
  left 
  until 
  of 
  marketable 
  size. 
  If 
  planted 
  in 
  the 
  

   same 
  locality 
  they 
  would 
  require 
  an 
  equal 
  spacing. 
  But 
  assuming 
  

   that 
  1 
  bushel 
  contains 
  4,000 
  clams 
  1 
  inch 
  long, 
  it 
  would 
  require 
  nearl}^ 
  

   7 
  bushels 
  to 
  hold 
  4,000 
  clams 
  2 
  inches 
  long, 
  and 
  the 
  single 
  bushel 
  of 
  

   the 
  first 
  should 
  be 
  spread 
  over 
  as 
  great 
  an 
  area 
  as 
  the 
  7 
  bushels 
  of 
  the 
  

   larger 
  size. 
  Elven 
  if 
  beds 
  were 
  of 
  the 
  same 
  character 
  in 
  all 
  places 
  the 
  

   proper 
  number 
  to 
  be 
  planted 
  could 
  not 
  be 
  expressed 
  in 
  bulk 
  measure- 
  

   ment. 
  

  

  There 
  remains 
  to 
  be 
  described 
  the 
  growth 
  on 
  a 
  special 
  bed 
  with 
  

   which 
  extraordinary 
  pains 
  were 
  taken. 
  This 
  bed 
  was 
  selected 
  at 
  a 
  

   point 
  slightly 
  below 
  those 
  the 
  increase 
  of 
  which 
  has 
  been 
  described 
  in 
  

   the 
  second 
  table. 
  The 
  current 
  was 
  here 
  more 
  rapid, 
  and 
  the 
  clams 
  

   were 
  each 
  day 
  immersed 
  for 
  a 
  somewhat 
  longer 
  time. 
  The 
  bed 
  was 
  

   all 
  very 
  carefully' 
  tlug, 
  that 
  it 
  should 
  l)ear 
  no 
  clams 
  not 
  measured 
  and 
  

   planted. 
  In 
  it 
  were 
  placed 
  several 
  hundred 
  clams 
  exactly 
  1 
  inch 
  long. 
  

   They 
  were 
  in 
  good 
  condition 
  when 
  planted 
  on 
  August 
  17, 
  1899. 
  To 
  

   protect 
  the 
  bed 
  a 
  wire 
  netting 
  was 
  firmh' 
  fastened 
  over 
  it, 
  being 
  

   attached 
  to 
  iron 
  posts 
  and 
  held 
  down 
  in 
  various 
  places 
  by 
  long 
  wire 
  

   staples. 
  The 
  bed 
  certainly 
  was 
  not 
  touched 
  for 
  a 
  year. 
  

  

  On 
  August 
  16, 
  1900, 
  the 
  clams 
  were 
  removed. 
  Their 
  length 
  varied 
  

   from 
  2^ 
  to 
  2^^ 
  inches. 
  The 
  arithmetical 
  mean 
  of 
  the 
  series 
  was 
  18.969 
  

   eighths, 
  or 
  almost 
  2f 
  inches. 
  Comparing 
  the 
  volumes 
  of 
  clams 
  of 
  1 
  

   inch 
  and 
  2f 
  inches 
  it 
  was 
  found 
  that 
  the 
  latter 
  was 
  14.37 
  times 
  as 
  large 
  

   as 
  the 
  former, 
  or 
  that 
  there 
  had 
  been 
  an 
  increase 
  of 
  1,337 
  per 
  cent 
  in 
  

   volume. 
  This 
  amount 
  of 
  increase 
  is 
  represented 
  in 
  figure 
  9, 
  and 
  was 
  

   the 
  greatest 
  obtained 
  on 
  any 
  of 
  the 
  beds. 
  

  

  On 
  the 
  beach 
  above, 
  where 
  the 
  current 
  was 
  not 
  so 
  rapid 
  and 
  the 
  

   time 
  of 
  exposure 
  greater, 
  clams 
  of 
  the 
  same 
  length 
  increased 
  in 
  volume 
  

   ))ut 
  1,050 
  per 
  cent. 
  It 
  appears, 
  then, 
  that 
  rapidity 
  of 
  growth 
  depends 
  

   directly 
  upon 
  the 
  amount 
  of 
  food, 
  the 
  food 
  supply 
  depending 
  upon 
  the 
  

   velocity 
  of 
  the 
  current. 
  

  

  This 
  growth 
  took 
  place 
  upon 
  a 
  beach 
  and 
  not 
  upon 
  a 
  flat 
  where 
  cur- 
  

   rents 
  have 
  full 
  sweep. 
  A 
  feeble 
  current 
  ran 
  parallel 
  to 
  the 
  beach, 
  but 
  

   the 
  bed 
  itself 
  was 
  partially 
  surrounded 
  by 
  eelgrass. 
  The 
  food 
  supply 
  

   here 
  must 
  have 
  been 
  poorer 
  than 
  upon 
  many 
  clam 
  flats, 
  and 
  it 
  should 
  

  

  a 
  Report 
  of 
  the 
  U. 
  S. 
  Fish 
  Commission 
  for 
  1894. 
  

  

  