﻿382 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  From 
  this 
  it 
  seems 
  probable 
  that 
  the 
  presence 
  of 
  mud, 
  while 
  it 
  sac 
  

   rifices 
  many 
  oysters, 
  is 
  good 
  for 
  those 
  which 
  survive, 
  because 
  they 
  are 
  

   freed 
  from 
  the 
  crowding 
  of 
  neighbors. 
  I 
  suspect 
  that 
  the 
  advantage 
  

   of 
  dragging 
  a 
  dredge 
  over 
  young 
  beds 
  not 
  yet 
  ready 
  to 
  yield 
  a 
  harvest, 
  

   lies 
  not 
  only 
  in 
  the 
  fact 
  that 
  in 
  this 
  way 
  the 
  clusters 
  are 
  forcibly 
  sepa- 
  

   rated, 
  but 
  that 
  many 
  j^oung 
  oj^sters, 
  which 
  w^ould 
  have 
  grown 
  to 
  

   maturity 
  and 
  then 
  crowded 
  one 
  another, 
  are 
  turned 
  under 
  and 
  killed 
  

   by 
  the 
  mud, 
  giving 
  their 
  more 
  fortunate 
  neighbors 
  a 
  better 
  opportunity 
  

   for 
  normal 
  and 
  regular 
  growth. 
  

  

  The 
  excessive 
  crowding 
  to 
  which 
  the 
  o)^sters 
  growing 
  in 
  clusters 
  are 
  

   •subject 
  has 
  been 
  held 
  by 
  Professors 
  Brooks 
  and 
  Verrill 
  to 
  account 
  for 
  

   the 
  fact 
  that 
  such 
  collections, 
  often 
  numbering 
  as 
  many 
  as 
  100, 
  are 
  

   frequently 
  composed 
  entirely 
  of 
  empty 
  shells. 
  The 
  work 
  of 
  Doctor 
  

   Grave 
  on 
  the 
  conditions 
  under 
  which 
  oysters 
  feed 
  lends 
  strong 
  sup- 
  

   port 
  to 
  the 
  opinion 
  that 
  crowding 
  may 
  bring 
  about 
  the 
  death 
  of 
  entire 
  

   clusters, 
  because 
  it 
  is 
  almost 
  certain 
  that 
  the 
  individuals 
  composing 
  

   them 
  are 
  poorly 
  fed, 
  and 
  therefore 
  probabl}^ 
  not 
  so 
  resistant 
  as 
  oysters 
  

   growing 
  alone 
  or 
  in 
  less 
  densely 
  crowded 
  communities. 
  Doctor 
  Grave 
  

   has 
  shown 
  that 
  under 
  normal 
  and 
  favorable 
  conditions 
  a 
  Newport 
  

   Eiver 
  oyster 
  takes 
  one 
  hour 
  to 
  strain 
  333 
  c. 
  c. 
  of 
  water, 
  and 
  that 
  it 
  

   can 
  obtain 
  sufficient 
  nutriment 
  in 
  from 
  two 
  to 
  six 
  hours. 
  The 
  thickest 
  

   clusters 
  of 
  marsh 
  and 
  reef 
  oysters 
  are 
  found 
  where 
  they 
  are 
  covered 
  

   onl}^ 
  during 
  the 
  last 
  hour 
  of 
  flood 
  tide, 
  during 
  slack 
  w^ater, 
  and 
  during 
  

   the 
  tirst 
  hour 
  of 
  ebb 
  tide, 
  and 
  in 
  this 
  brief 
  period 
  they 
  must 
  get 
  their 
  

   food. 
  Thus 
  the 
  maximum 
  time 
  which 
  man}- 
  of 
  these 
  oysters 
  have 
  for 
  

   feeding 
  is 
  little 
  more 
  than 
  the 
  minimum 
  time 
  during 
  which 
  their 
  more 
  

   fortunately 
  situated 
  relatives 
  can 
  procure 
  all 
  they 
  need. 
  The 
  supply 
  

   of 
  food, 
  shortened 
  in 
  this 
  way 
  by 
  a 
  disadvantageous 
  position, 
  is 
  in 
  all 
  

   probability 
  still 
  farther 
  diminished 
  as 
  a 
  direct 
  result 
  of 
  the 
  crowding. 
  

   The 
  densitj^ 
  wnth 
  which 
  the 
  elongated 
  03'sters 
  are 
  packed 
  makes 
  it 
  

   almost 
  certain 
  that 
  the 
  water 
  containing 
  their 
  food 
  passes 
  through 
  

   more 
  than 
  one 
  set 
  of 
  gills, 
  and 
  the 
  amount 
  that 
  each 
  individual 
  can 
  

   extract 
  will 
  depend 
  on 
  the 
  number 
  of 
  times 
  that 
  the 
  water 
  has 
  alread}^ 
  

   been 
  strained. 
  Only 
  the 
  first 
  oj^ster 
  securing 
  a 
  giv^en 
  quantity 
  of 
  

   water 
  has 
  the 
  opportunity 
  of 
  extracting 
  from 
  it 
  all 
  the 
  diatoms 
  that 
  it 
  

   contains. 
  

  

  While 
  there 
  seem 
  to 
  be 
  good 
  reasons 
  for 
  believing 
  that 
  the 
  ill-nutrition 
  

   and 
  the 
  crowding 
  of 
  oysters, 
  caused 
  by 
  their 
  location, 
  may 
  account 
  for 
  

   the 
  fact 
  that 
  so 
  many 
  of 
  them 
  die, 
  there 
  is 
  another 
  possibility 
  which 
  

   must 
  be 
  taken 
  into 
  consideration 
  in 
  explaining 
  the 
  large 
  numbers 
  of 
  

   clusters 
  of 
  empty 
  shells. 
  It 
  is 
  no 
  rare 
  occurrence 
  for 
  many 
  of 
  the 
  

   animals 
  inhabiting 
  the 
  sand 
  flats 
  to 
  be 
  killed 
  at 
  law 
  tide 
  by 
  the 
  great 
  

   heat 
  of 
  the 
  midsummer 
  sun. 
  There 
  can 
  be 
  little 
  doubt 
  that 
  the 
  oysters 
  

   also 
  sufl'er 
  during 
  these 
  periods 
  of 
  too 
  high 
  tejnperature, 
  and 
  it 
  is 
  very 
  

  

  