﻿288 
  .REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  organic 
  bodies 
  wliicli 
  find 
  such 
  conditions 
  favorable, 
  but 
  at 
  the 
  same 
  

   time 
  many 
  of 
  these 
  organisms, 
  particularly 
  the 
  diatoms 
  and 
  zoospores, 
  

   are 
  attracted 
  to 
  the 
  surfa(;e 
  by 
  the 
  sunlight 
  and 
  are 
  thus 
  jjlaced 
  beyond 
  

   reach 
  of 
  the 
  oyster. 
  In 
  rainy 
  or 
  stormy 
  weather, 
  however, 
  they 
  are 
  

   driven 
  down 
  toward 
  the 
  bottom, 
  where 
  they 
  may 
  be 
  brought 
  withhi 
  the 
  

   influence 
  of 
  the 
  cilia, 
  and 
  at 
  the 
  same 
  time 
  there 
  is 
  an 
  increase 
  in 
  the 
  

   amount 
  of 
  other 
  organic 
  sediment, 
  much 
  of 
  which 
  is 
  available 
  as 
  food. 
  

  

  Shallow 
  water, 
  as 
  a 
  rule, 
  produces 
  more 
  food 
  than 
  the 
  greater 
  

   depths, 
  owing 
  largely 
  to 
  the 
  fact 
  that 
  it 
  warms 
  more 
  quickly 
  and 
  thus 
  

   increases 
  the 
  vitality 
  of 
  both 
  the 
  oyster 
  and 
  its 
  food. 
  The 
  latter 
  shows 
  

   its 
  greater 
  vigor 
  by 
  a 
  more 
  rapid 
  multiplication, 
  and 
  the 
  former 
  by 
  its 
  

   greater 
  consumption 
  of 
  the 
  food 
  which 
  is 
  thus 
  provided 
  for 
  it. 
  In 
  other 
  

   words, 
  the 
  chemical 
  and 
  physiological 
  changes 
  resulting 
  in 
  the 
  conver- 
  

   sion 
  of 
  inorganic 
  matter 
  into 
  oyster 
  tissue 
  through 
  the 
  medium 
  of 
  plant 
  

   life 
  go 
  on 
  more 
  rapidly 
  iu 
  the 
  presence 
  of 
  warmth. 
  It 
  must 
  also 
  be 
  

   remembered 
  that 
  the 
  shallow 
  waters 
  are 
  generally 
  of 
  a 
  lower 
  density 
  

   than 
  the 
  deeper 
  ones, 
  and 
  this 
  apj)roach 
  to 
  brackishness 
  appears 
  to 
  be 
  

   also 
  favorable 
  to 
  the 
  production 
  of 
  food. 
  

  

  Summer 
  and 
  fall, 
  the 
  seasons 
  of 
  most 
  vigorous 
  growth 
  of 
  aquatic 
  

   vegetation, 
  are 
  in 
  most 
  localities 
  likewise 
  the 
  best 
  seasons 
  for 
  the 
  

   growth 
  of 
  the 
  oyster, 
  while 
  in 
  winter 
  the 
  food 
  supply 
  is 
  at 
  a 
  minimum, 
  

   the 
  vital 
  activities 
  of 
  the 
  oyster 
  are 
  much 
  reduced, 
  the 
  ciliary 
  action 
  i:^ 
  

   weak, 
  and 
  the 
  oyster 
  in 
  a 
  state 
  of 
  semihibernation, 
  both 
  the 
  waste 
  and 
  

   repair 
  of 
  tissue 
  being 
  reduced 
  to 
  a 
  minimum. 
  

  

  That 
  the 
  oyster 
  iu 
  many 
  places 
  reaches 
  its 
  greatest 
  fatness 
  and 
  per- 
  

   fection 
  late 
  in 
  fall 
  is 
  due 
  partly 
  to 
  the 
  quantity 
  of 
  food 
  produced 
  during 
  

   the 
  summer 
  and 
  partly 
  to 
  the 
  cessation 
  of 
  the 
  drain 
  which 
  the 
  act 
  of 
  

   spawning 
  entails. 
  Shortly 
  before 
  and 
  during 
  the 
  spawning 
  season 
  

   most 
  of 
  the 
  nutrient 
  matter 
  in 
  the 
  food 
  is 
  utilized 
  in 
  the 
  rapid 
  growth 
  

   of 
  the 
  sexual 
  products, 
  but 
  after 
  the 
  cessation 
  of 
  spawning 
  it 
  is 
  con- 
  

   verted 
  into 
  surplus 
  ^protoplasmic 
  matter, 
  which 
  is 
  stored 
  up 
  in 
  the 
  

   tissues 
  and 
  thereby 
  renders 
  the 
  oyster 
  fat 
  and 
  well 
  flavored. 
  

  

  ENEMIES. 
  

  

  At 
  all 
  stages 
  of 
  its 
  career 
  the 
  oyster 
  is 
  preyed 
  upon 
  by 
  more 
  or 
  less 
  

   dangerous 
  foes. 
  It 
  might 
  be 
  supposed 
  that 
  an 
  animal 
  inclosed 
  in 
  a 
  

   ponderous 
  armor, 
  which 
  in 
  times 
  of 
  danger 
  is 
  a 
  complete 
  encasement, 
  

   would 
  be 
  free 
  from 
  the 
  attacks 
  of 
  enemies, 
  but 
  no 
  organism 
  has 
  ever 
  

   evolved 
  a 
  protective 
  device 
  which 
  some 
  other 
  organism 
  has 
  not 
  found 
  

   partially 
  vulnerable; 
  and 
  it 
  must 
  be 
  remembered 
  that 
  the 
  oyster 
  is 
  not 
  

   always 
  as 
  well 
  protected 
  as 
  we 
  find 
  it 
  in 
  the 
  adult 
  and 
  marketable 
  con- 
  

   dition. 
  In 
  the 
  young 
  state, 
  before 
  attachment, 
  the 
  minute 
  and 
  delicate 
  

   fry 
  is 
  fed 
  upon 
  extensively 
  by 
  the 
  adult 
  oyster 
  and 
  by 
  other 
  mollusca, 
  

   lingulas, 
  worms, 
  sponges, 
  and 
  hydroids. 
  Upward 
  of 
  200 
  young 
  have 
  

   been 
  found 
  in 
  the 
  stomach 
  of 
  an 
  oyster, 
  and 
  there 
  is 
  but 
  little 
  doubt 
  

   large 
  numbers 
  are 
  so 
  consumed 
  on 
  every 
  oyster-bed. 
  Probably 
  the 
  

  

  