﻿OYSTER 
  INDUSTRY 
  OF 
  NORTH 
  CAROLINA. 
  251 
  

  

  officers, 
  and 
  the 
  crew 
  of 
  the 
  Fish 
  IIa'wl\ 
  from 
  whom 
  1 
  received 
  many 
  

   favors 
  wliile 
  stationed 
  on 
  the 
  vessoL 
  

  

  In 
  the 
  preparation 
  of 
  this 
  report 
  free 
  use 
  has 
  been 
  made 
  of 
  the 
  

   investigations 
  of 
  Captain 
  Smith 
  and 
  Mr. 
  Stevenson; 
  and 
  the 
  chapters 
  

   on 
  the 
  anatomy 
  and 
  development 
  of 
  the 
  oyster, 
  at 
  the 
  request 
  of 
  Pro- 
  

   fessor 
  Holmes 
  in 
  the 
  special 
  interest 
  of 
  the 
  North 
  Carolina 
  oystermen, 
  

   have 
  been 
  reprinted 
  from 
  the 
  United 
  States 
  Fish 
  Commission 
  Report 
  

   for 
  1897. 
  

  

  METHODS. 
  

  

  The 
  exact 
  conditions 
  which 
  are 
  most 
  favorable 
  to 
  the 
  growth 
  of 
  

   oysters 
  and 
  which 
  determine 
  their 
  qualit}' 
  are 
  not 
  sufficientl}^ 
  well 
  

   known 
  to 
  make 
  it 
  possible, 
  at 
  present, 
  to 
  predict 
  the 
  results 
  of 
  oyster 
  

   planting 
  in 
  an 
  untried 
  locality. 
  It 
  is 
  altogether 
  possible, 
  too, 
  that 
  

   sufficient 
  data 
  may 
  never 
  be 
  compiled 
  from 
  which 
  such 
  predictions 
  can 
  

   be 
  made, 
  but 
  the 
  use 
  of 
  accurate 
  methods 
  of 
  observing 
  and 
  recording 
  

   certain 
  of 
  the 
  conditions 
  under 
  which 
  the 
  oysters 
  of 
  different 
  localities 
  

   live 
  is 
  a 
  step 
  in 
  this 
  direction 
  which 
  should 
  be 
  continued. 
  The 
  pub- 
  

   lished 
  observations 
  on 
  the 
  density 
  of 
  the 
  water 
  on 
  oyster 
  beds 
  in 
  

   almost 
  every 
  oyster-producing 
  region 
  along 
  the 
  Atlantic 
  coast 
  are 
  

   such 
  as 
  to 
  be 
  of 
  great 
  value 
  to 
  prospective 
  oyster 
  planters. 
  Other 
  

   factors, 
  such 
  as 
  the 
  general 
  character 
  of 
  the 
  bottom, 
  depth 
  of 
  water, 
  

   and 
  velocity 
  of 
  currents, 
  have 
  also 
  in 
  a 
  few 
  instances 
  been 
  well 
  

   described, 
  but 
  the 
  terms 
  used 
  are 
  usually 
  indefinite, 
  and 
  nothing 
  is 
  

   given 
  concerning 
  the 
  methods 
  employed. 
  In 
  order 
  to 
  have 
  real 
  

   value 
  in 
  comparing 
  the 
  different 
  localities, 
  all 
  observations 
  on 
  the 
  

   same 
  condition 
  or 
  set 
  of 
  conditions 
  should 
  be 
  made 
  according 
  to 
  uni- 
  

   form 
  and 
  accurate 
  methods. 
  In 
  the 
  work 
  of 
  the 
  present 
  survey, 
  

   therefore, 
  considerable 
  attention 
  was 
  paid 
  to 
  this 
  subject, 
  and 
  when- 
  

   ever 
  possible 
  methods 
  already 
  in 
  general 
  use 
  were 
  adopted. 
  

  

  The 
  description, 
  which 
  follows, 
  of 
  the 
  methods 
  used 
  in 
  the 
  work 
  of 
  

   the 
  biologist 
  does 
  not 
  include 
  methods 
  of 
  oyster 
  planting, 
  as 
  they 
  are 
  

   best 
  considered 
  in 
  the 
  chapter 
  dealing 
  with 
  the 
  experiments. 
  

  

  The 
  salinity 
  or 
  specific 
  gravity 
  of 
  the 
  water 
  over 
  the 
  oyster 
  beds 
  

   was 
  determined 
  in 
  the 
  usual 
  way, 
  Hilgard's 
  ocean 
  salinometer 
  being 
  

   used. 
  This 
  apparatus 
  consists 
  of 
  a 
  copper 
  cup 
  for 
  holding 
  the 
  sample 
  

   of 
  water, 
  and 
  a 
  series 
  of 
  three 
  sealed 
  glass 
  floats, 
  each 
  float 
  a 
  cylin- 
  

   drical 
  bulb 
  with 
  a 
  slender 
  stem, 
  the 
  bottom 
  weighted 
  with 
  a 
  small 
  

   amount 
  of 
  shot 
  and 
  the 
  stem 
  containing 
  a 
  graduated 
  scale, 
  which 
  in 
  

   the 
  first 
  float 
  reads 
  downward 
  from 
  1.000 
  to 
  1.011, 
  in 
  the 
  second 
  from 
  

   1.010 
  to 
  1.021, 
  and 
  in 
  the 
  third 
  from 
  1.020 
  to 
  1.031. 
  The 
  weight 
  in 
  

   the 
  first 
  is 
  just 
  sufficient 
  to 
  cause 
  the 
  float 
  to 
  sink 
  in 
  fresh 
  water 
  to 
  the 
  

   top 
  of 
  the 
  scale, 
  marked 
  1.000, 
  the 
  specific 
  gravity 
  of 
  fresh 
  water; 
  as 
  

   salts 
  are 
  dissolved 
  in 
  the 
  water 
  the 
  specific 
  gravity 
  is 
  increased, 
  in 
  pure 
  

   sea 
  water 
  reaching 
  1.023-1.027. 
  Float 
  No. 
  1 
  is 
  therefore 
  used 
  for 
  

   determining 
  the 
  specific 
  gravity 
  of 
  brackish 
  water, 
  No. 
  3 
  in 
  ascertain- 
  

  

  